SR going lean under heavy throttle/WOT

[jscherf92]

Hey guys, I haven't had to do this in a while but im seriously scratching my head on the latest round of SR troubles.

-Blacktop SR20
-ISIS T25/28 Replacement Turbo
-Stock 370cc Injectors
-Stock MAF & 3" cone filter
-Tubular Exhaust mani
-Freddy Intake Mani
-ISIS 255LPH Fuel Pump
-Aeromotive Adjustable FPR
-Stock head/head gasket/block
-Recirc'd BOV, Internal Wastegate
-New O2 Sensor, new knock sensor
-TPS, O2, MAF, CAS, IACV all functional

and I've got a zeitronix wideband and working CONSULT port

On to the problems...

The big thing im worried about is timing. I've got it set as close as I can tell to the right points on the gears and the dots on my CAS line up but its nearly maxed out clockwise when trying for 15 degrees and a timing light.

When its idling around 850 RPM my consult display will show timing jumping anywhere from 9-15 degrees. Under light throttle it will rise and stabilize. AFR at idle is typically around 14.5-14.9 warm. AFR under light load/crusing also says in that range, low 14's to 15.

Additionally, and this one downright scares me, under heavier throttle the AFR will actually start to climb instead of go down into the 12's. Fuel pressure is set to 43psi and does increase with throttle but until I can get an electric pressure gauge I dont know what it's doing under the heavy throttle.

According to my consult data, the injector duty cycle isn't maxed out or even above 40% but if the wideband is reading accurately then it's ridiculously lean and dangerous. Boost gauge will read up to 7-8psi but there is no noticeable increase in power, which leads me to believe the fuel system isn't keeping up.

I'm trying to avoid having to get a MAF/Injectors/ECU because I really didn't think the turbo would be different enough to hurt anything but this really has me wondering.

Hit me with ideas, questions, comments and ill try to update tomorrow afternoon.

[ultimateirving]

If you have consult working. Try using "conzult" and use the "base idle adjustment" mode, it puts the car in timing mode and you can adjust the idle thru the iacv, and make sure the timing is sitting steady at 15*

[Kingtal0n]

Hey guys,

The big thing im worried about is timing. I've got it set as close as I can tell to the right points on the gears and the dots on my CAS line up but its nearly maxed out clockwise when trying for 15 degrees and a timing light.
afternoon.

THIS IS A HUGE PROBLEM RIGHT HERE. Do not boost the car because it sounds like your ignition timing is wayyyy off right now. I am surprised the engine isnt knocking and detonating like crazy (do you have a loud exhaust? And can't hear it?)

You either
A: have the timing light incorrectly connected
or
B: The camshaft is off a tooth

The CAS should be pretty centered with the timing set right. I'll go for option A and say you need to turn the pickup (clamp) around, they are directional on most timing lights and report incorrectly when reversed. If A is correct then your base timing is set somewhere around 30* right now instead of 15.

All of your other symptoms point to this (I just finished reading your list). you are losing power because the ECU is having a panic attack everytime you boost it.

[jscherf92]

If you have consult working. Try using "conzult" and use the "base idle adjustment" mode, it puts the car in timing mode and you can adjust the idle thru the iacv, and make sure the timing is sitting steady at 15*

I've been using the free/demo mode of conzult and have been able to use the base idle adjustment setting to dial in the idle speed and when adjusting the timing it will keep a steady reading on the pulley so I believe it is in timing mode.

THIS IS A HUGE PROBLEM RIGHT HERE. Do not boost the car because it sounds like your ignition timing is wayyyy off right now. I am surprised the engine isnt knocking and detonating like crazy (do you have a loud exhaust? And can't hear it?)

You either
A: have the timing light incorrectly connected
or
B: The camshaft is off a tooth

The CAS should be pretty centered with the timing set right. I'll go for option A and say you need to turn the pickup (clamp) around, they are directional on most timing lights and report incorrectly when reversed. If A is correct then your base timing is set somewhere around 30* right now instead of 15.

All of your other symptoms point to this (I just finished reading your list). you are losing power because the ECU is having a panic attack everytime you boost it.

Yeah I've been keeping a very very close eye on the boost gauge and staying out of transition and boost since I noticed this. I've suspected timing for a while but I need to make some time to pull the valve cover and take a closer look. As for knock/detonation I'm not hearing any problems, it does idle and cruise smoothly and I recently reinstalled the cat to quiet down the exhaust but its not a straight pipe or anything.

As far as the timing light goes, ill give it a try connected in another direction, its a pretty basic Actron unit and im pulling signal from a spark plug wire on the #1 coilpack.

Thanks guys for the replies ill check back tomorrow night after work with any progress or updates. Any thoughts on the reading for timing within the consult software? should it be bouncing around or locked at a constant reading? I know this is ignition timing but im concerned about it bouncing around as much as it is.

[Kingtal0n]

It bounces because the ecu is trying to hold the idle steady. timing "mode" temporarily disables that feature; in fact thats about all it does.

Don't you see your knock sensor lighting up like a christmas tree? Stop focusing on the computer and focus on the engine, you dont need any fancy software to set your timing, what the engine tells you by how acts is good enough right now.

[jscherf92]

Alright, I don't see any feedback or codes from the knock sensor but I know that it can retard timing in the event of knock/detonation. It makes sense that the engine would adjust timing to compensate for idle speed. I may not be able to pull the valve cover until tuesday morning but we'll see.

[Kingtal0n]

why are you pulling the valve cover. I said reverse the pickup on the timing light first, did you try? It will read 20*+ difference. The cas needs to be nearly center.

http://i23.photobucket.com/albums/b378/draglarry/to_clean/P1200499.jpg

[jscherf92]

Would pulling signal from the coilpack harness provide a better source than a spark plug wire between the coilpack and the plug itself? thanks for the pic btw.

[ultimateirving]

Would pulling signal from the coilpack harness provide a better source than a spark plug wire between the coilpack and the plug itself? thanks for the pic btw.

Not necessarily, his point is that you could have the pickup on wrong

[jscherf92]

Alright so im using Conzult for timing mode, RPM right around 860-875, temp at 185F, MAF 1.64V, TPS 0.38V. I pulled signal from the middle coilpack #1 wire just like in your photo and adjusted the timing from there, it was advanced a good bit and now the CAS is much closer to center. Idle AFR is slightly more rich than before, between 13.8 and 14.5 vs 14.5-15.0 previously. I'll make some observations on my way to work today and report back later this evening. Thanks for the help so far!

[jscherf92]

I should add that flipping the timing light pickup didn't seem to make any difference, But pulling signal from the coil signal wire rather than a spark plug wire did. The engine ran pretty poorly on my way to work today, hesitation, some bogging, overall limited power and still going lean under load. I'm going to double check my spark plugs tonight, they've caused problems in the past. Also Power balance test was fairly consistent across the board.

[ultimateirving]

I should add that flipping the timing light pickup didn't seem to make any difference, But pulling signal from the coil signal wire rather than a spark plug wire did. The engine ran pretty poorly on my way to work today, hesitation, some bogging, overall limited power and still going lean under load. I'm going to double check my spark plugs tonight, they've caused problems in the past. Also Power balance test was fairly consistent across the board.

It sounds like conzult helped to verify you were in timing mode, and able to set it up properly. I would definitely try some new plugs. At around stock power levels bkr8 should be fine

[Kingtal0n]

take of picture of your cas, where the bolts are. If you need me to take one first I can.

[jscherf92]

How it sits now. Was pretty much limping the entire way home. Serious hesitation, felt like it was in the wrong gear the entire time. I've got the day off tomorrow to go over everything, ill be replacing the fuel filter and spark plugs depending on how they look. If there's anything else I should check or inspect before running to the parts store, let me know.

http://i58.tinypic.com/imrm36.jpg

Edit; Previously it was almost fully advanced. Sorry for the fuzzy pic, there's an intercooler pipe in the way.

[jscherf92]

Another update; installed a brand new set of BKR6E plugs, gapped to 0.030" as well as the purolator equivalent Z32 fuel filter. Adjusted my throttle stop screw, IACV, CAS, TPS several times trying to isolate the best combo.

Right now i've got the throttle stop screw back where it should be, just barely touching the throttle stop when closed and TPS is adjusted to 0.36V closed and hits 4.06V at WOT.

Unplugged the IACV to adjust to idle around 800, that seemed to be where the engine adjusted timing the least, holds around 15 according to conzult.

CAS is slightly more advanced than yesterday.

http://i.imgur.com/y1kMQ7Al.jpg

It should be noted that I got about a 13 degree difference in timing signal from two separate sources, from the black wire loop on the back of the coilpack harness I can read 15 degrees, while getting signal from coilpack 1 shows about 2 degrees.

I've read a lot of conflicting things about where to pick up timing signal, the first time I set it from coilpack one off of a spark plug wire, the second time (when it ran the worst) was off of the signal wire going into coilpack one, and now just to try something different I am using the reading from the loop on the back of the head.

All things considered, it seems to be running a bit better, idle is nice and smooth, it does not stall under deceleration nor hesitate on acceleration. It still wont go into a rich range under boost but it doesn't climb above 15 like it did previously.

I am going to try increasing fuel pressure a bit at a time to see if I notice a difference. I don't know if having the fuel pressure regulator so far from the fuel rail (about 2' of hose from end of rail to fpr) makes a difference or not, considering the stock FPR was bolted directly to the rail.

[Kingtal0n]

pictures of the engine bay please, especially pcv routing, and maf location, air filter,

And if possible, vacuum lines, and also snap the front of the engine


You have a stock ecu right? what number E5 J4 62 etc...
Get me the part# off the maf, it should be 69Fxxxx or similar to that

and last, have you done a boost leak check (by filling the plumbing with air via air compressor) if not that is your next step, along with a compression test, cold and hot. And we need to fix your ignition timing once and for all. I still do not think it is right by looking at the picture. I will take a pic of mine for ref. The fact you keep getting different numbers at different wires tells me that your timing light may not be up to the challenge. I think you might want to get another one, if for no other reason than to have a second opinion.

The easiest noob method is:
take the signal from the coilpack wire as shown in the picture.
Check your timing and look at the CAS. If the cas is nearly center, that is correct orientation.
if the CAS is way off, flip the pickup and check again.
Once you think you have it "set" you should hand tighten the CAS bolt, then check again, then tight the bolt, then check again.
Yours is neither close to center nor far off. It makes me think you just need more practice with the timing light.
Because the stock camshaft has the stock gear on it, the cas will always be in the same place on every engine when it is set to 15*btdc like factory.

[jscherf92]

Stock E5 ECU; MAF Part number 22680-52F00; I've done a boost leak test but it wouldn't hurt to do it again, and ill ask around about borrowing a timing light from a buddy, mine is functional but its definitely on the cheaper side.

Ill go take a few pics but here is a basic diagram of my PCV/Vac setup
http://i.imgur.com/hxMplF8.png


Edit; Engine bay pics.

http://i.imgur.com/BD96fZel.jpg

http://i.imgur.com/p3Paswpl.jpg
Recirc'd BOV, vac sourced from TB, hose from Valve cover to catch can only pinched to take CAS pic, wastegate source from compressor outlet nipple, MAF directly after rubber intake pipe, short adapter from maf to cone filter.

http://i.imgur.com/9A0qAeVl.jpg
Engine front, excuse the oil stain, we were doing some other cleaning in the garage, not running AC, large baffled oil pan

http://i.imgur.com/dPrqumEl.jpg
Intake side, Freddy manifold & S14 throttle pulley, Aeromotive FPR, vac hoses connected underneath intake mani for FPR and boost/vac gauge. Hoses run to valve cover fitting and brake booster (w/one way valve). Remote mount oil filter.

http://i.imgur.com/wMlZ3mUl.jpg
Engine bay.

If you need any more specific pics or diagrams, just ask, I really appreciate your help and patience.

[Kingtal0n]

It looks good. Did you do the work yourself? did you install the air filter bracket yourself?

#1 is we need to fix your timing once and for all (to repeat)

#2 dont worry about boost leaks right now, b/c your wot condition is lean. I was just hoping you had done one, at some point
#2.5 do a compression test if you have not done it, and write down the numbers, and whether it was hot or cold.
#3 What did the old plugs look like? white?

#4 Do you have a compressor map for that turbo? HOW MUCH BOOST are you trying to hold? Oh please, please tell me 7psi...


So here are your next steps, once you dial in the timing,
If the lean condition persist then you are obviously not getting enough gas. That means either the fuel pump, the lines(blockage), or the ecu simply isnt tuned for your turbo at whatever boost you are using. the fix is a tune, but to VERIFY that it is the TUNE and not the FUEL SYSTEM you should raise your fuel pressure... alot. Try 70PSI-78PSI and boost 7psi to see if your A/F's will go rich. If they stay lean, and basically do not respond to the additional pressure, you have a fuel pump issue or blockage.

Alternatively, it could be the maf of course, but I think you tried another one? and cleaned yours right? very unlikely (rarely the maf is a problem) but noteworthy
And many other small details... but we shall start with the easy large issues first (fuel pump / pressure / timing / compression)

[jscherf92]

Yeah this was a garage build, the air filter bracket is definitely ghetto and temporary but it keeps the maf and filter in place for now.

#1, this will be my focus tomorrow night and all day thursday, I plan on double checking the timing chain and gears, as well as the CAS gear position.

#2, alright, previously I had two small leaks and fixed them, I don't believe I have any serious leaks right now but ill likely check again in the near future.

#3, old plugs were light grey/brown with no apparent damage or excessive fouling.

#4, unfortunately I dont have a compressor map but it is the Isis T25/T28 and i have set the wastegate to the stock 7psi and I have not once boosted higher than that since installing it. I can tell you its exhaust side is 0.86 A/R. I only intended to use it as a stock replacement because my stock T25 had excessive shaft play.

I'll get to work on the timing when I can and do a thorough inspection of the fuel system. Right now it is an ISIS 255LPH pump connected to the stock wiring, the fuse and relay are both functioning normally, the pump is run to the hardlines under the car, then to the new z32 fuel filter before going into the rail. After the rail ive got about 2' of braided stainless hose and the aeromotive FPR then back to rubber line and the factory hard line. I just ordered an electronic fuel pressure gauge so I can get an idea of what my FPR is doing when driving and If need be I can swap in the OEM FPR, although the aeromotive was just rebuild with a new diaphragm and thoroughly cleaned. Ill certainly try that fuel pressure adjustment, I've read a few cases where a slight bump in pressure was able to solve similar problems. Hopefully I can avoid any sort of ecu tuning or adjustment because not only am I completely unfamiliar with it, i know that its expensive and potentially time consuming. The goal with the replacement turbo was to stay as close to stock as possible to avoid ecu issues.

I know i've said it several times but thanks again, obviously I'm not entirely prepared for this engine but its been a project for some time and I can't give up now.

[Kingtal0n]

if the fuel pressure test works, actually, you will never want to leave it that way for long. Instead find alternative means, there are many other easy ways to make a maf car get richer if the headroom is there. the fuel pump is one of those parts on the list of common parts that can break or work poorly without the owner realizing because the symptoms are so spread out and you always "just put that brand new pump in there so eliminate it"

Also we have been assuming the car really is going lean because your wideband says so. now that you are exploring all these options you should consider the legitimacy of the widebands report. Which by the way, where is the sensor installed?

[jscherf92]

Its a zeitronix zt3 with the Bosch sensor installed on the top side of the downpipe, about 3" before the cat flange. Just installed new exhaust gaskets about a month ago and there are leaks to speak of. No flex section on the downpipe either, so it should be pretty accurate. The gauge will display lower values when shifting for example and goes all the way lean when engine braking so it seems to be functional.

[jscherf92]

Would my tps voltage being 4.06 at WOT be causing a problem? I've read a few threads where its as high as 4.5 and if there's a 'closed flag' is there also a WOT flag?

If I'm using my tps to lower idle speed I could be hiding the the larger timing problem due to the relationship between idle speed and base timing. I might be confusing myself but its a thought. I've also found a MAF to buy if mechanical timing checks out.

Also I'm gonna take a close look at fuel pump voltage and possibly install a relay/new 12v wire since my battery is already in the trunk.

[Kingtal0n]

I Never bother with the tps because it has very little influence on anything. The car should run and drive pretty normal without the tps. I have never seen a serious problem due to a faulty tps. I think you are looking in the wrong place. Did you try raising the fuel pressure? do this before you even think about pulling the valvecover. I seriously doubt there is anything wrong with your mechanical timing, as that would be an incredible coincidence.
cas picture has to wait a day I am not going back out tonight

[saadyrt]

I like it.http://webb.erebook.com/1.jpg

[jscherf92]

Alright, im trying the fuel pressure adjustment early tomorrow morning. Don't sweat the CAS pic i know it should be about centered across its range of adjustment.

I like it.http://webb.erebook.com/1.jpg

What?

[jscherf92]

Quick mid-day update; set CAS back using signal from cylinder 1, it's still almost fully advanced but will show 15 degrees and a proper idle speed.

Found the fuel pump was only getting 10.3 volts, replaced a length of wire and it raised to 10.8, hardwired it with a 4pin relay and am now seeing 12+ volts on the fuel pump cover terminals, also added a ground while I was at it.

The fuel pump alone didn't change AFR under boost, however I did a quick drive with fuel pressure at 60psi and i managed to get AFR down to 13.0 under boost (from previous 15-16). I am gonna try around 75 as you suggested and see if that has a greater effect.

[Kingtal0n]

Okay, if raising the fuel pressure is working to lower AFR during boost (and you feel the engine making power), you have a MAF/ECU (tune) issue, because clearly the fuel system is supporting the power (fuel volume).

Also, dont run the engine hard if the cas is not about centered. Something is very very wrong if that is how it wants to run. The only way to get that as "proper" timing is
1. chain is off a tooth
2. adjustable camshaft gears

[jscherf92]

Alright, another run at 70psi got me into the 12 and high 11 range so it seems to hold true.

It's definitely making more power like it used to, quite some time ago before the old t25 crapped out. I'm getting pretty consistent readings from TPS and MAF as far as increased voltage with increased throttle, however neither one is hitting its high value at WOT. I'm going to do some more investigating and troubleshooting, probably remove the valve cover just to double check the CAS position and cam timing.

I'm not out yet but i feel like i can see the light at the end of the tunnel. Thanks again for the advice so far.

Edit; quick follow up question, should I be at all interested in the injectors right now? The resistance measures fine, they seem to be functional but is the potential issue purely ecu/maf or could the injectors be in need of a thorough cleaning and professional inspection? My thought is that they can keep up at a higher pressure, so either the ECU isn't allowing them to stay open long enough or they're dirty/clogged enough to restrict flow at the proper psi.

[Kingtal0n]

you are over thinking this. The ECU simply takes a maf voltage, and converts it to a fuel pulse. If it's running lean because the fuel pulse is too short, then the maf voltage is too low, or the tune is set such that it is holding the injectors open too short per unit maf voltage. Either way (longer pulsewidth in the ecu, or more maf voltage) will fix your issue, if you have the injector headroom. So you could, install a SAFC-II and dial up the maf voltage manually, that is exactly what an SAFC does (is designed to do).

Alternatively you could make a boost leak. the maf voltage would increase, and more fuel would inject. that is not a practical solution however for many reasons, but it illustrates the simplicity of the situation: maf -> tune -> injectors. chasing tps voltage has no affect here.

Raising fuel pressure worked because your pump can support the volume at higher pressures (a good diagnostic sign, now please turn the fuel pressure back down before it ruins something, this is just a diagnostic approach, not a fix).

As to the injector cleaning. It would only help if they are all actually equally significantly "clogged" or gummed up. That would also be quite a coincidence, every injector being equally clogged, enough to make you run that lean. Years of accumulated deposits would do it; they are not hard to change either, so it's worth a shot if you have a spare set or a means to clean them. Sure why not.

Ultimately I think you are looking at changing the maf (perhaps yours is simply filthy? or old? It happens.) Or going safc / stand-alone to correct the issue. I just have a hard time believing that turbo is so much better at 7psi that it causes you to run that lean. It just doesn't make much sense on a maf car. Hopefully changing the injectors / maf will fix this problem.

cliffs;
turn the fuel pressure back down
try a different maf
doesnt hurt to clean injectors
finalize the ignition timing with the cas centered like OEM

also, for the sake of completeness, check the maf wiring and ground. You may be losing a potential difference somewhere. (very unlikely, doesn't hurt to check though). In fact check all grounds. ground by the battery tray, ground on the intake, ground is tight on the battery, grounds by the ECU are tight also. check the ecu plug is tight also.

Higher voltages make injectors open easier, but still within a specified range (there is a maximum voltage we do not wish to approach.) so I am not asking you to upgrade anything only verify oem outputs. And I am only mentioning that at all because you seem to wish to be thorough in your investigations. Make sure the alternator and battery is good and well connected to run your electronics, often, even if the car is running normal.

[jscherf92]

Will do. Thanks for spelling it out for me, that makes a lot more sense.

[jscherf92]

Quick update, ill be back as i work through the troubleshooting today.

Compression Test Results
(Average over 5 tests, warm but cooling down)

Cylinder 1 - 124 psi
Cylinder 2 - 120 psi
Cylinder 3 - 133 psi
Cylinder 4 - 125 psi

I know FSM is looking for 156 with a minimum of 128 and difference between cylinders no greater than 14. Obviously my results are pretty low, but they're consistently low.

I can also add that fuel pressure does increase when it should, so the regulator is doing its job. I've ordered injector filters and o-rings just because so ill be refreshing those when they come in.

[Kingtal0n]

Quick update, ill be back as i work through the troubleshooting today.

Compression Test Results
(Average over 5 tests, warm but cooling down)

Cylinder 1 - 124 psi
Cylinder 2 - 120 psi
Cylinder 3 - 133 psi
Cylinder 4 - 125 psi

I know FSM is looking for 156 with a minimum of 128 and difference between cylinders no greater than 14. Obviously my results are pretty low, but they're consistently low.

I can also add that fuel pressure does increase when it should, so the regulator is doing its job. I've ordered injector filters and o-rings just because so ill be refreshing those when they come in.

Great! Good work, good progress.
A note about compression, are all the plugs out when you take a reading? Cranking speed is very important. Your results might increase 10-15psi if you get a second battery connected (jumper cables) and remove all the plugs, and ensure the throttle body is open when you do the test.
Cylinder 3 is asking you to take a closer look. Is something inside it? Is there oil residue hanging around? Are the valve seals good on that cylinder? Why is it slightly higher than the rest? Try adding oil to all cylinder, and see what happens. if they all go up (to meet #3) except number 3, then you have an answer...

[jscherf92]

I already notice my errors, I only removed one plug at a time and the TB was most definitely closed. I'll run another test while I still have the tool and report back. I just took some solace in the fact they were all relatively close to one another. I've been checking wire continuity between individual sensors and the ecu and so far they're all checking out so its unlikely that wiring is a problem. I'll keep at it when I can find more time. Very busy week between working retail and upcoming final exams...

[KendallH]

1. Stop listening to kingtalon, half the things he said are either wrong or dumb.

2. Lean condition is cause by one of two things: too much air post-AFM or too little fuel.

3. Since you would be under positive pressure after the turbo, your intake leak would be between your turbo and AFM, disconnect and plug everything between the AFM and turbo and then check your results.

4. If you still experience a lean condition after that test then your issue is fuel. I would first inspect the tank and in-tank fuel filter. Check to make sure you have 12V at the pump. Wiggle the wiring connectors to see if it changes. Switch back to a stock fuel pressure regulator if you can.

[jscherf92]

There's no need to make an attack out of it, we've done some decent brainstorming so far but I appreciate all the help I can get.

I'm looking at the AFM being another name for the MAF so the only thing between that and the turbo is the rubber intake tube. I'll check over it thoroughly, I've got a small vacuum port plugged and the other two are going to the catch can and BOV recirc fitting.

After the air test I'll double check everything in my fuel system and I'll pick up some more fuel line to test the stock FPR just to eliminate another variable. Pump is new and hardwired, tank was removed and thoroughly cleaned, all new z32 filter and lines, I'll be replacing injector o-rings soon and that just leaves the hard lines between the tank and engine bay.

[jscherf92]

New info, performing the compression test correctly got me 140-145 psi across the board so im no longer concerned about that.

OEM FPR made no difference at all, plugging all holes in the intake tube also yielded no change and i cant find any holes or cracks in the tube itself.

Ill be doing another leak test tonight. So far the only change in AFR under boost is from the increased fuel pressure.

[jscherf92]

Car ran like shit today. Started right up on the way to work, no real issues to speak of. After work and later in the night it didn't want to start unless I really played with the gas pedal, rpm's kept dropping to ~500 at idle, fluctuating AFR values, engine shaking horribly. Got home and it looked like the fuel pressure was bouncing around a little (maybe 5psi) and it smelled like hot, almost burning rubber. I got a reaction from unplugging each injector individually, nothing was loose, diconnected, melted, or broken that I noticed. I don't have time to dig any deeper tonight but this is incredibly frustrating for it to get worse so suddenly. Hopefully I can take a look at it tomorrow morning and figure out whats wrong...

[jbjslambert]

was reading back a little bit. this is clearly a non-metered air leak meaning that its sucking in air on your inlet pipe between your MAF and turbo, OR an intake leak. Spray brake cleaner all around the maf area between the maf and turbo an watch for a spike in AFR at idle. may need to rev it up and hold it since it seems to happen more at higher rpms. also spray all around vacuum hoses and intake gasket.

sorry for bad typing...

[jscherf92]

Will do, thanks for the input. Ive got couplers on the way to replace the old rubber tube with 2.5" hard piping. When that comes in ill swap it in and check for intake and boost leaks. I've been wanting to overhaul the intercooler couplings and clamps for a while so checking them all now is as good an excuse as any...

[jbjslambert]

Will do, thanks for the input. Ive got couplers on the way to replace the old rubber tube with 2.5" hard piping. When that comes in ill swap it in and check for intake and boost leaks. I've been wanting to overhaul the intercooler couplings and clamps for a while so checking them all now is as good an excuse as any...

intercooler coupler replacement is always a good thing, but i dont think this is the problem you are having...Boost leak will make it run rich. Boost is metered air that has already gone through the MAF. Leak boost out, and now you have less air in the combustion camber than the MAF read. Therefore, rich conditions.

[jscherf92]

Makes sense. New couplers should be waiting on my doorstep.

On my way to work today I had a situation where I started off from a stop light, made it to second gear and just lost all power. Wideband read full lean, vacuum gauge would still change with throttle but absolutely no response from the engine. I have to assume it was some sort of random fuel cut but my laptop wasn't hooked up at the time so I dont have any log information to tell me what was really happening. I'll add that turning the engine off and starting it back up solved whatever problem it was and i was able to drive away normally.

Hopefully tonight I can limp it home, install my new intake pipe, check everything for leaks and go through more tests tomorrow.

Edit;

It did it again on the way home, full stop at a red light, went to accelerate and got about halfway through the intersection before it started bogging and went full lean. I'm working my way through the intake pipe and hoses that come off of it and haven't found any leaks yet...

More edit;

Still can't figure out timing but i've yet to get a look at the CAS position on the exhaust cam. Went through my intake piping and fixed a couple of very small leaks with 20 psi and soapy water, couldn't see or hear any more. The intake hard pipe idea didn't work out as planned, the couplers were too long and not as flexible as i had hoped but the rubber tube held pressure when tested. Ill have tomorrow night, all day wednesday and some of thursday to keep poking at this, if anyone has any more ideas or suggestions let me know!

[jscherf92]

Reporting back on the off chance that someone is keeping up with this over the holdiay.

Removed my fuel injectors and 3 of the 4 lower o-rings were knicked/ripped and i can't find anyone selling them locally so that's putting me on hold for a bit.

In the meantime i've reset my tps sensor, backed the throttle stop screw all the way out, got a look at the TB butterfly and adjusted the screw so its just barely holding it, and set the TPS to 0.44v when closed and 4.08v WOT. Nice smooth readings across the range and TPS closed flag at 0.50v.

Hopefully I can get to the dealership early friday morning and get the o-rings to re-install the injectors and move on with further testing. The last time I drove it was slightly more rich than usual, I wouldn't be surprised if the o-rings were leaking and causing some problems. I've gone over every hose, pipe, coupling, and clamp for leaks and found nothing, I also replaced the vacuum line going to the BOV and FPR with a nice thick wall hose.


More developments....
Got the valve cover off, forgot to take pics of the previous setup but I got it to TDC, pulled the CAS and repositioned it. I can say that it was off position but I don't know by how much.

TDC, 2nd mark from left.
http://i.imgur.com/z9l7qapl.jpg

Everything I can find shows this as correct, 1.5 links to the left of the intake cam mark, 9 links between dotted links, 3.5 links to the right of the exhaust cam mark. Let me know if this is wrong. Disregard the silver links, the gold link on the crankshaft gear isn't correct.
http://i.imgur.com/X4m0ZNYl.jpg

CAS dot lined up with the left dot on the shaft.
http://i.imgur.com/GJwSX67l.jpg

Much better positioning so far.
http://i.imgur.com/K1KPWO1l.jpg

[ultimateirving]

Awesome man. Timing will be a major Improvement in engine driveability. I'm crossing my fingers for you. You will have something to be thankful about for tomorrow ;P

[jscherf92]

Haha true that, im sure the family will stare with confused faces when i say im thankful for correctly set ignition timing.

[jscherf92]

Tonight's info, just finished installing new injector lower o-rings and now have a steady fuel pressure reading (38 under vac, 43 atmospheric) on my gauge. Also after removing the valve cover I reinstalled it with all new gaskets and sealant.

Current Warm Idle Readings:
*Idle set to 15 degrees from spark plug wire cylinder 1
CAS set more clockwise but not maxed out.
RPM: ~850
MAF: 1.52 V
TPS: 0.36 V
IACV/AAC: 10%
O2 Sensor: Fluctuating normally
A/F Alpha: 108%
Inj Pulse: 2.4 mSec
Inj Duty: 1.68%
Wideband AFR: 13.5
Vac: 18 inHg

Current Warm Idle Readings:
*Idle set to 15 degrees from coilpack harness loop OR black/yellow wire to coilpack one
CAS Set more counterclockwise but not maxed out.
RPM: ~825 (Much more fluctuation)
MAF: 1.66 V
TPS: 0.36 V
IACV/AAC: 10%
O2 Sensor: Fluctuating normally
A/F Alpha: 113%
Inj Pulse: 3.3 mSec
Inj Duty: 2.10%
Wideband AFR: 14.1
Vac: 16 inHg

Noticeable differences:

Idle/timing hunting when set from coilpack signal wire, fluctuation in MAF signal (hundredths of a volt), more rapid fluctuation in timing, slightly less vacuum and slightly less rich.

When timing is set from coilpack signal wire, the reading from the spark plug wire timing shows to be the first mark on the pulley or 5 degrees ATDC, so a 20 degree difference in ignition timing between reading from the coilpack signal wire or an intermediate spark plug wire. I have tried switching out the coilpacks with no change in this.

Is there any way to completely test a MAF before purchasing a replacement or is it something I should try reguardless? I don't really have a way to test a friends but if I'm gonna buy one its probably going to be a brand new SOHC KA maf.

This is all without actually driving, i'll get to that tomorrow evening. The sweet spot as far as engine behavior seems to be setting timing from the spark plug wire and setting idle speed to about 815. While adjusting the IACV I also backed out the throttle stop screw, this lowered TPS voltage from 0.50 to 0.36 but the throttle closed flag is still set in the ECU and I believe it is closer to how the throttle stop and IACV should be set.

[jscherf92]

Drove to work today, let the car sit for about a minute idling and it stalled out, possibly need to up the iacv. When driving its still lean at WOT, some cruising afrs sat around 15-16.0, it wouldn't lean out when engine braking, but occasionally would go lean for no reason. I'm gonna do some logging and probably order the new KA maf.

[jscherf92]

New MAFS arrived today, the wiring specialties harness is expected to arrive Saturday

[ultimateirving]

How fresh is your o2 sensor also? And I didn't read thru the while thread recently but did you mention it's positioning?

[jscherf92]

O2 Sensor is new within the last three months or so. I've got the older one I can throw on for testing but they should both be functional. It's positioned on the 3" turbo elbow/outlet, basically stock position. I've read that the O2 sensor controls the injectors in low throttle situations and the MAF takes over at higher throttle so that points more towards MAF but im sure an O2 issue could wreak all sorts of havoc too.

New info: I got the SOHC MAF wired up and installed, it seemed to smooth out idle a bit and the voltage readings through consult appear to be in a better range than the original. I am still having timing issues, i'm gonna do some reading and see if there is any step i missed during setup, also checking continuity from coilpacks, injectors, and CAS to ECU. My big concern is the coilpack signal being different from the signal wire to the actual spark plug, I cant imagine there should be a 20 degree difference between the two.

Quick drive; Absolutely no change of AFR under boost. Still reading as high as 15.0. Confirmed fuel pressure on the stock fpr is right at 40 psi with vac attached and it does raise with load. I think that just about narrows it down to an ECU issue, aside from the timing problems. I suppose if the timing was off far enough, an added load would only make that worse and its possible that fuel wouldn't be injected in the right interval to make it into the cylinders? I don't know enough about the inner workings of the ECU to do any further testing here but with basically everything being stock its very frustrating.

Alright, I got my hands on an english sr20 manual, ill be checking all of the sensors and components as well as the ecu wiring (some have been shortened/lengthened).

[hyd3official]

@jscherf inbox me that manual boss.

[ultimateirving]

If I recall correctly, Wide band o2 sensors normally should be about 12-18 inches from the turbine. So if it's right on the turbo elbow you could be cooking the o2 sensors or getting bad readings.

[jscherf92]

Oh no sorry the narrowband ecu o2 sensor is in the elbow, the wideband is on the tail end of the downpipe, about 3" before the flange that bolts to the cat. I'm going through and testing all the voltage, resistance and continuity today. Hopefully something presents itself, I tried logging on my way home but couldn't get it to stall like it has been.

[jscherf92]

I might have finally made some progress. I resealed the PCV fittings on the intake side, both on the intake manifold and the valve cover, and managed to get the AFR down into the 13's at 7psi. Since it was previous in the 15's this is a huge improvement already. I'm gonna go over all of my fittings and seals and probably put together a venturi smoker or something to test for more leaks.

Max readings under boost from consult:
RPM: 3975
TPS: 3.46V
Injector Pulse: 14.16mS
Duty Cycle: 36%
Air Flow: 3.92V
AFR: 13.0-14.0 (approx)