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*

__________________
Z32 with lq4 swap
Desert Street Scene || Dssevents.com

Kingtal0n

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.

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

jscherf92

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.

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.

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

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

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

__________________
Z32 with lq4 swap
Desert Street Scene || Dssevents.com

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

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

__________________
Z32 with lq4 swap
Desert Street Scene || Dssevents.com

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.



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.



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



Edit; Engine bay pics.




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.


Engine front, excuse the oil stain, we were doing some other cleaning in the garage, not running AC, large baffled oil pan


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.


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)

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

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.

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.

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

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

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.