The Quest For A Healthy SR: Help Appreciated

[teh smithers]

Update 12/18- Motor still runs poorly. Beer still up for grabs.

Should you be the one to suggest the answer that solves the problem, I will have a 6-pack of your favorite beer sent to your house.

New development: Motor idles smoothly at 1800 RPM with MAF unplugged. Fuel smell in exhaust is reduced. MAF plugged back in, idle drops to 1200, becomes much rougher and richer. Please advise.


I've been trying to get my SR to run healthy for over a year. Here are the current issues plaguing its health.

- Has trouble starting up. From a cold start, the motor will crank, sputter, and die on the first attempt. On the second attempt, it sputters, and slowly comes to life. This behavior is consistent. On warm starts, it usually comes to life on the first try.

- Once idle is established, it's very rich. The smell of fuel is apparent in the exhaust, and the idle is rough.

- During the first 2 or so minutes of operation, the motor has absolutely no power from 1000-2000 RPM. It completely bogs down. After the first two minutes or so, it suddenly remembers how to make power in that range, and drives okay again (albeit richly).

- Above 2500 RPM, the motor runs decently for the most part, but it does miss on occasion. I haven't taken it above 5000 RPM since it began to run badly.

What baffles me the most is the fact that this condition didn't occur until AFTER I'd replaced my intercooler system, because the cold pipe had a sizable hole in it from hitting the battery tray. During that time, the motor somehow ran perfectly, everything else being nearly the same as it is now.

Background info about the motor:

- Notch-top SR.
- Basic bolt ons: front mount IC, full exhaust, Garrett GT2860RS on stock boost and tune.

Things I've done that may have caused this issue:

- Installed a new engine/transmission harness from Wiring Specialties.
- Relocated the battery to the trunk, using an Odyssey PC925 battery.
- Installed the new intercooler system.

Things I have tried already:

- Set timing to factory setting with a timing light.
- Tested for boost leaks. Found none. Tightened all clamps for good measure.
- Recirculated my BOV.
- Replaced my O2 sensor.
- Cleaned my MAF.
- Tested TPS for proper voltage. Checked out.
- Checked ECU for meddling. The board is factory.
- Checked and re-checked my install of the harness. Everything looks good.
- Compression test reads 150 across the board.
- Installed new spark plugs (BKR7Es).
- Installed a new coolant temp sensor.
- Replaced IACV.
- Replaced CAS.

If you have any other insight into this matter, please, join me on my quest. If you read this far, you have my sincere thanks.

[codyace]

Sounds crazy, but have you changed your spark plugs?

[jr_ss]

You set time to 15 BTDC? Or 15 ATDC? The way you have it worded with "advanced" in there will throw people off. It shouldn't be advanced, but I'm sure you know this.

Plugs could be a good start as Cody suggested. Have you checked mechanical timing?

[rb25_s13*CHUKI]

do you have a boost gauge? IS your engine properly grounded since the relocation? Sr20's will run like complete shit if they are not properly grounded

[PoorMans180SX]

Sounds like a fuel system or MAF issue. Check the ol' fuel filter and test the injectors.

[Croustibat]

-You cannot say it "runs rich", unless you have a lambda reading. Fuel smell could also come from leakage or blown spark. Anyway, stock tune IS quite rich.

-if you had a hole in your piping, your car could NEVER run well. Unless its ECU system is MAP based, or it has been mapped with that hole.

-hard to start when cold. It can be some things ... badly set timing, not enough fuel delivery, poor spark... or bad compression. Did a compression test already ?

-you DON'T ASK FOR POWER ON A COLD ENGINE. Never. Especially those, unless you want to get an early rebuild.
Anyway these engines won't allow it. They pull timing when cold until a TP load is crossed. They pull like 25° of timing. this is done to warm the car faster and the cats, if needed, and it means you get no power. I found out only recently, making some logs, and disabled it. You cannot, without a tune (and then your tuner needs to know how to do it; they usually don't - i can't map your car either).


Now, your car exhibits symptoms, and you are going to need to do some serious testings.

Things to know though:
most aftermarket temp sensors don't have the same response as the OEM sensor. check that first (thermometer + water + cooker + multimeter are your friends)

there are different O2 sensors depending on which SR20 and ECU you have. Make sure you got the right one.

that cold side piping has the brake booster vacuum line too. Check its condition.

Is your PCV valve ok ? Oil vapor system ok too?

As people said above, it could be ignition related (bad plugs, or plug gap is supposed to be 0.8mm but they are usually delivered with a 1.1mm gap, worn contact between coils and plugs, worn plugs, cooked harness, the list is long).

it could be fuel related, but you are going to need a fuel pressure gauge to test that. Tee it after the fuel filter, block it under your windscreen wiper for testing.
There is the usual "wiring is too thin for the fuel pump" problem, which you can easily check - voltmeter at the pump, voltage needs to be over 14V, if it isn't, time to rewire.

Cleaned up maf ... Meh. Chances are you damaged it. But then the car would really drive badly if you did, so maybe not ... don't touch them, these are fragile things.


Frankly it can be tons of things, so the first thing you should do is use the ECU diagnostic mode to check sensors.

And THEN, once all your problems are sorted, get someone to map it.

[Prok0]

Long shot but did you check to ensure no injector o-rings are torn?

Pop the rail with injectors off the intake mani, turn the key to the on position so the pump primes and see if there is any fuel leaking past the o-rings.

Also can you describe the procedure you used to boost leak test? Did you check the ECU for any fault codes?

[Hoffman5982]

Pull your rail and check to see if any injectors are leaking. Sounds similar to the issues I had, except mine was worse because one was leaking and one was stuck open. Wouldn't hurt to have yours cleaned. Double check your timing. I never got an accurate reading, when I got a reading at all, off the "timing loop" wire on the back of the coil subharness. I'd use a spare piece of spark plug wire and use that method. Definitely double check all of your grounds

[ultimateirving]

You should use a known Good tps to rule out a issues while driving. Not just at idle or with KOEO, also Aspreviously suggested check the spark plugs if you are running rich they will tell you either by color or fouling. Lastly make sure you iacv is completely functional. They have been notorious for sticking and you didn't mention if it's been looked at.
A new cts is a great idea as that tells you ecu how hot the coolant is and therefor how much fuel to use during warm up and at operating temperature

[teh smithers]

I don't feel like quoting everyone, so I'll just answer everything in one go.

Plugs: Done.

Timing: I've reset the CAS to the correct position, and also used a timing light to line things up with the 2nd notch from the right on the crank pulley (IIRC, that's the correct factory setting). I checked it via the spark plug wire method, connected to the coilpack. Should be BTDC.

Boost gauge: Yes, I have one.

Engine grounding: Will be re-doing the battery ground this weekend, 11/6.

Fuel: Will be installing a new filter this weekend 11/6, and pulling the rail if the grounds check out.

Compression test: 150 across the board.

No power when cold: When I say "no power," I mean literally nothing. I'm not trying to get into boost at all- we're talking neighborhood throttle. It just completely sputters and bogs down, and hardly provides any forward momentum whatsoever. Then two minutes later, it returns to normal.

O2 sensor: I'm positive I got the right one. It's the S14 fat-type. It's identical to the stock one I removed, and the connectors match.

PCV valve/oil vapor system/brake booster vacuum line: Will all need to be checked. The brake booster line is the relatively large line that connects to the cold pipe on its underside, near the throttle, correct?

MAF: I cleaned it with a q-tip, to make sure I wouldn't damage it.

ECU diagnostic mode: gives me code 55, no fault codes. I'll double-check again to see if anything changed.

Boost leak test was done by pressurizing the system from the intake inlet with an air compressor. I built my own tester out of a rubber coupler, a PVC cap, and a tire valve.

IACV: I'm not sure how to check it, but I'm sure the answer is out there. I'll check the FSM, but in the meantime, I wouldn't mind someone supplying the answer.

Thank you all very much for the suggestions so far. I'll give everything a go this weekend, and post the results. My offer for beer still stands.

[Croustibat]

ok, i thought you were trying to go on boost. It should still pull timing, but not enough to actually bog the car car down to the point you are describing, and you would hear the turbo spooling early actually. You'd have boost, but nothing near the power you should have at that boost.

As far as setting timing, you are doing it the right way. Ignition is 15° when hot at idle, up to at least 2000rpm. I usually set idle up to 1500rpm just to do it, so the car does not stall.

It is quite strange, ignition related problems would happen more on boost or with heat, not at cold / no load. It sounds like a boost leak, but this would happen all the time. Maybe fuel related. Easiest test to do is voltage at the pump. Then check fuel filter (remove and empty it, try to blow through it; good enough way to check without changing it), and Tee a fuel pressure gauge on it while you put this one or a new one back on it. If you stil have good reading, time to pop the fuel rail. Side feeds on SR20s are known to leak in the manifold when the seal is not put correctly, or worn, so you want to double check that once removed. It just is a pain to do, so better check the easier stuff first.


Also do you have a hot start solenoid on that engine ? If so, you can try removing it. They are known to fail and aren't much use.

The IACV is the idle control valve; it lets some air bypass the closed throttle to control idle. They usually get clogged with time and can stick open or closed. They need a whole strip out / clean. Not that hard to do but time consuming.

[teh smithers]

Also do you have a hot start solenoid on that engine ? If so, you can try removing it. They are known to fail and aren't much use.


I don't think so, unless that's the same thing as the ignitor chip, but I'm assuming that it isn't.

[teh smithers]

Another question: Could it possibly be related to the way I set up my battery? I have an Odyssey PC925 mounted in the trunk. The power wire runs through a 150amp fuse before running up to the engine bay, where I have it connected to a distributor block. Then, I connected the transmission harness power cable to a different post on the block. On another post, I have the two power wires from the fusebox. I see 13.5 volts at both the battery and the distributor block.

[unpaintedhatch]

Have you tried the injector seats or the injectors?
And have you checked the condition of your turbo?
And how is your PCV hoses setup are you accidentally pressurizing the crank case?
Clean your MAF?
If possible check the sock on your fuel filter.
These are all suggestions.

[unpaintedhatch]

Maybe a picture of the engine bay how it sits would be helpful?

[TurboTiger]

Lots of good advice so far. I'm curious to see that the issue was and who wins the beer. Haha

[unpaintedhatch]

Check the one-way valve coming from your manifold to brake booster.

[dreimers]

Another question: Could it possibly be related to the way I set up my battery? I have an Odyssey PC925 mounted in the trunk. The power wire runs through a 150amp fuse before running up to the engine bay, where I have it connected to a distributor block. Then, I connected the transmission harness power cable to a different post on the block. On another post, I have the two power wires from the fusebox. I see 13.5 volts at both the battery and the distributor block.


It sounds like it might be a wiring issue.... To many different things going on. I would not worry about the Wiring Specialties harness.
The way I have my relocation wired is this
Battery to fuse box to disto block in engine bay.
Distro block has ALTERNATOR, RED/Black wire from lower harness, and TWO WIRES from FUSE BOX. I am using 0gauge for my power and ground for the run from the truck to the front. I have my batt. grounded in the trunk to the spare tire hold down bolt. I have 4g running from my alternator to the distro and the main engine ground on the intake is 4g also. Check and CLEAN all your grounds. Make sure they are all around .2-.4 of an OHM. Its amazing how screwed up something gets with bad power flow

[teh smithers]

Edited because I was wrong :(

[teh smithers]

Re-update: Car still runs like doodoo. I think it might have something to do with the battery set-up, as it was one of the things I messed with prior to the car running like doodoo.

The battery is mounted in the trunk. It's an Odyssey PC925, which has 330 cold-cranking amps.
http://s7.postimg.org/ea2fhhvh7/thumb_IMG_2376_1024.jpg (http://postimage.org/)

It's grounded to this former carpet tab, and yes, all paint was sanded off the surface. I plan on making a new ground to the spare tire holder.
http://s7.postimg.org/51097dml7/thumb_IMG_2380_1024.jpg (http://postimage.org/)

http://s7.postimg.org/419ybo7ff/thumb_IMG_2382_1024.jpg (http://postimage.org/)


The power wire runs through this 150-amp fuse...
http://s7.postimg.org/cxkqfly1n/thumb_IMG_2375_1024.jpg (http://postimage.org/)

And terminates at a distribution block in the engine bay. (I have a plastic cover for the block that was removed for the pictures.)
http://s7.postimg.org/rut7gmba3/thumb_IMG_2374_1024.jpg (http://postimage.org/)

Hooked up to the distribution block are the power wire from the battery, the power wire from the transmission harness, and the two power wires from the fusebox.

Did I mess something up here?

My next plan is to make a new ground wire and run it to the spare tire hold-down, and see what happens with that.

[teh smithers]

Also, for those who asked about a compression test: I did the test last night and got 149-150 across the board.

[jdm>usdm]

I would definitely add an additional ground to the spare tire post. The more, the better! I actually have my battery grounded directly to the engine block in addition to my chassis. Make sure you have sufficient grounding from the engine to the chassis. I have grounds from the head, intake manifold, and alternator bracket all to chassis.

Furthermore, make sure your ECM harness isn't too close to any adjacent harnesses. The FSM actually specifies a minimum distance of around 4" to prevent problems due to electrical noise. Keep a reasonable distance between the ECM and its harness from the power cable.

Edit:

Another idea is to connect via consult cable. Even if you don't have codes, you can check and even data log sensor voltages, timing, injector duty cycle, etc... to get a better idea of why your engine is acting up.

[teh smithers]

I would definitely add an additional ground to the spare tire post. The more, the better! I actually have my battery grounded directly to the engine block in addition to my chassis. Make sure you have sufficient grounding from the engine to the chassis. I have grounds from the head, intake manifold, and alternator bracket all to chassis.

Furthermore, make sure your ECM harness isn't too close to any adjacent harnesses. The FSM actually specifies a minimum distance of around 4" to prevent problems due to electrical noise. Keep a reasonable distance between the ECM and its harness from the power cable.

Edit:

Another idea is to connect via consult cable. Even if you don't have codes, you can check and even data log sensor voltages, timing, injector duty cycle, etc... to get a better idea of why your engine is acting up.

I do have my power cable and ECU harness feeding into the engine bay through the same hole in the firewall- the one on the passenger side, near the wiper motor. I believe it's the stock pass-through for the harness. Where else could the power cable pass through the firewall? Any recommendations?

[Frank_Jaeger]

- Has trouble starting up. From a cold start, the motor will crank, sputter, and die on the first attempt. On the second attempt, it sputters, and slowly comes to life. This behavior is consistent. On warm starts, it usually comes to life on the first try.
I had this problem on my old KA24DE and it was the IACV.

[teh smithers]

I had this problem on my old KA24DE and it was the IACV.

Did you manage to clean out the old unit to fix the issue, or did you have to replace it with a new unit?

[jdm>usdm]

I do have my power cable and ECU harness feeding into the engine bay through the same hole in the firewall- the one on the passenger side, near the wiper motor. I believe it's the stock pass-through for the harness. Where else could the power cable pass through the firewall? Any recommendations?

A lot of people do run their power cable through there and don't have any apparent problems, but I personally have mine run through the far hole where the AC line used to run. If you're running through firewall were you are, try to make sure that the power line is routed around the ECM as opposed to directly on top, and don't zip tie the power cable directly to the ECM harness for extended lengths (e.g. as soon as it comes off the ECM all the way to where it splits in the bay). This may only have a small effect on the ECCS, but I suppose it's worth the mention.



Just be generous with the grounding of battery and engine and see if anything changes.

Another Edit:

I removed my comment about the ECCS relay. I just remembered the power from that relay activates the relay for the ignition coils. I wired my car differently from this circuit, so I can get mine to start without the ECCS relay turning on. lol

[teh smithers]

Updates:

Tested voltages over the weekend. Battery showed 14.5 while idling, and the distribution block also showed 14.5. Alternator is healthy.

Also tested for ground resistance. In its current position, my battery ground read .01 or 0 flat. I plan on making another ground cable to the spare tire post, and I'll also try one on the shock tower to see if that makes a difference.

I added a ground from the intake manifold to the chassis. No perceived difference. I intend to ground the head and the block to the chassis as well.

I tried a normal battery with much higher CCAs, and it made no difference.

In short, I'm stumped. It looks like my battery set-up is okay. My next thoughts are to check out the IACV, CAS, and check my injectors/fuel system for problems.

Any more suggestions are greatly appreciated, and again, the correct suggestion will be rewarded with beer. Srs.

[jdm>usdm]

Did you by chance replace that bypass hose that runs from the IACV to the cold pipe when you replaced your IC piping? If so and it's too weak of a hose, it could collapse under the engines vacuum. Might cause hard to start issues, though shouldn't lead to the low power after start problem.

[1Badhatch]

Cough cough if u buy my clutch kit it should fix your problem. -.- <. < >.> I'm not offering an y good advice just trying to make light out of the situation good luck

[Rusker]

Have you pulled the fuel rail to check for leaks?

[cbeuglas]

Check for fuel injector of ring leaks. As described before. Replace maf with a good known working maf. Timing should be set at idel of 750. What is the boost guage reading on vac. Stock should be around 21 at idel. I have seen a bad maf with no code .

Sent from my SAMSUNG-SM-G920A using Tapatalk

[Frank_Jaeger]

Did you manage to clean out the old unit to fix the issue, or did you have to replace it with a new unit?
I tried cleaning it to no avail and then replaced it with a known working one.

[teh smithers]

Update-

I tried moving the battery back up to the front of the car. I grounded to the stock location on the intake manifold. The motor still struggled to start and still ran like crap.

Next steps are to replace the IACV, MAF, TPS, and possibly the CAS.

If all of those fail, I'll check the injectors, but I highly doubt it's that, given the way the car has zero power for the first minute of operation, below 2000 RPM. By zero power, I mean that the car can barely move.

2nd update- TPS is within normal operating spec (tested voltage through full range of throttle). IACV is on the way.

[teh smithers]

Replacement IACV installed; no change. The FSM specifies several procedures for an engine that is hard to start when cold. I'll be looking into those- the CAS, spark, and fast idle cam.

[black'N'proud]

Any updates or progress to your sr20? My guess was the iacv, since on cold starts it seems to be running "sick" like the wax material in the iacv hasn't expanded. Are you running the coolant lines from the block to the throttle body and back to iacv? Good luck, this is an interesting thread.

[Tyler_240]

Have you checked your CTS? I scrolled through, I didn't see it mentioned. I had a lot of trouble with my original SR starting, and it was a number of issue.

Coil Pack Ground was not hooked up to the firewall.

Bad CTS, made cold starts an issue.

Dirty IACV (I stuck the needle of a can of sea foam in the intake tube attached to the cold pipe and had a friend keep the revs going while I sprayed away)

If you don't have the IACV Coolant lines hooked up, it will take longer for it to warm up too, but should still function properly.

Perseverance my friend!

[lok]

What MAF are you using?

S14 sr does not cross over to any US available MAF

[teh smithers]

Have you checked your CTS? I scrolled through, I didn't see it mentioned. I had a lot of trouble with my original SR starting, and it was a number of issue.

Coil Pack Ground was not hooked up to the firewall.

Bad CTS, made cold starts an issue.

Dirty IACV (I stuck the needle of a can of sea foam in the intake tube attached to the cold pipe and had a friend keep the revs going while I sprayed away)

If you don't have the IACV Coolant lines hooked up, it will take longer for it to warm up too, but should still function properly.

Perseverance my friend!

Coil pack ground is hooked up. Brand new CTS installed, along with replacement IACV. No luck there.

[teh smithers]

What MAF are you using?

S14 sr does not cross over to any US available MAF

Stock S14 SR MAF. My next step is to replace the MAF and perhaps the whole intake pipe. With the MAF unplugged, the car holds a healthy idle at 1800 RPM, and the smell of fuel in the exhaust is reduced.

[teh smithers]

Any updates or progress to your sr20? My guess was the iacv, since on cold starts it seems to be running "sick" like the wax material in the iacv hasn't expanded. Are you running the coolant lines from the block to the throttle body and back to iacv? Good luck, this is an interesting thread.

No progress yet, besides the fact that it runs much better with the MAF unplugged. I swapped the IACV with a known working unit to no avail. Truthfully, I wasn't even aware the IACV had coolant lines, but this is a S14 SR20, and it looks like the only inputs on the IACV are electrical. They look completely different from the S13 SR IACV.

[Jorgs_7]

Do you know your exact fuel pressure? Do you know the FPR is working properly?

You ever hear cars struggle to start in parking lots, taking a couple extra seconds? Usually from bad FPR or weak pump.

Try key on, key off, key on, key off. To prime the system.

[teh smithers]

Do you know your exact fuel pressure? Do you know the FPR is working properly?

You ever hear cars struggle to start in parking lots, taking a couple extra seconds? Usually from bad FPR or weak pump.

Try key on, key off, key on, key off. To prime the system.

I haven't looked into the fuel system yet because A) I never tampered with it and B) the symptoms of the car seem like they stem from an electrical issue. If my new MAF and intake don't solve the problem, I'll be looking into fuel.

[Dboyizmlg]

Appears that you have done mostly very thing in the book.

Have you tried swapping with another working ECU?

[Kingtal0n]

I briefly looked at post #1

I can tell you this much,

MAF -> ECU -> Injectors

If you have a problem that comes and goes with the maf, I would look into:
MAF
ECU (and harness) I have seen bad wiring specialties harnesses so do not rule it out
Injectors (and fuel pressure / filter (unlikely))

Use a stock maf, stock ecu, stock injectors, fill the plumbing with 15psi of air pressure, it should hold 15psi for quite a few seconds if there are no leaks. Make sure you block off the crank case (I use a marker) for the test so you do not push out your oil seals or dipstick.

Also, change your plugs are some point, and remember that sensors such as O2 and TPS can be disconnected to help rule them out, but Coolant temp and knock sensor can not, they should be changed or checked for FSM compliance.

[teh smithers]

Appears that you have done mostly very thing in the book.

Have you tried swapping with another working ECU?

Have not yet explored this route, as no one has answered my calls for a red WC ECU. If anyone out there is willing to let me try theirs, I'll cover all shipping costs and put cash on top for the inconvenience.

I briefly looked at post #1

I can tell you this much,

MAF -> ECU -> Injectors

If you have a problem that comes and goes with the maf, I would look into:
MAF
ECU (and harness) I have seen bad wiring specialties harnesses so do not rule it out
Injectors (and fuel pressure / filter (unlikely))

Use a stock maf, stock ecu, stock injectors, fill the plumbing with 15psi of air pressure, it should hold 15psi for quite a few seconds if there are no leaks. Make sure you block off the crank case (I use a marker) for the test so you do not push out your oil seals or dipstick.

Also, change your plugs are some point, and remember that sensors such as O2 and TPS can be disconnected to help rule them out, but Coolant temp and knock sensor can not, they should be changed or checked for FSM compliance.

Replacement MAF is on the way. Will also be making a new intake pipe with better couplers.

Spark plugs, O2 sensor, and CT sensor are all brand new, and made no difference. TPS was tested and is within FSM specs.

I'll run another boost leak test to be sure. Where do you recommend I block the crankcase?

[Jorgs_7]

Seems like you're tunnel visioning. Stop throwing parts at it and ignoring the fuel system.

[teh smithers]

Seems like you're tunnel visioning. Stop throwing parts at it and ignoring the fuel system.

After the MAF, the fuel system is next on my checklist. Based on the symptoms and my own tinkering, I'd assumed it was an electrical issue. I've never touched the fuel system, but I did replace the wiring harness, the intercooler system, and the intake. The weird behavior within the first two minutes of operation didn't seem like it would be traced back to a faulty fuel system either- the way the car is utterly worthless from 1000-2000 RPM; as in, it can barely move itself, and then suddenly, that issue goes away after a couple minutes. But, I am by no means an expert, and perhaps I've been looking in the wrong places. Will update once the MAF and intake are installed.

[LoSt180]

Since it runs better with MAF unplugged, I'd say that's your problem. You also replaced the wiring harness, I'd check that out as well: verify pins with a multimeter, etc.

MAFs can be pretty finicky and can be damaged easily, since you used a q-tip it's possible it could've damaged one of the elements. I usually just spray it liberally with MAF cleaner and let it air dry. Also if it was dropped or placed too hard on the workbench while it was out of the car could've caused an issue.

Another way to verify is to get a consult cable and monitor what the ECU is seeing. I use an ebay Consult 14pin USB adapter, plus an OTG adapter and can monitor my ECU on my phone. Spent maybe $35 on the reader, adapter, and the paid version of NissanDatascan I (free version is also available).