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 .

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Frank_Jaeger

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.

__________________
under cover brother

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

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

teh smithers

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

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

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

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.

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

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).