Weird problem. Need some suggestions.

[Jagstang]

Alright, so I finally got the S14 sr20det running for the passed 4 days now (previous ECU was tuned for a bigger maf sensor and injectors, current ECU is stock), and put 275 km's on it. Runs great, pulls hard under 3000 rpms (shifting low cause of new clutch break in).

So anyways, yesterday when I got off work, I started the car, and sat waiting while it was idling. Everything was good, vacuum was at -20, temperature was going up normally on the water temp gauge etc. Then out of nowhere, 1 minute through the idling process, the car stalls. It's pretty much instant.

When this happened, I thought it was a little odd, so I gave it a few seconds, and decided to try starting it, and it was just cranking repeatedly.

So after trying many times, I decided to unplug the maf sensor, and oddly, the car started, and idled for a while, and then as soon as I plug the MAF back in, it stalls.

I was thinking it may have been the coolant temperature sensor since the one I was using came with the SR from Japan. So I installed a new one today, and drained out all the water, and decided to add coolant. I then started to bleed the radiator, and it started up fine! Idle was at about 1100 rpms (cold), and 8 seconds later, it stalled. During that period, vacuum was at -19 to -20.

Afterwards, everytime I start the car, it just cranks over and over. So I have to wait 20 minutes until it's fully cold, then I can start it up again (with it lasting only 5-8 seconds before stalling).

Help would be greatly appreciated. So far i've checked all the vacuum lines, and they all seem fine, intercooler pipings are tightened up, running the car cold with the MAF unplugged still has the stalling issue 8 seconds in.

I need some serious help, i'm all ears to what you guys have to say. I'll probably remove the MAF sensor, and spray some MAF cleaner in it, and reinstall it. Before I swapped the engine in, I put a new gasket on the IACV, and also cleaned it up with carb cleaner (with it off the intake). I also cleaned the intake manifold.

Car has a front mount intercooler, atmospheric bov, downpipe, exhaust, apexi air filter (minor stuff). Help would be greatly appreciated! Thanks in advance.

[corn322]

Can you keep it alive with the gas pedal?

[Hoffman5982]

.......Have you diagnosed the MAF??

[Jagstang]

Can you keep it alive with the gas pedal?

No, unfortunately I can't keep it alive with the gas pedal. RPM's go up, then stalls after a few seconds.

.......Have you diagnosed the MAF??

I'm not 100% sure if the maf is bad, but yesterday I tried getting the car to idle by removing the MAF sensor, but it still stalls. During the few seconds of idle, the vacuum is at about -14 or so. So I don't see why I can't duplicate the stuff from the other day (how the unplugged MAF allowed the car to idle). So it must be something else.

I'm thinking there's some kind of leak (due to the -14 idle). But I already checked over all the vacuum hoses, and haven't seen anything odd

Also, why is it that every time I start the car once, and try to start it again after it stalls, it just cranks? The car runs for under 10 seconds, and doesn't even get hot, how can it not start up after? Doesn't make any sense to me.

[mastakilla08]

try the 02 sensor i had a very simular problem and the car would run when the 02 was unplugged...this was on a ca20 motor out of a 200sx though lol

[Lobo240sx]

Can you keep it alive with the gas pedal?

No, unfortunately I can't keep it alive with the gas pedal. RPM's go up, then stalls after a few seconds.

.......Have you diagnosed the MAF??

I'm not 100% sure if the maf is bad, but yesterday I tried getting the car to idle by removing the MAF sensor, but it still stalls. During the few seconds of idle, the vacuum is at about -14 or so. So I don't see why I can't duplicate the stuff from the other day (how the unplugged MAF allowed the car to idle). So it must be something else.

I'm thinking there's some kind of leak (due to the -14 idle). But I already checked over all the vacuum hoses, and haven't seen anything odd

Also, why is it that every time I start the car once, and try to start it again after it stalls, it just cranks? The car runs for under 10 seconds, and doesn't even get hot, how can it not start up after? Doesn't make any sense to me.

Sr's never made sense when diagnosing lol. I'd check your turbo outlet bolts where it bolts to the manifold. Something probably got loose or has a tiny hole in a vacuum line. Even the smallest holes can cause all kinds of weird problems. Make sure your throttle body I/C piping coupler is all the way back to the line. I'd check the grounds as well.

[Jagstang]

try the 02 sensor i had a very simular problem and the car would run when the 02 was unplugged...this was on a ca20 motor out of a 200sx though lol

Ok, I just tried this, and the car ran for 20 to 30 seconds then stalled. I think the reason it lasted a little longer was due to the fact that I didn't start it in a long time.

Sr's never made sense when diagnosing lol. I'd check your turbo outlet bolts where it bolts to the manifold. Something probably got loose or has a tiny hole in a vacuum line. Even the smallest holes can cause all kinds of weird problems. Make sure your throttle body I/C piping coupler is all the way back to the line. I'd check the grounds as well.

The turbo outlet nuts are good, I changed the gasket, and tightened them down nicely, and bought those new oem pieces that lock the nuts in before I swapped the SR in. I also put some green thread locker on the outside of the nuts, so it should be good. I think there might be a leak on one of the hoses, but it doesn't make sense why it idled well during those 20+ seconds, then just shuts off.

[Razi]

Any ECU codes?

I'd check the ignition electrical stuff.

[Jagstang]

Any ECU codes?

I'd check the ignition electrical stuff.

Alright, well I don't have the Nissan data scanner to connect to the port to check for ECU codes, but we tried a working MAF sensor on it today, and it didn't change anything. Still runs the same. I tried giving gas, and the car was idling longer, and as soon as it started to drop, I gave it more gas etc, then a FAT backfire happened (loudest backfire i've ever heard), and the car stalled.

Waited a good 20 minutes, started it, and it ran fine for 10 seconds or so, then stalled.

[Razi]

You can still check the codes manually via the screw and LED on the ECU, can't you?

[Jagstang]

You can still check the codes manually via the screw and LED on the ECU, can't you?

No man, it's not possible. That only works on S13 ECU'S. As for today, I decided that the grounds might be causing this since the spark plugs are giving off such a weak spark. So I connected 2 fatty 10 gauge wires, and extended the coilpack ground to the head, and tried starting it. Unfortunately, it's still doing the same thing.

It did idle much longer/smoother too, for like 30+ seconds, but then soon after, it just sputtered and stalled. Is there a method to test for an electrical short? Someone told me about a trick where you turn the car off completely, then disconnect the negative or positive, and put a light to it. . . And if it lights up, there's a short somewhere.

[asoomal]

Grab yourself a multimeter and check for shorts and opens. -_-

You're shotgun approach pleases me.

Regretting it aren't ya? :P

Told ya so, Bub

[thomasjamal]

Also try checking and cleaning all your grounds.

[Jagstang]

Also try checking and cleaning all your grounds.

Yea, I sanded all the grounds for the engine, I haven't checked over the lower harness grounds tho, but I'm pretty sure those grounds wouldn't cause the problems i'm experiencing tho. As for the engine having shorts, I'm starting to think that it's not a possibility. The car ran perfectly for 4 days, drove without a single problem too.

It's too consistent, engine idles perfectly, and as soon as a specific amount of time passes, it bogs and tries to stall (when I added the extra grounds, it now tries to fix itself but shortly after it stalls). I don't know, this could be fuel injector problems. Either that, or something with the idle air control valve, throttle position sensor, cam angle sensor, coil packs, etc.

[asoomal]

How about you test them all?

[Jagstang]

How about you test them all?

IACV was cleaned with carb cleaner, and has a new gasket. Throttle positon sensor was working during those 4 days, I don't see why it would fail. Cam Angle sensor was replaced with another working one that doesn't have a cracked casing. And I highly doubt all coilpacks wouldn't work after 20 seconds of idling.

Injectors are the last thing on the list that I can think off. Oh and the ignitor works, since the car is able to start up.

[OutToWinPAHC]

Sounds like it doesn't like closed to open loop..... Why are you driving it with a new ECU untuned when it required a tune?

[kouki munster]

Is there any type of alarm system in the car?

[asoomal]

Just take it to a shop already, you don't have the skill or experience to diagnose it anyways, or the tools either.

You bought the cheapest SR20 off Ebay and then installed a s*** load of Megan/CS parts and had s*** wiring done to it and now you're wondering why doesn't it run right?

Any shop will be able to scan it, as long as you kept the scan tool port...right?

[Jagstang]

Sounds like it doesn't like closed to open loop..... Why are you driving it with a new ECU untuned when it required a tune?

To answer your question, when they ship the engines from Japan, the only thing that stays together is the harness, engine, and transmission. All the ecu's and sometimes maf sensors go in their own container.

When the guys I bought it from received the engine, they thought it was a zenki SR, so they took pics of the engine's ad with the zenki ecu. But then they realized that it was a kouki S14 SR, so they took a random Ecu from their inventory, and shipped my engine with it. With my luck I got a tuned ecu.

Is there any type of alarm system in the car?

Yes, it has a compustar alarm system with an immobilizer.

Just take it to a shop already, you don't have the skill or experience to diagnose it anyways, or the tools either.

You bought the cheapest SR20 off Ebay and then installed a s*** load of Megan/CS parts and had s*** wiring done to it and now you're wondering why doesn't it run right?

Any shop will be able to scan it, as long as you kept the scan tool port...right?

Umm ok, let's see all the stuff I've put into this engine before and during the swap.

Walbro High Flow Fuel Pump Kit

SPEC Clutch Kit Stage 1

Nismo Engine Mounts

Peak Performance Pro transmission Mount

Koyo radiator

OEM Nissan Radiator Hose Set

OEM Nissan Thermostat

OEM Nissan Water Pump Assembly

OEM Coolant Temperature sensor

Gates Belts

Tomei Rocker Arm Stoppers

Circuit Sports Plenum Intake Spacer Gasket

Complete Nissan Engine Gasket Kit

KTS 3" Downpipe

Circuit Sports Turbo Elbow

Cusco shifter bushing

Stance Water Neck Adapter

Mishimoto FMIC

CX Racing Intercooler pipings

Vibrant Vacuum hose kit

Hmm, the only CS products I see is the intake spacer, and the turbo elbow. Seriously, stop coming in my threads with the intention of trying to stir **** up, this is not helping.

And yes, my car still has its port. . .

[asoomal]

There's a lot more haha :P

Such as the CS downpipe, which didn't fit so you had to go get the KTS one.

Not trying so stir anything up, just saying, you gotta pay to play. Had you done what I told you, you wouldn't be having this problem.

[kouki munster]

Make sure that the alarm isn't having a brain fart and causing your problem.