32 Gtr Not Starting

[mojave15]

R32 GTR has been full rebuilt with forgies, all the usual. Installed the engine started it set timing etc and drove 10ks and parked. Now car will not start. Wierd thing is it run for a coupla hours while we were setting it all up. No mechanical noise etc. Was missing on the way back on light to medium throttle which I figured could've been AFM's.

Engine turns over fine, tries to spark the first coupla rotations then wets the sparkies.

Things we've checked so far

- Fuel is getting thru. Maybe even too much, wet's the sparkies after a couple of turns.

- Have spark, tested with a coil out, although seems weak.

- Tried different CAS and set timing

- Tried different Ignitor (PCU)

- Removed and reseated fuel rail

- Tried different ECU

- Tried different Sparkies

- Reset Computer and TPS

- Checked Front mount hoses

- Cleaned AFMs

- Checked for kinks in return fuel line and fuel pressure

- Cleaned fuel filter

- Checked fuses

Car has:

Splitfire Coils

Stock ECU

Forged Pistons

N1 Oil

Fully Balanced bottom end

Head has been rebuilt and ported

Metal Head Gasket

Stock Injectors and stock pump

Did a ECU diagnostic come up with CAS, Knock Sensor and Ignition. Swapped the CAS and it cleared ignition and CAS, only knock sensor comes up intermittantly. There were a coupla grounding cables we missed connecting on top of the coolant inlet but these are connected now.

I've been thru every post I can find but can't find anything I haven't already tried. Any ideas of what else to check would be much appreciated.

Cheers,

J

[blind_elk]

CAS is in the correct position? Locating key in end of exhaust cam is still there?

Leaking injector(s)? What is the fuel pressure?

REPLACED fuel filter?

Camshafts still aligned correctly (not skipped a tooth on the belt)?

What spark plugs?

The knock error is because of a fault in the knock sensors, not because you have knock. But it shouldn't prevent the engine starting.

[mojave15]

CAS is in the correct position? Locating key in end of exhaust cam is still there?

Yes and Yes. Spins freely.

Leaking injector(s)? What is the fuel pressure?

Injectors were tested professionally before install we've taken em out since anyway and put em up to the air compressor no leakage. Fuel systems all stock (injectors, FPR, pump) we've taken the hoses off and run the pump. Plenty coming thru.

REPLACED fuel filter?

Haven't replaced it but you can whistle thru it. Besides fuel's getting in fine. Covers the sparkies.

Camshafts still aligned correctly (not skipped a tooth on the belt)?

Haven't taken that off yet, I'll have a look but it was all on tight and running a coupla days ago.

What spark plugs?

Tried iridiums and standard BCPR6ES coppers. Iridiums are a 7 I think, they were working in the car before the build.

The knock error is because of a fault in the knock sensors, not because you have knock. But it shouldn't prevent the engine starting.

Yeh, figured that. Just thought I'd mention it.

Oh and we've tried running it with another car + battery so it should've had plenty of juice to start.

Cheers,

J

[blind_elk]

Have you tried starting it with WOT?

[Swiper the Fox]

how old is the fuel in the tank?

we needed to fully drain and flush system when we rebuilt ours. Even adding fresh fuel wasn't enough to keep it running.

[mojave15]

I'll try WOT start when I clean the plugs again.

Fuels only a coupla days old now was pretty much empty when we put the engine in, so put some new stuff in, but it did start and run for a coupla hours on the original fuel before that. Filter and lines appear clear, and it pumps thru fine when we disconnected the rail.

[mojave15]

Tried the WOT start, no go. Tried to fire twice as usual then flooded the plugs.

We took out all the plugs and coils grounded em and rotated the CAS manually, it's weird 1 and 6 spark strongest the other's spark occasionally. Possibly the coil harness but a bit strange as it idled fine for a coupla hours when we were setting and testing it.

Thanks for the suggestions sofar. Any other ideas?

Edited September 3, 2008 by mojave15

[blind_elk]

You need to hold WOT until the engine is well and truly running. You don't back it off just because the engine sounds like it's about to fire. Or is having an initial "coughing fit".

[mojave15]

Yeh, we held it, it doesn't get to the coughing fit tho. Just spins sounds like it's trying to ignite twice and then floods the plug.

Would anything else have an effect on the spark other than the ignitor. We rotated the CAS manually you can hear the injectors clicking open normally, but the sparks just seem really weak. Only 1 and 6 seem to spark with any consistency. Things doing my head in now.

Another post said something about a relay next to the ECU causing a similar prob. I can't find any other info on it tho.

[GTScotT]

have you mesured the voltage on the afm while cranking to make sure its not the afm besides cleaning it, because if its stuffed and mesuring like 3 or 4 volts then its going to be adding wayyy to much fuel to start

[mojave15]

AFAIK you should still be able to run the car with the AFM's disconnected. We've tried that, I'll check the voltage tomorrow.

Tried a different coil harness today as well as measuring the fuel pressure. Sitting on 275kpa no restriction on the return line.

Guess I'm gonna have to recheck the timing, don't get how it jumped teeth still feels tensioned all fine. Everything was done up to factory specs. weirdest prob I've had yet.

Cheers,

[mojave15]

Sorted it. Looks like I didn't tension the belt up properly and it jumped like 4 or 5 teeth. Purr's like a kitten now.

Thanks for all the advice and help.

Cheers,

[babyskyline]

You didnt do any damage because it jumped a few teeth???

Very lucky in my opinion.

Edited September 8, 2008 by babyskyline

[apl]

I have the exact same problem on my build. Your timing belt jumped some teeth?

[Godzilla32]

Gotta make sure you tension the belt correctly accross the section that goes from the crank back upto the top. Checking the other side is a false reading. Also you MUST wind the engine over at least 2 revolutions once you initially set the belt tension. Then recheck all marks and crack the tensioner bolt again and let it reset or make your own final adjustment.

I also think you are very lucky not to have bent any valves with 4 or 5 teeth skipped.