96 LQ1 Not Running

[jmgtp]

The belt could be your problem. It could have jumped timing or been installed incorrectly. Pull the front valve cover and verify that the two cam flats in the front are still in synch with eachother. Better yet, run a compression test on all 6 cylinders. If it is low or uneven it would be a good sign you are out of time.

[z34phoenix]

i just had my DOHC jump timing a week ago... shop it was at (i was 2 hours from home) said it had compression... but when i got it home the compression it had was only 30 psi!!! you could see vapor being pushed out of the intake side of the heads when cranking. so intake valves are opening on compression stroke.

[Artemis]

Another thing to note, if I undo the bolts to the plenum, and let some air come in it will run. And it will idle quite nicely in fact. Obviously not driveable, all the extra air counteracts the extra fuel being dumped. Would I be able to do that if my timing was off?

[jmgtp]

Probably not, but loosening the plenum to intentionally create a vacuum leak is a bizarre way of testing things. Why not just use the throttle?

If its running by doing that I'd say your back to having a fueling problem.
You can try a few things:
1) test each injector with an ohm meter, they should be something around 12 ohms each
2) verify that you have correct fuel pressure in the rail
3) pull the fuel rail out of the lower intake and key on to prime the fuel pump and visually verify that none of the injectors are stuck open

[Artemis]

Open throttle isn't enough to keep it running. Open throttle + lifted plenum does the trick. I had it at a mechanic last week, they tested to make sure injectors didn't leak. But, they also noted that pressure was at 60psi at prime. I believe it should be 41-45psi. Could my fuel pump be pumping too hard?

[jmgtp]

Also consider that you may have an IAC problem.

[Artemis]

I've tried 3 IACs....

[jmgtp]

When I had my dohc motor I swapped on a 96 top end. I ran it on a dyno to find that I had a 10:1 a/f ratio. I found 60 psi in the fuel rail as well. The FPR is adjustable on the 96. It usese a torx security bit. I ended up breaking the pin inside the FPR and using a regular torx bit to bring the pressure back down to 43 psi. It ran better.

That said - even at 60 psi in the rail. The thing started and idled just fine.

Do a compression test or pull the valve covers off and visually verify that the cams are still lined up correctly. That is, with #1 at TDC one bank should have cam flats up and the other bank should be 180* out (cam flats down).

[Artemis]

This weekend I reset the timing. Had to be sure the timing was 100% correct. Used the timing guide on this webpage. Unfortunately it didn't do the trick. I was thinking of swapping over the old 95 fuel rail. Seems like a crazy idea that shouldn't work but I'm running out of ideas.

[jmgtp]

A 95 fuel rail won't bolt up to a 96 motor, but you can swap the 95 injectors into the 96 rail. Did you ever try a compression test?

And just to confirm that the cam timing was done right - when the cam flats on the front bank are up the flats on the rear bank should be down (180 degrees different) and vice versa, back flats up front down.

If the cam timing is right and you have compression the it probably brings you back to a PCM issue.

[Artemis]

Yep, cam flats are 180 degrees different at any given time. I'd have to get a compression tester to test the compression. Still to me it seems like its flooding. I've used 2 different PCMs, I guess I could've been unlucky with both, but one was purchased off this forum... it was supposed to be a known good PCM.

[SappySE107]

60-80ms injector load is static open. It wouldn't have a chance in hell of running at idle. Fuel pressure shouldn't be 60 and the computer shouldn't know what the pressure is to adjust anyway. I would back the pressure down to 43.5 and see what that does. Running more fuel injector than the program is set for will cause problems for sure.

You checked the TPS reading right? 0% at idle. Unless the injectors aren't wired properly and firing all 6 instead of 1 at a time, it has to be an input to the computer causing it to fire more than necessary.

[Artemis]

I'm still a little confused as to how I can adjust the fuel pressure. I can't get the car to idle at all, but with key set to ON, I can see throttle at 0%, and if I hit the gas it changes accordingly.

[SappySE107]

Ok cool. Look at the FPR. There is a security torx fitting in it that you spin counter clockwise to lower pressure.

When it runs, what does the MAF read?

[Artemis]

Last time I had a MAF reading it was 0.250lb/min. Also, do I have to remove the FPR to get at the security torx fitting?