Rough Cold starts

[zleblanc44]

This ONLY occurs SOMETIMES on cold starts. Trying to start my 08' 135 is usually not so smooth the first turn.

But it does start up, and the idle is really low, feels like it will stall, and if i leave it running the reduced power light comes on.


But it all goes away when i cycle the key and start again....

The car has 57k on it, and all 6 injectors were done 3 years ago along with plugs... And i believe hpfp at some point also since 08'.

(since then, the car has had meth injection, and jb4.. Now is all stock.

Any ideas? I also had the pins on the ECU replaced and corrected because they were damaged from tampering probably. And brought back to stock software.

And by the way no CEL so no codes!!!

Help please!!

[Hellkite]

You can try a few things read this thread
http://www.n54tech.com/forums/showthread.php?t=16481
this thred addresses the issue that some of us have experienced on cold start up.

Also you can try changing your pcv valve. Sometimes they get stuck open at high mileage.
Have you ever done a walnut blast of the intake side of the head. The easiest thing you can try is to put bottle of techron in the next few tanks of gas. Ive herd that carbon can build up in the head. Hope this helps. The teckron trick helped me.

[zleblanc44]

Thank you. I will try the techton trick. I noticed i waited a little bit today to start the car and gave the lpfp a chance to kick in.

Seemed to help a little, but not totally

[stuggy]

I used to have starts where the rpms would stumble (almost sound like the rpms were vibrating), then stumble. Not as bad as the video you posted on n45tech. I ended up having a cracked valve cover and 2 injectors misfiring. Maybe thats your issue, i'm not sure. Your seems to start up fine then almost stall out. Have your dealership check for cylinder misfires, your valve cover, and valve cover gasket.

[marc@x-ph.com]

l could be wrong, and I know you mentioned injectors were new, but still feels like injectors.

Also, did you read codes?