Hey everyone, first off I have to say this is a great forum! A ton of help with previous issues have been solved with it, but now I have one that is stumping me.

My 04' crossfire runs rough on cold starts. It is only for the first 30 seconds - two minutes, and only occasionally, around 2/3 of the time with varying degeees of "roughness." It sounds horrible, low idle, and sometimes won't Rev up at all. Car has about 68k miles, there is no CEL, and it goes away completely after the initial minute or so. If you restart the car even a few hours later, it does not do it... It only happens really on the first start of the day or after sitting a long time.

Any ideas on where to start? I live in a small town in the boonies, nearest european car shop is a 6 hour round trip, and would probably have to stay overnight to let the car sit so I'm trying to avoid that option! Thanks

 

My guess is low voltage, weak battery. If it sits awhile, a marginal battery can easily be below 12volts. It may be enough to get it started, but the low voltage wreaks havoc w/ our electronics, and it gets confused until the alternator juice starts flowing. Next cold start morning, check your battery voltage before you start.

 

Thanks, I'll give that a try tomorrow.

The car sat for about a month a few weeks ago when I smoked a rock and bent a wheel, and it started up and ran perfectly after (actually, better than before sitting) so I'm not convinced that would be it but at this point it's worth a shot! I'll check the battery and update the thread tomorrow.

Intermediate problems are the worst! I'm actually throwing the car up for sale but can't in clear conscience sell it like this. Any other things worth checking tomorrow?

 

Other possible common problems are the CPS (crankshaft position sensor) and the RCM (relay control module). Use the search here; there is all the info. that you'll need; including how to's. Good luck.

 

I'd also say the battery. Sat for a month, might be pumping out stale gas.

 

Something like this happened to me and baffled me for months. Finally I took the car, not the Xfire, to the dealer and a fuel pressure test solved the problem. My fuel pump had failed, low pressure (15 - 20psi I think) and a low volume of fuel. The air/fuel mixture that could be supplied was too lean when cold but OK when the car warmed up.

 

This wold certainly be a likely problem to checkout as well. Seems to me more likely than the battery, but as noted, the voltage sensitivity on the car can cause many issues.

 

Just an update - Replaced both the cam and the crank sensors. I also left the battery disconnected and trickle charged overnight although the charger did say the battery was good and I doubt the battery was the problem.

I plugged the battery in this morning, and holy mother of car alarms! Closing all the doors and the hood, then hitting lock and unlock on the key fob a bunch of times stopped that. The car then wouldn't run at all, after some head scratching and swearing I opened the hood and realized In the hurry I didn't plug in the crank sensor... oops.

Car is running great now after a two month hiatus, I wish I replaced the sensors separately so I knew which it was but my gut is saying cam, since it did start just not run great at first. Hopefully this helps someone else who has the same problem.

 

Classic CPS problem..... Glad you found it...

 

I hope you bought the "Bosch" brand

 

Scratch that, car still runs horrible on cold starts... still misfiring and the odd knock 2/3 times I go to start it. I brought it into a private german auto shop, they must have been lucky because it wouldn't do it for them. They tried selling me onto sparkplugs and injector cleaning, but it seemed the mechanic had a horrible attitude and they seemed extremely unprofessional so it's going elsewhere for another opinion.

Tempted to just get take it to a dealership when it's warm and trade it in at this point. Cps and cam sensor I threw in were Bosch and I have done the RCM fix.

 

check your connections especially the crankshaft position sensor. Cold starts, rough idle are signs of the cps being bad. If not there, then I would look at the fuel rail pressure as 180 mentioned a fuel problem that does happen from time to time. Fuel pressure has to be there for a good start. If not, there may be your problem.

 

Thanks, Ill check that out.

If it wasn't intermittent this would be so much easier