ALEV8

Nope still won't start on initial key turn many times, and RPMs drop when coming to a stop. I have latest coils and plugs and 93 octane in it always and ran tons of Techron + through it. I bet it is the failed fuel filter check valve or fuel pump but have not yet wanted to start serious surgery on the vehicle that's my mechanic has been very hard to pin down this year....more pressing is "faulty brake booster".....

CaptJim

Lets pretend the there is no problem with Fuel pressure and Air obstructions. The computer determines idle and engine speed based on many electronic inputs, including the fly-by-wire accelerator peddle. One or more of the sensors that feed into this could be bad?

If you have a fuel pressure problem, you should be able to see this at some fuel pressure tap somewhere. It may even be an option to add a remote pressure sensor to see fuel pressure while driving?

This may be a fun project update. I know on my Cuda, I could not live without my analog Oil pressure, fuel pressure, and vacuum gauge. I am sure some of the racers on this forum will tell you the same.

westy66

im having a slightly lumpy idle when stopped and i feel stuttering while accelerating too. But she hasnt threw up a code yet. maybe i have fuel system issues. shes going to the dealer next week.

b52guy

How did this turn out? I have the same symptoms.

All my coils and plugs have been replaced...

pcst

Based on my personal experience, took mine in (still had a factory warranty at that time), they found few cracked coils and fuel pump went bad. Both were replaced and been smooth ride since then.

Dilberto

Don't forget dirty throttle body and air filter too....

TonyTwoBags

bumping this as my 03 C2 idles 'rough' 1100-1200 rpm for first minute or so on cold start then reliably settles at ~800 rpm and smoothes out. Once warm it gives no noticeable issues. Have the more open intake and it sounds fine throughout the rpm range.

Passed PPI very recently and have put 2.5k on it with some canyon driving and desert highways/fast. No complaints. I figured the starting was just normal warming up, but have seen some detail on misfires.

69gaugeman

This is the tell tale problem. Usually the vacuum tube on the right side of the engine has cracked. It will get worse over time. That or the AOS diaphragm has split.

AGARubberDuck

At first I was thinking 1200rpm idle! Get that checked out/way too high. Then I realize you said C2. This is not the Carrera forum.