When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi,
my 2001 C5 with various mods (aggressive cam, intake, headers x pipe exhaust), sometimes stalls when I press the clutch (for instance after reversing).
when in neutral it idles quit straight at around 900RPM. its the sudden drop in RPM and it dies. doe anyone have a cure for this or is it because of the mods.
Check the PVC system for vacuum leaks, the rubber valve holder can crack in time from the heat and the hoses can swell. If it's leaking air it can also leak oil onto the front of the engine.
My car was running just a little rough a while back...not much though...hooked up the scan tool and looked at some fuel trim data PIDS.....no DTC's except long term fuel trims were running around 13% (anything over plus or minus 10% you worry about) but not enough to set a P0171/0174 DTC...it was a vacuum leak. Hooked up the smoke machine and found a pretty good vacuum leak at the PCV valve where the "condensation band" exits the PCV connector. You can see this in the photo. You can look there !!
Hi,
my 2001 C5 with various mods (aggressive cam, intake, headers x pipe exhaust), sometimes stalls when I press the clutch (for instance after reversing).
when in neutral it idles quit straight at around 900RPM. its the sudden drop in RPM and it dies. doe anyone have a cure for this or is it because of the mods.
I am assuming no vacuum leak, and the problem didn't just randomly start...
There are a number of tune related things to check. I am going through this now. I have a new build Fast 92/LS2 90 TB Comp Cam 231/242 .617/.593 112 LSA (14 degree overlap)
It conservatively made 425 rwhp/393 rwtq on a Mustang Dyno (95 degree day ) It runs great but, rolling idle (clutch-in) was terrible. It would surge/hang/die in parking lots or coming to a stop on the street.
The C5 is a unique beast when it comes to idle tuning. Primarily because as soon as you push in the clutch, the PCM looks at a completely different target RPM and Idle Airflow adder tables. It uses Rolling Target RPM instead of Desired RPM Target. It also uses a Rolling Idle Airflow Adder table for off throttle/clutch-in rolling idle and the Throttle Cracker table for off throttle clutch-out rolling idle. There is also the Throttle Follower table to control how fast the Engine RPM's drops to Idle. I have spent the last three weeks tweaking these with HP Tuners. The difficulty in idle tuning is the high overlap of the cam..
I have mine idling great now. Only little hiccup is a rare slight RPM dip (200 - 300 RPM) on a aggressive stop.
I had the same issue as Bluefire, it's in the tune. To finally fix mine I went to a SD tune. I have a long post in HPTuners forum on this subject.
Got a link? I've been trying to fix random stalls too. 95% of the time my car drives perfect. Then sometimes in traffic (lots of clutch in/out), it'll blow right past my idle RPM and die if I don't give it some throttle.
engine stalls sometimes (modded car)
) It runs great but, rolling idle (clutch-in) was terrible. It would surge/hang/die in parking lots or coming to a stop on the street.
