Comp Cams 12-304-4 question

[todds302]

running this cam in my pre vortec head 5.7, with TBI and having idle issues, it is stopping at idle, seems to have a miss at idle while sitting in traffic but when your driving it is smooth and torquey. Any help. this is a brand new motor with less than 1000 miles

 

[bot0611]

Iwould check other things before spending or taken the top end apart

 

[GMC1977]

sure it doesnt have valve overlap at idle? me and a buddy just did a motor for his monte carlo and it has a "miss" at idle. just a real rough lopey idle. if thats what you mean then its normal.

 

[todds302]

yeah, thats what it is then, how can i get the idle up on my tbi

 

[GMC1977]

i assume it has a idle control screw just like a carb. most likely where the throttle cable hooks up to the carb. is it dying at idle or you just dont like the lope to it?

 

[4X4HIGH]

That cam isn't very big although the lobe separation is 111* and FI likes closer to 114* but regardless I think you have other issues. You can't just raise the idle on a FI engine without getting into the chip program. All you can set is minimum air and from there the IAC valve controls the idle. I would start by removing and cleaning the IAC passage and CAREFULLY cleaning the pintle of the IAC valve. Also make sure you don't have a bad TBI gasket (common to find a bad one).

 

[todds302]

love the sound it will just die, also the code for the egr comes on and off

 

[4X4HIGH]

love the sound it will just die, also the code for the egr comes on and off

This is VERY IMPORTANT info to have. A stuck EGR valve will cause the engine to not idle properly or at all. You need to pull the EGR valve off and check and make sure that the passages aren't plugged and that the EGR is seating properly. I'll bet you fix this problem and your idle issue will also be cured.

 

[todds302]

will do thanks

 

[todds302]

egr works fine, its only 2 months old, still stalls out and egr light comes on......

 

[todds302]

Well still dont know what i need to do, found a quick fix, used a speaker clip put it on the throttle body and it gave me 300 more rpms so no stalling and it idles around 800, thanks for the help

 

[Thunder]

Check your EGR solenoid it is most likely bad. when it fails they cause the EGR toto open at idle and cause a rough idle/stalling.