Has anyone with comp R lifters had a cold idle problem, and some hesitation if driving before the car warms up? My idle cold goes way up to about 1500rpm, then dies and sometimes will shut off, it goes up and down for a couple of minutes until the car warms up. It does this even when I crack the throttle blades, Also If I just jump in and drive it it hesitates bad until warming up. My Comp R`s are set at 1/8th past zero on a 7/16th stud. I also have the XE 230/236.

Anybody had this problem?

 

JMHO, but I don't think that would be attributed to the lifters. I would be looking for vacuum and intake elbow leaks, to start with.

 

Thanks for the reply. The reason I beleive it the comp r`s set to tight is I have looked for a vacuum leak and found none. I do not hear the whistle of a vacuum leak. One the car warms up the vacuum leak should still be there shouldn`t it? It runs great once warm. Could not the preload be less once the car is warm as the parts have expanded away from the lifter? resulting in less lash and the car running smoother?

 

You don't tell us much about your mods. When you changed lifters, what other mods, if any, were added? Have you checked everthing you did at the time of the lifter install and other changes?

Also, vacuum leaks don't always whistle, although I wish they would to easily locate them.

When the engine warms up things do change size and position, metal expands, etc. This could account for the problem appearing when cold but not at operating temps.

 

stock bottom end LT1, TEA heads, XE 230/236 on a 112, comp r lifters, all the bolt-ons you can think of. ! emissions. When I did the head cam swap from a bolt-on car problem occured w\ cold idle.

I gues I`m asking for those people who have done a cam swap and used Comp R lifters, have you guys had a similar problem w\ the cold idle?

 

I am having the same problem..It is not the lifters. Scan the car, and check what is the IAC counts. Your not getting enough air in. Mine does the exact same thing!!

 

If you still have your E.G.R. system, remove it. I had same thing and now it is totally gone.

 

EGR is gone.


If not getting enough air on idle would there not still be a issue once the car has warmed up? The car runs extremely smooth once warm for a cam`d car at least. Iac counts are not all that bad around 60, and my idle is set a 100rpm higher than stock so it should be over the 20-40 counts for a stock idle setting. The other point is the car continues to sure once I crack the throttle blades, shouldn`t this in theory solve the problem of not enough air?

 

I have a large cam, and I had to crack the blades open quite a bit! What throttle body you running?

 

I have a AS&M ported stock unit 52mm. I did the IAC bypass drill mod and IAC counts are acceptable at around 60. Again it runs great when warm, if I wasn`t getting enough idle air the car would idle rough or cut off coming to a stop once it warms up. It only does this cold.

Car runs great at idle once at operating temperature.

Could someone tell me how its possible to be IAC or vacuum related if the car runs great and smooth once warm, but on a cold start idle is up and down, and is very high even if I give it gas opening the throttle blades?

 

in that case, it wouldnt be a vaccum leak or the IAC. Is the car cammed?

 

I don't have any idle problems.

 

What did you set your valve lash at? What rocker stud size?

 

the mods are a little higher up in this thread, Cam is a XE230/236 on a 112.

 

Yea I just got my comp R's installed last week and I have no idle problems at all. I have the 3/8 inch studs and I set them a little less than 1/8 of a turn after 0 lash. Hope that helps