ktm Posted April 7, 2008 Share Posted April 7, 2008 My P90a cam was recently reground after an incident where a hydraulic lifter backed out and collapsed. I just installed the new cam and while the car purrs like a kitten from 1200 rpm on, it idles rough. I was pulling a rock steady 18 in Hg vacuum at idle before the cam incident, now I pull 10 to 12 "shakey" in Hg at idle. However, at 1200 rpm I pull 18 in Hg. No vacuum leaks that I could detect and the car pulls hard and strong through the RPM ranges. I pull 15 in Hg while cruising like normal and I'll go form 15 in. Hg to 12 psi boost in 500 rpm. Still, my idle is rough. I checked the lash on the rockers and as expected with a hydraulic cam, there is no lash. Any thoughts? Edit: I forgot to add that during a high RPM throttle lift, I'll pull 22-23 in Hg which is consistent with my old cam. Quote Link to comment Share on other sites More sharing options...
cholag Posted April 7, 2008 Share Posted April 7, 2008 i dont know much but i did get my p90a cam ground with delta, now i am still working on my motor so i havent started it up. but on the box it says to use high rpm grease or something and when the car starts run the car at 1500-2000 rpms for 20 minutes to break the cam in. the only reason why i say this is because you didnt put that in your post, so that's why i decided to mention it. but if you did do this then i have no clue and sorry for wasting your time. Quote Link to comment Share on other sites More sharing options...
ktm Posted April 9, 2008 Author Share Posted April 9, 2008 Still hoping for some input. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.