Stupid Evil Cam '97 Avenger

Head gasket had a leak, so I pulled it, changed cam(Uncle owns a custom cam shop), built a header(I am a steel fabricator/machinist by trade) and built a custom exhaust. Now damn car only makes 5-7 inches of vacuum at idle. Runs fine when above 1000 rpm. Idles at 650+-. No, vacuum leaks(smoke checked it)/won't throw a code (even when accessing OBDII), and no change when increasing exhaust backpressure(put foot over exhaust). Timing seems to be correct(set TDC with dial indicator). Dunno what the problem is?? Too much cam?? Cam was custom ground(dunno the specs yet - let Uncle sort it out) Car sat for 3 months during repair. Was given 30 thousanths of inch shims with cam(due to cam grinding) but was told not to put them in unless valvetrain very noisy. Didn't, as valvetrain was only a little noisy. Does anyone think it could be the problem?? If not, any ideas??? Tried propane induction while it was running to see if it was running lean, stalled immediately, seems to be very, very rich at idle???? Stupid computer car!!!!

Any ideas???? Ryan

Wrong forum, moving to the correct one.

TS out

Can you please post your cars info I'm guessing you have the 4 cyl 420a. Do you have any other aftermarket or upgrades to the car that you haven't mentioned?

Head gasket had a leak, so I pulled it, changed cam(Uncle owns a custom cam shop), built a header(I am a steel fabricator/machinist by trade) and built a custom exhaust. Now damn car only makes 5-7 inches of vacuum at idle. Runs fine when above 1000 rpm. Idles at 650+-. No, vacuum leaks(smoke checked it)/won't throw a code (even when accessing OBDII), and no change when increasing exhaust backpressure(put foot over exhaust). Timing seems to be correct(set TDC with dial indicator). Dunno what the problem is?? Too much cam?? Cam was custom ground(dunno the specs yet - let Uncle sort it out) Car sat for 3 months during repair. Was given 30 thousanths of inch shims with cam(due to cam grinding) but was told not to put them in unless valvetrain very noisy. Didn't, as valvetrain was only a little noisy. Does anyone think it could be the problem?? If not, any ideas??? Tried propane induction while it was running to see if it was running lean, stalled immediately, seems to be very, very rich at idle???? Stupid computer car!!!!

Any ideas???? Ryan


Ok, the Avenger is a 4cyl 2.0 dohc, automatic. I took out hte lifters, bled them down, shimmed them 30thou(as there was some slack due to the custom ground cams) and it doesn't run much different at all. It seems to have become much more sluggish off the line actually. I'm tempted to just pull the 4 cyl and stuff a 340/ 4speed in it.