I drove it last night and the idle is choppy but smooths out when you step on it. I am not sure if it is the cam ? Comp Cam 08-501-8. NO CODE. Immediate response. It climbs right through 0-100 no issues. However when I stop it is choppy. Any suggestions ? No obvious vacuum leaks. Went through it again and again spraying brake cleaner and nothing. Fuel pressure was turned up to 60 just to be sure. I will readjust it once we figure out the idle issue.

 

Sounds like a feature not a problem, does it stall?

 

No it doesn't stall. The rpms go up and down its not steady at all. I drove it up to 120mph today. It runs but not perfect. We tried two scanners but neither worked. A third attempt will be made tomorrow. This one will attempt to read each sensor. The ECM is obviously working since the car works. OBD 1 Is making this a little more difficult.

 

Do you have update ? My '86 is exhibiting the same symptoms. I'm going to change the fuel fliter first. I don't have a fitting to attach to the valve on the fuel rail to check the pressure....

 

I said from the beginning I have the Comp Cam 08-501-8 in the motor. Fresh rebuilt motor. Edelbrock 3860 SLP runners ported gasket matched. Gasket matched heads opened up the exhaust a little bit. 24lb Bosch injectors, adjustable fuel pressure regulator, damn near everything is new. Connectors O-rings the list goes on and on ! Anyway my idle now sits at 700. It goes to 600 when in gear and if it sits for awhile it occasionally hits 600-700 this causes the motor to shake a little bit. it is NOT SMOOTH like when it was stock. I went to emissions after work yesterday and sat in a 20 minute line. My coolant temp went up to 245 degrees. When they put a large fan in front of the car it went to 230. When I drove away back in traffic it went to 220. Remember I am in Mesa AZ and our ambient temp was 101. HOT from now till Oct. Anyway I passed very very easy. HC .48 CO 7.35 NOX 1.28 So now I can say with confidence to a buyer it is fine at least by AZ law. Brand new Magnaflow cats with one AIR tube the other O2 sensor. Staggered where the monster cat once was now its a dual. So I have resolved to the fact that my idle is was it is due to my cam change. Put it this way with 2:73 gears that car rips the tires off the street and screams off the line. Not the same car at all. I hit 120mph and never go above 3300rpm. I highly recommend the Comp Cam 08-501-8. Absolutely NO TUNE. Other than the mods I made it is stock. I turned a weak 1988 into a peak C4 that deserves the ZR-1 mags it sports.