Not running right - First Generation Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Not running right
Wednesday, March 02, 2005 11:29 AM
Hi all. I'm pulling my hair out, I'm hoping someone can help before I'm bald.
I have a 86 Z24 that I recently rebuilt the motor. The problem is that once I put the car in gear it hesitates and wants to die. If I bump up the RPM's it seems to do OK. Pickup is not as good as it should be and once I'm in 3rd and punch the gas it doesnt drop the gear or accelerat3e very well.
Now to the fun stuff. The only original parts in the motor are the rods, crank, pushrod guides, injectors, and the block and heads. The cam was upgraded just below the point to where i would have to mess with the ecm. It has Comp Cams 1.52 roller rocker and matching pushrods. I also did port work to the heads, intake and plenium. I have good spark on all cylinders and just replaced the plugs. It has a brand new o2 sensor.
There is also a knock that accelerates with engine rpm. I'm praying that its not the rockers as I left them approx. 1/2 to 3/4 of a turn looser that the originals because at stock specs I was loosing compression.
Help Please, I'm slowly going insane.

Re: Not running right
Wednesday, March 02, 2005 11:40 AM
[Hi all. I'm pulling my hair out, I'm hoping someone can help before I'm bald.
I have a 86 Z24 that I recently rebuilt the motor. The problem is that once I put the car in gear it hesitates and wants to die. If I bump up the RPM's it seems to do OK. Pickup is not as good as it should be and once I'm in 3rd and punch the gas it doesn't drop the gear or accelerate very well.
Now to the fun stuff. The only original parts in the motor are the rods, crank, push-rod guides, injectors, and the block and heads. The cam was upgraded just below the point to where i would have to mess with the computer. It has Comp Cams 1.52 roller rocker and matching push-rods. I also did port work to the heads, intake and plenum. I have good spark on all cylinders and just replaced the plugs. Cranking compression is as follows 1,2,4,6 are at 115; 3,5 are 120 and 123 respectively. It has a brand new o2 sensor.
There is also a knock that accelerates with engine rpm. I'm praying that its not the rockers as I left them approx. 1/2 to 3/4 of a turn looser that the originals because at stock specs I was loosing compression.
Help Please, I'm slowly going insane.
Re: Not running right
Wednesday, March 02, 2005 6:49 PM
what cam did you put in??? id try following the cam manufacterors specs for setting preload on the rockers. usualy i set them by spinning the pushrod with my fingers and tighten them till i cant turn them, then give them another 1/2- 3/4 of a turn more. also, did you break the cam in correctly??? if you didnt, im betting you wiped a couple lobes off of it.



Re: Not running right
Wednesday, March 02, 2005 7:28 PM
Thats exactly how I adjusted the lash for the rockers. I had a reverse vacuum in the crankcase a few years back and I pulled that motor apart about 4 times in 6 months before I got all the bugs out. As far as the cam break-in I praying not. I had a lot of ignition gremlins so the motor has been cranked quite often before I got it running halfway decent. Since it is running somewhat I did my best to operate the engine in drive under load (approx. 2000- 2800rpm) for about 20 min.
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search