New to the forum, but I'm in desperate need of help. I just replaced the motor in my 1994 z28 ( the engine ran fine before but developed a rod knock). after replacing the engine, the car will only start with the throttle at half open, and when it does start, I can feel the iac searching for a spot where it will idle, but it wont idle. I have to vary the angle of the throttle in order to keep it running. makes me think its running rich (dont know why), or not getting proper spark (checked every cylinder and its fine. the only things after market are my flowmaster exhaust and high volume fuel pump (i got plans). any input would be appreciated.

 

Have you checked for vacuum leaks. LF

 

I highly suggest if you are going to be replacing engines and doing additional mods, you must get datalogging capability. If you had this, you would know almost immediately what the problem is.

However, saying that, I think vac leak also.

 

Have you checked the fuel pressure?

 

double checked all of the vacuum fittings and i rtved the hell out of it when i was putting the intake on. havent checked fuel pressure. could i have blown the regulator? Ive adjusted rockers and replaced plugs and wires. no change. today Im buying a fuel pressure guage, checking that and compression. what would I need for datalogging?