Runs poor upon reaching operating temp
Installed a 400 Hp unit on big block Chevy. Had a junk Edelbrock Pro Flo Gen 1 on prior. New Mallory Unilite vacuum advance, new MSD 6A, new Mallory super coil. Once the truck reaches operating temp it acts like it is fuel starved. Runs great prior to reaching around 185. It either dies completely or won't accept any throttle. Talked to FITech and they walked me through adjusting the idle speed screws and said they were not in synch. No change.
Unk specs on cam or exact engine displacement. Seems like a moderate cam with a smooth idle. Once it cools down it runs fine. Good idle and no popping through throttle body upon acceleration. What am I missing here?
A few questions.
- What is your AFR when it acts like its fuel starved?
- What fuel pump make/model. I had similar issue with my mallory inline pump - more ambiant air temp related. When temps got into the 90s the fuel pump would overheat and starve the engine. I'm going in-tank.
Really need to know what your AFR is to see if it's fuel pump related.
AFR Trim and AFR Learn during issue?
Well I took the truck out and drove it. Had to drive it hard to get it to act up. With the temp at 199 it suddenly started running poorly. The AFR had been at 14.2 or so then went to 11.2 then up to 20.3 before dying completely.
The fuel pump is an inline Walbro GSL 392. Once it cooled down I was able to resstart it and the AFR went back to 14.2 or so.
Could it be an issue with fuel boiling? Are the intake manifold, fuel lines or EFI unit getting too hot?