Okay, I've been trying to tune my new 383 setup for months now. After tuning my VE tables, SA tables and adjusting them back and forth, I still get a very irratic idle, with huge variances of mixtures. I can find no vacuum leaks or anything obvious. When I have the laptop connected, the car can go extrememly lean or extrememly rich. I've already replaced the ECM from GM, checked all my connections, etc. I have the stock AFPR that came with my HSR. I had to adjust it in nearly the end to get my fuel pressure of 58 PSI for my 28.8 LS1 injectors but as far as I can tell, it's keeping it where I need the fuel pressure as I have a pressure gauge installed.

Could the AFPR be leaking? Could it be bleeding off too much? I was told AFPR's either work or they don't work and I'm looking for people who had a similar problem as I have before I go out and by a Kirban AFPR for $105.

Thanks for any help!

 

If you are using the one from Holley, you might want to replace it. I've heard alot of reports of bad AFPRs from them. When I was considering going HSR I had already made up my mind to go with the Kirban AFPR due to all the Holley horror stories.

 

After looking over the AFPR, I found out that the hose I had was causing a major vacuum leak. After replacing the hose going to the AFPR, it's running better now. I called Kirban and ordered one, but they had their AFPR's backordered. So I canceled my order for now. I'll probably get one later on.