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[wiljoe765]

I bought a 69 Camaro in March with a Big block motor and a FAST fuel injection setup. Car also has Vintage AC. The problem is when using AC the car wil lose fuel pressure as indicated on the hand held display and die. Coolant temperature runs 200-210. If I let it set and cool for about 20 min. it starts and runs fine without AC. What am I looking for? Thanks

[cook_dw]

What am I looking for? Thanks

Hopefully the phone number to FAST to see if they have any suggestions.  I would start with looking at the wiring.  If you don't feel comfortable with messing with it then I would suggest seeking out a reputable shop in your area.

[JKZ27]

Sounds like the A/C system and/or fans is robbing power from the fuel pump. Make sure there is adequate sized wire for each of the circuits, possibly from circuit breakers or a separate fuse block close to the battery. I guess those are the first things I'd check.

[69Z28-RS]

If he is using electric fans on a VA system they can pull a LOT of current; more than probably a 37A alternator can put out!
The FI pump probably draws a bit as well, so that would be my guess as well...

[KevinW]

I had a similar problem with amps using an original 37A alt and a big stereo.  Running the stereo would drain the battery at idle an low speeds, because the alt is not putting out many amps at low speeds.  I took my alt to a local rebuilder and they install 100A guts in my original case. That fixed the issue!

[wiljoe765]

Not using electric fans. Seems to be heat related. Are there any safety shut downs in this system?

[Charley]

What fuel pump and where is it located ?

[wiljoe765]

Pump is in the tank. Don’t know much about it. I moved a fuel pump relay in the harness away from the exhaust yesterday then drove the car with AC on for about 30 miles and had no problems. I’m hopeful that this is the cure.