The car is our 88 V6 origionally. We have converted a 1995 LT-1 to carbed and gotten rid of all electronics except windsheild wipers and chassis.

Everything works perfect except for the fact that it will not run worth a damn !!

The carb is a Holley 750, i'm running the mallory regulator using the stock 2.8 pump.

I can give the car a couple squirts, and it will start, run choppy as hell then die. If you give it gas, it will rev, then sputter and die. If you get it started and hold the vaccum secondaries open, it will run for about 30 seconds flawlessly.
I've caught the carb on fire twice and had some bad backfires Timing is correct, it's just this damn carb.

I have noticed I cannot get the float bowls to fill properly. I have to keep priming the pump. It seems to run long enough to drain the bowls or something. My brother thinks i'm not getting enough fuel, but I think i may be getting too much since it works fine with the secondaries opened a bit.

I cannot set the bowls properly apparently and maybe this is the problem.

Do I need to have the pump running all the time ?? Is it going to only prime and not work since it does not receive any info from the ECM like oil PSI ? Do I need to run it to the ignition fuse or something ?

I'm going nuts cause this is the only problem now and I'm tired of driving 3 hours each way every weekend to come to work on this thing while my wifes pissed cause she can't take her camaro any where due to me shoving this engine in it

-Shannon

 

I would say it definatly has to do with the fuel pump. I'm not sure about the ECM affecting it or not, but the engine isn't going to run right if the fuel bowls don't stay filled to the proper level.

 

Nomad, just hot wire the fuel pump to the battery,
(make sure your fuel presssure is correct for carbs)
that would narrow the range of possible problems.

 

contactpatch is right(kinda) you will have to use a fuse and a relay to make it safe. when the pump was used originaly it primed when you first turned the pump on and then waited for a signal from the ecu to turn the pump back on when it got a signal that the engine was turning.
also my car is simalar in size and setup and she likes 6.5 to 7psi on the presure regulator(track tested). i also hooked that relay to a switch instead of the key, personal preferance.

 

Hot-wiring the pump to the battery is a very bad idea. You don't want the pump running when the engine isn't.

Sounds like the initial switch-on priming function is working. Now you need to hook in a parallel oil pressure switch circuit powered from a switched source (not the ignition circuit, though).

 

thats not a bad idea but out of all the people who have electric fuel pumps id like to see how many people went through that complicated stuff and how many did like i did and wired it to a switch and turn it on and off when i need to.

 

In a crash, the pump will continue to run as long as it has power if its hooked up to a switch. With the ecm or the oil switch, the pump will stop running when the motor stops so if there is a problem and the lines are damaged the pump wont spray gas everywhere.

 

nvm...

 

You need to have a fuel pressure regulator if you are still using the electric pump.