So it finally happened after driving 2 T/A's 75k miles, my first fuel pump failure.Not really that big a deal, except that when I removed the return line, there was pressure from the tank. I'm not talking a little gas in the line, but actual pressure from the tank, spilling at least 1 gal or more before I could pinch the line off. My thoughts are a split hose at the pump(electric in tank), or a clogged tank vent. Any one have any other ideas?

 

When you turn the key to the on position, do you hear the pump prime? for 2 seconds?

 

Yes it does, and will start and run for a moment and then stall. After stalling there is no fuel in the rail...none zero nadda. I know its a fuel pressure issue,no doubt, but is it pump failure, split hose at the pump in the tank or both...I'm not sure yet( tank will be out by tomorrow morning). Not really the issuse,at 105k its getting a pump(TRE highvolume,255lph)strainer, filter and relay. The concern is why the tank had enough pressure to flow enough gas out of the return to run a carb'ed 350. This the return line from the engine which should have little or no pressure with the engine off and def not that line coming out of the tank...it's only purpose is to allow extra fuel from the rail go back to the tank. One last thought though, is it possible for the regulator to stick open and allow all the fuel pressure to flow back to the tank?Hum, maybe I'll more parts, i.e. adjustable regulator for a HSR.

 

If it primes but wont run with the motor running, check out the Fuel Pump Relay. You can put in a jumper at the ecm to turn the pump on all the time to rule out the pump. Check a chiltons manual but I think its like terminal H to power and the pump comes on. I have done this before but its been awhile. If the ca runs fine now its probably the relay but I think the oil pressure switch at the filte can cause this to.

Just a thought, whn I removed the return line on my car the car was on jacks in the back which raised the tank above the line and gravity spilled a few gallons out for me.

 

Well I got the fuel pump in this morning. The car now runs, but has a bad miss at idle, the converters rattle terribly andno power when driving. The fuel tank vent was clogged...but obviously not the problem. I gues my next step isnew plugs and converters, then test the mass airflow and dist. I also hooked up a fuel pressure gauge and only had 35 psi and when i pinched the return line it stalled the engine when it hit 75 psi. Guess i'll be calling holley to see if they will warranty it.

One last note...the car was on a lift at work for the pump install, so no gravity siphon on the vent line. I work for VW and have worked on cars for about 13yrs...so I've been lucky enough to get breaks on towing, parts and have all the latest tools and repair info.

 

Finally found the cause for the miss. After new plugs, fresh gas and a short test drive the miss was still at was still there, but the car had good power once into the rpm's. I happen to notice some moisture on the vac hose for the press regulator and with further inspection found that the regulator was leaking fuel through the vac port. Installed a kirban afpr today and it runs good except for the rattling cats.

 

where is the fuel pump relay?? and what is its function?

 

The relay is near the brake booster, and in a nutshell supplies power to the fuel pump. My advise is if you replace the pump, do the relay also...its a common cause of pump failure in may GM vehicles.