Chimera96

....what I and Fred have suggested is put a actual FP gauge on the Schrader valve to check what FP is.

Your "test" method of pushing in Schrader after car sits for 6 hrs and having zero fuel come out is not a confirmation pump is bad (it bleeds off)....and when you say you do KOEO the Fuel does come out the Schrader valve...which indicates the pump works

Sooo what you need to do is confirm "if" pressure is in spec.

or roll the dice and throw in a new fuel pump and see if it resolves your problem....our suggestion was to first confirm if that is necessary by checking FP with a "gauge"

Injuneer

Apparently you didn't read (or perhaps didn't understand) what I wrote in post #3. I listed 4 possible reasons for loss of fuel pressure when the pump shuts off. Only one of those reasons involved the pump.

But, I'll stop annoying you. You can play "parts replacement roulette", and you might have bet on the right cause. Good luck.

rc1980

So I'm at O'Reilly's put a fuel pressure gauge on the Schrader valve turn the key forward pressure goes up to 40 pounds and then drops down below 20

bw_hunter

Engine running or not? Vacuum line removed from regulator or not?

rc1980

Engine off. Didn't touch vacuum line

bw_hunter

Start the engine and let it idle. Remove and block the vacuum line from the regulator. Fuel Pressure should be about 43.5psi

Reattach the vacuum line, pressure should be lower based on the pressure difference between the atmosphere and the manifold.

rc1980

I would try that but now car won't start. Where is regulator and vacuum line located

bw_hunter

The regulator is on the back of the fuel rail on the driver's side. Here's a link to Rob's page for your viewing pleasure: http://shbox.com/1/fp_reg.jpg

Chimera96

with KOEO the 40 PSI is "normal" with vac line connected to FPR. Your fuel pump is bleeding off which is why the FP drops as it only "primes" when you turn KOEO (pump only runs a few seconds with KOEO)

What you want to do is have FP gauge hooked up with engine "running". It should be around 35-37 with vac line on (43.5 vac line off and plugged). Rev the motor some, FP should come up a few PSI...if it nose dives than the pump is failing.

Your brief test does indicate the Fuel Pump does prime within spec...and now that car does not start, assuming you still have fuel pressure, than your issue is elsewhere (ignition)

IMHO having a FP gauge in your tool box with a hose on it so you can tape the gauge to windshield and monitor temporarily to see how FP is during "driving", especially sustained WOT, is a good idea to rule in/out fuel supply issues.

rc1980

And I get that. Makes since. However, with fp gauge on the car and turning key forward to run while engine off shouldn't the pressure hold and not drop down to 10lbs?

rc1980

I also read on another site that the solenoid on the starter gets to hot and keeps car from starting. And there are times when I will crank and get the 1 solid click from starter like it's froze up, but when I keep trying starter starts cranking normally. The reason fuel pump makes since to me is that the car sat for 2 years with the same gas in it and the fact that it doesn't hold res pressure. Thanks man.

rc1980

And just to add another side note. When car starts and I'm driving it, I will run the hell out of it 80 90 mph and the car never acts like it's starving for gas, that part has me scratching my head....

Chimera96

Fuel Pump can be "intermittent" but given you do full 80-90 mph blasts with no engine stumble that indicated pressure (pump) is good.

2 years sitting with gas didn't help anything. replace the fuel filter if you have not

the starter thing....heat and starters don't get along. completely separate issue than fuel pressure and with that 411 worth looking into starter or cables/wiring to it if you have experience clicking and no start then after several key trys it starts

rc1980

Where is fuel filter located? What is your thought on the res pressure?

Chimera96

this site is VERY helpful...has part locations

shbox.com

the pressure bleed off of the fuel pump happens. Ideally it would hold longer than yours does. my walbro 255 pump has never held pressure long after the key is off.

Soooo this is why having the FP gauge on while engine running, especially under driving conditions, will show if pressure drops under use/load. If it does than pump is failing. The fact pump bleeds off is not a indication it is "bad". The test is if pressure is sustained under use, not just testing it with engine not running