IROCU2

I can turn my key to the on position and the I hear the fuel pump priming. However, when it stops priming the pressure goes from 40 to 0. I put a fuel pressure gauge on it and that's how I found this out. I just put a new fuel pump in during the summer so I don't think that's the problem. I am stumped. Need help figuring this one out. Thanks guys.

OrangeBird

iTrader: (1)

If the check valve truly is good in the new pump , and you don't have any fuel puddles under the car , the final two suspects would be the either the fuel pressure regulator or an injector (or injectors) are leaking .

sofakingdom

iTrader: (1)

Regulator isn't too much $$$... you could shoot one of those at it, and if it still does it, … you do the math.

"New" doesn't count for very much when something doesn't work.

IROCU2

Thanks guys I will give those suggestions a try. I am going to drop the tank to make sure that I did in fact tighten up the hoses. Just to rule that out. I will never know if I don't do it.

GeneralDisorder

iTrader: (1)

Most modern pumps don't have check valves and it's not critical that the system holds pressure. It may require slightly more cranking but once the engine is running it will be fine. There is no functional need for the system to remain completely pressurized after shutdown except to facilitate slightly more rapid starts.

GD

Vader

If the pressure regulator is suspected of leaking through, the fuel return line can be blocked off/pinched to test that theory.

FRMULA88

loose or bad gas cap.?? don't overlook the obvious

OrangeBird

iTrader: (1)

If the OP had a pump with the proper check valve , and if the rest of the system (fuel lines/fuel filter , regulator , and injectors) were able to hold pressure properly , in other words a system functioning "as designed" , I see no way how even totally removing the gas cap could possibly depressurize the fuel rail .......

GeneralDisorder

iTrader: (1)

Agreed. Gas cap has zero effect. I don't even run a vent valve on my car so my tank is atmospheric vented all the time.

Also I have no check valve. Doesn't affect operation. Running pressure is what's important.

We should take a few steps back here. What prompted the pressure check in the first place that shed light on this "non problem"? What are you trying to solve here? Because I'm 99.9% sure that "fixing" the bleed down after shut off (which can be difficult with these style regulators at this age), isn't going to effect the changes you desire.

Please tell us the "problem" so we can help you solve it. This symptom diagnosis isn't going anywhere I can assure you.

GD

OrangeBird

iTrader: (1)

I liked this post because the General asked the obvious question that I and the rest of the respondents missed ; What exactly IS the problem with the car that prompted the fuel pressure leakdown check ?

BIRD91ZRAG

iTrader: (1)

Probably extended crank time. My 87 TPI car would pump up to 45ish psi, then once the pump kicked off, it held around 39 psi. Makes starting much easier.
When the pump was going bad in my 2000 truck, I would have to turn the key on/off 2-3 times, then it would start right away. Otherwise it was about 20 seconds of cranking to get enough pressure at the injectors to run the engine. LS engines take 55 psi or so though..

IROCU2

One day I went to start my car and it would not fire up. It turned over but never started. So I thought that my fuel pump was bad and I ordered a new one. i drop the tank and installed the new one filled with gas and tried to start it to avail. I hook up my fuel pressure gauge and I was not getting and fuel pressure. I finally got it to get fuel pressure and now when it primes after the 2 seconds the fuel pressure drops to zero.Then I yes I over thought the situation and replaced my distributor with new spark plug and wires. But I was able to put everything back ti TDC and it is getting spark just not starting.

GeneralDisorder

iTrader: (1)

You're problem is not the pressure drop. Keep troubleshooting.

GD

sofakingdom

iTrader: (1)

The pressure drop won't cause a no-start. Might cause other things, but not that.

You sure you put the dist in with the engine at the instance of #1 TDC that's #1 firing and #6 crossing from the exh stroke to the int; and NOT #6 firing and #1 crossing over?

Does the rotor point to the #1 plug terminal when the engine is at #1 firing?

IROCU2

Sofaking I am sure I got the distributor installed right. Why would the fuel pressure drop and not hold at the end of the 2 second priming time?

GeneralDisorder

iTrader: (1)

We have already been through the diagnostics for that. Bad/No check valve at the pump, bad pressure regulator, or leaking injectors. That's the ONLY possibilities. MOST aftermarket pumps (including the one's in BOTH of my cars) have no check valve and thus bleed down rapidly when not running. It has ZERO effect on them running. This IS NOT your issue. Is that clear enough? You need to get past being stuck on this. It's only making your problems worse by giving you tunnel vision.

In any case as long as it pumps up to 43.5 or close to it, it doesn't matter if it drops off when the pump turns off. If it builds pressure while it's running/cranking then it's not the cause of your no-start.

GD

IROCU2

General thanks for the help. I do need to get pass my tunnel vision. lol I will keep trouble shooting to figure out what the problem is.

sofakingdom

iTrader: (1)

Good.

Start by VERIFYING - not "assuming", not "remembering", not "being sure", NOT NOT NOT NOT NOT NOT NOT NOT NOT - VERIFYING that the dist is installed correctly, as follows:

Remove the #1 plug; have your assistant BUMP the starter over in small increments until you feel compression - NOT looking at the timing mark; LOOK PHYSICALLY into the spark plug hole while your assistant continues to BUMP the starter over in small increments until you SEE the piston approach TDC; observe the dist rotor. VERIFY BY PHYSICALLY LOOKING AT IT that it points to the #1 spark plug terminal. Which if you stabbed it into the block correctly, will be at the front, slightly to the driver's side of directly ahead. The rotor should point maybe just a scoche over toward the driver's side from there. Put the cap back on, VERIFY that the plug wires are on in the correct order: 18436572 clockwise. Attempt to start the car.

If the dist is NOT pointed in the correct direction, take it out; drop it back in with the rotor pointing about 30° toward the front from straight toward the driver's side; drop it into the block, during which exercise the rotor will rotate clockwise about 30°; if it doesn't drop all the way down, hold it down GENTLY while your assistant BUMPS the starter over in small increments until it does; tighten the bolt; re-find #1 firing by FIRST locating its compression stroke and OBSERVING the piston.

Once you are POSITIVE the motor is at #1 TDC on the firing stroke and the rotor is pointed slightly to the driver's side of straight ahead, rotate the dist body until the signal-level connectors on the base are toward the driver's side; while pulling upwards on the rotor, line up the teeth of the little star things until they are "touching"; tighten the clamp until you can JUST BARELY still turn the dist body.

FULLY REASSEMBLE and start the car.

If everything checks out but it STILL doesn't start, come on back, and we'll take the next step.

Gunter278

I was driving my truck and it died. I thought it had ran out of gas my gauge doesn't work. A friend helped me and we have tried several fuel pumps. U can hear fuel pump kick in but its not getting gas.
please help. I'm at a loss what to do next.

Vader

Welcome Aboard!

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Although you may never find a more dedicated and technically qualified group of members gathered in one place on the internet as it is here, it may be best to locate a forum more related to the vehicle in question to get the best possible feedback and assistance.