4.0 problem

[Ecomike]

You might look for a restriction that is backing up flow and overpressuring the fuel pump between the fuel rail and the pump, located before the test connection on the fuel rail, perhaps a crushed tube or bad hose.

Regarding part defects, where there is one, there are many!!!!, if it is factory defects.

I don't buy the low fuel, quarter tank story.

I do agree it's a good practice to refuel before it gets much past a 1/4 tank, but I regularly refuel at 3 to 5 gallons remaining, adding 16 to 18 gallons to the 21 gallon tank to fill it, with no problem.

 

[5-90]

You might look for a restriction that is backing up flow and overpressuring the fuel pump between the fuel rail and the pump, located before the test connection on the fuel rail, perhaps a crushed tube or bad hose.

Regarding part defects, where there is one, there are many!!!!, if it is factory defects.

I don't buy the low fuel, quarter tank story.

I do agree it's a good practice to refuel before it gets much past a 1/4 tank, but I regularly refuel at 3 to 5 gallons remaining, adding 16 to 18 gallons to the 21 gallon tank to fill it, with no problem.

I wasn't saying that consistently running below 1/4-tank would kill your fuel pump - if it did, I'd have replaced a lot more of them! Just that your pump will probably last longer if you keep the tank reasonably full. The pump itself is typically 4-6" tall, and sits upright an inch or two off the bottom of the tank. You'll want to keep the thing at least 2/3-submberged to help keep it cool (yes, it's less of a problem than it's usually made out to be, but it's still a useful practise) which means about 1/4-tank in most cases.

If you consistently run well under 1/4-tank - we're talking weeks at a time here - you're probably going to experience decreased longevity for your fuel pump (translation: you'll kill it quicker...) but even that is sketchy. As I said, it's just more a good practise than anything else to keep the pump "under water."

(And it's very true that bad parts can "run in batches." I've seen that before...)

 

[8Mud]

The shop can't get a whole assy. It was just a fuel pump. The assy is back ordered nation wide and they said it would take 2-3 months to get. I am going to clean my tank out and try a different brand of fuel pump. I tried to pump the gas a little and then hold it 1/8 down when it happened last time and it nothing happened. I checked the maintainance records the lady gave me when I bought it. The crank sensor was replaced in May 07 and the the distributor cap, wire , and plugs were changed at this time also. The check engine light came on when I turned on the ignition and then went out when I was having the problems.

All info is appreciated

Thanks

Just to cover all the bases. if the pump was jammed and started working after being jarred, the pump is likely bad.
The CEL should come on every time you turn the key to off then to run. If the CEL doesn't illuminate this can be an indication of a 5 volt sensor supply short someplace (likely the CPS or sync sensor). If the 5 volt sensor supply shorts the CEL often doesn't illuminate when the key is in run, a quirk of the system. And the pump relay won't close. except for the second or two it primes when the key is first turned to run then start. I have someone turn the key to run, while I hold my finger on the top of the pump relay. it will close for a second or two then open again (Prime), then it should close again when the key is truned to start. The click in the relay is subtle and hard to feel, it may take a few tries. I've actually jumped the relay and gone to the rear to listne for the pump, if the pump runs when the relay is jumped, it's likely a sensor problem. If it doesn't run it's a pump problem or a wiring problem.

Jump the 87 and 30 slots in the relay socket, but don't get it crossed up as this may be catastrophic. Using a fused jumper may be smart.


If all else fails, I had one pump that wasn't getting sufficient amperage, the volts were there. The connector behind the left rear panel was crispy and the pump power pin was barely making contact. It tested good for voltage but the pump was intermittent because of the low amperage. Drove me nuts.
The pump hoses for the 95 and 96 are a known trouble spot and deteriorate.

 

[higherelevation]

The CEL comes on when I turn the key to run position. I got a new fuel pum, filter, relay (as pictured above), and screen today. I just got it all in. I also drained the tank of all the old fuel and put fresh fuel in. I also put some water remover in there just incase. I turned the key a couple of times to get the fuel up there. It started right up. I have it running right now trying to get the old fuel out of the lines. I really hope this works. I don't have the money to keep putting in it.

Thanks for the help 8Mud. I am going to try and get my buddy to come over so I can check the relay also.

Thanks everyone for there input. If anyone has any other suggestions, please let me know. I will post soon with an update.

 

[Ecomike]

Don't forget to inspect the entire fuel line for a restriction that could over pressure the pump and burn it out. If there is an internally collapsed hose or piece of damaged tubing you could have very high pump pressure between the bad spot and the pump, but still read proper fuel presure at the fuel rail!!!!!:shiver:

 

[higherelevation]

I am going to blow the fuel line out today with my air compressor and replave the rubber fuel line just as a precaution. I have run it in the driveway and it has been good so far. Last night I ran it and found antifreeze on the ground so now I have to fix a leak on the radiator. I am going to try the radiator stop leak fluid since it is very small. I am kind of skeptical to drive it anywhere and turn it off. So I plan this weekend to take a couple of trips out and then bring it home and turn it off. I don't want to pay for anymore towing. I usually never run below a 1/4 tank on any of my vehicles. I appreciate everyones input. Thanks

 

[higherelevation]

I blew the metal fuel lines out and replaced the rubber fuel lines. I went and put gas in it today and the tank leaks from where I took the pump out. Is there a secret to get the gasket seal to line up?

Thanks

 

[higherelevation]

Drove it to work last night and when I came out 10 degrees it fired up. I got the tank seal to seat. Filled her up with fresh gas. Tonight it is -10 degrees again so I am hoping the gremlins are behind me now. I am hoping that the 2 pumps before this one were defective. Would like to thank everyone for their help and input.

Thanks