Random fuel shut-off while driving.

[Jason.Silus]

I own a '96 4.6L, and for the last year, it's broken down several times from seemingly the same cause. While driving, it will sputter out and die, and then by the next morning, it'll start right up again. After trying to diagnose it myself for about a month, I took it to the shop. They replaced the fuel pump and water pump (I had been having overheating issues at the time as well). I drove it for a while, and it died again. I discovered a leak in the gas tank where the sending unit sits, so I tightened the locking ring, and it stopped the leaking, however it died about 2 weeks later. Took it back to the shop. They replaced the electrical connectors that had probably been there since '96, and got new brakes while I was at it. I drove it to school and it died on the way back. I'm at a loss at this point. I've checked all of the relays, the fuel pump and sending unit have been replaced, and the shop refuses to take another look at it. What would cause a random fuel pressure shut-off like the one I'm getting?

Edit: Forgot to add, the starter does turnover the motor, it has compression, air, and spark. The problem is 100% fuel.

Car details:
1996 4.6L 2v GT
200,000 Miles
Convertible

 

[RAU03MACH]

Intermittent problems are the worst especially electrical , while its running start tugging on all the wire harness and connectors
also check all grounds , i would start there , unplug the computer , plug back in , next .

 

[lwarrior1016]

Did they replace the wiring harness on top of the tank?

 

[ttocs]

I will assume if they replaced the pump they did the filter but it was not mentioned above. Are the injectors original? I have found problems on my car that were caused by the fact the harnesses were old and when they got hot they would not make solid contact and eventually cause problems.

 

[Jason.Silus]

Did they replace the wiring harness on top of the tank?

Yes the harness was replaced, as well as the fuel filter.

 

[Jason.Silus]

I will assume if they replaced the pump they did the filter but it was not mentioned above. Are the injectors original? I have found problems on my car that were caused by the fact the harnesses were old and when they got hot they would not make solid contact and eventually cause problems.

As far as I know, the injectors are original. The wiring harness was replaced because the original one looked like somebody had shot it with a laser.

 

[ttocs]

I hate to throw parts at a problem to see if it helps but if the injectors are original it would not be a horrible idea to try a new set.

 

[lwarrior1016]

Is there any way you could put a fuel pressure gauge on the rail and watch it while driving. See what it does when it starts to die?

 

[Jason.Silus]

Is there any way you could put a fuel pressure gauge on the rail and watch it while driving. See what it does when it starts to die?

I've never set something like that up, but it's on my list of mods. I guess rn would be a good time to do it. I'll order some parts and get to work and come back to this with my results.

 

[Monday]

MAF

 

[Monday]

MAF

MAF

 

[Jason.Silus]

MAF

I assume you're talking about the mass airflow sensor? It works just fine, I've tested it while it's running and when it dies.

 

[Monday]

I assume you're talking about the mass airflow sensor? It works just fine, I've tested it while it's running and when it dies.

Yes. You've pulled it off running?

 

[Monday]

oh yeah! forgot to mention your iac and pcv as well

 

[07GtS197]

Have you replaced the fuel pump relay? It could be opening the circuit when it gets hot. Or the ccrm could be suspect too. I’m with lwarrior though, check the fuel pressure when it’s running and when it dies.

 

[Jason.Silus]

I've never set something like that up, but it's on my list of mods. I guess rn would be a good time to do it. I'll order some parts and get to work and come back to this with my results.

I'm getting a fuel pressure guage soon, but I wanted to try and start the car today and this happened. Similar problem as usual, car acts like it's out of gas even though it isn't. I figured want to get a fuel pressure gauge in line, but I've begun to think I put too much faith in the shop that installed the fuel pump, and they did it incorrectly.
Edit: Having trouble uploading video

 

[ttocs]

try priming the fuel line 2 times. Turn the key on to run and wait for 5 secs(do not start it). Then turn the key off and right back to on for another 5 secs and then start it. See if the added fuel/pressure helps

 

[Jason.Silus]

try priming the fuel line 2 times. Turn the key on to run and wait for 5 secs(do not start it). Then turn the key off and right back to on for another 5 secs and then start it. See if the added fuel/pressure helps

Have tried this before. As I can hear the relay click and the fuel pump prime when turning the key into the run position, even when it's dead. The circuit for the fuel pump seems to work fine.

 

[Jason.Silus]

I'm getting a fuel pressure guage soon, but I wanted to try and start the car today and this happened. Similar problem as usual, car acts like it's out of gas even though it isn't. I figured want to get a fuel pressure gauge in line, but I've begun to think I put too much faith in the shop that installed the fuel pump, and they did it incorrectly.
Edit: Having trouble uploading video

 

[ttocs]

Have tried this before. As I can hear the relay click and the fuel pump prime when turning the key into the run position, even when it's dead. The circuit for the fuel pump seems to work fine.

this test was to see if there was some kind of supply issue. Sometimes charging the line 2x will give enough fuel pressure for it to fire and show that there is an issue.