fuel system failure
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
fuel system failure
Good afternoon to all. Hope you can help. Not getting much drive time in my '96 LT1.
For some reason after driving a few miles.. (last time was about 30), the car dies and will not start for a few days. when this happens, the fuel pump shuts down...but.... as it sits in my garage for a few days... way past time period of just having to "cool off".. it starts and runs great until the next episode of dying and forcing me to hire a roll back tow truck to take us home.... any suggestions? right now the car runs fine but I don't want to drive it 'cause I'm confident it will die again.
Thanks,
Jeff
For some reason after driving a few miles.. (last time was about 30), the car dies and will not start for a few days. when this happens, the fuel pump shuts down...but.... as it sits in my garage for a few days... way past time period of just having to "cool off".. it starts and runs great until the next episode of dying and forcing me to hire a roll back tow truck to take us home.... any suggestions? right now the car runs fine but I don't want to drive it 'cause I'm confident it will die again.
Thanks,
Jeff
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Might be a bad fuel pump.
I would start hanging a fuel gauge on it and watching the pressure. Might also measure the voltage to the pump when it dies.
You cant fix it if it is working. You are going to have to make the problem happen at home so you can work on it and find the cause.
I would start hanging a fuel gauge on it and watching the pressure. Might also measure the voltage to the pump when it dies.
You cant fix it if it is working. You are going to have to make the problem happen at home so you can work on it and find the cause.
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
Ya,.. that's one of my problems... I have tried to leave it running at my house for a couple hours and it will not die. It's a gamble whether it will die when I drive it. Never heard of a fuel pump fail then eroneously come back to life. But,.. when it does die, It's definately not pumping fuel. Just don't know if it's electrical system or what. Can relay's short or get hot and fail,.. then come back to life?
this Trouble started after I ran the car through a car wash and opted for the undercarriage spray. died that day,.. started the next and ever since then I have this mystery. I initally thought it was that the opti got wet and then dried out but it is definately a fuel problem. When it dies I can take off the fitting on the fuel rail and it is pumping nothing and no sound coming from the pump. Then,.. couple days later, it may start and run great
this Trouble started after I ran the car through a car wash and opted for the undercarriage spray. died that day,.. started the next and ever since then I have this mystery. I initally thought it was that the opti got wet and then dried out but it is definately a fuel problem. When it dies I can take off the fitting on the fuel rail and it is pumping nothing and no sound coming from the pump. Then,.. couple days later, it may start and run great
Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
Ya,.. that's one of my problems... I have tried to leave it running at my house for a couple hours and it will not die. It's a gamble whether it will die when I drive it. Never heard of a fuel pump fail then eroneously come back to life. But,.. when it does die, It's definately not pumping fuel. Just don't know if it's electrical system or what. Can relay's short or get hot and fail,.. then come back to life?
this Trouble started after I ran the car through a car wash and opted for the undercarriage spray. died that day,.. started the next and ever since then I have this mystery. I initally thought it was that the opti got wet and then dried out but it is definately a fuel problem. When it dies I can take off the fitting on the fuel rail and it is pumping nothing and no sound coming from the pump. Then,.. couple days later, it may start and run great
this Trouble started after I ran the car through a car wash and opted for the undercarriage spray. died that day,.. started the next and ever since then I have this mystery. I initally thought it was that the opti got wet and then dried out but it is definately a fuel problem. When it dies I can take off the fitting on the fuel rail and it is pumping nothing and no sound coming from the pump. Then,.. couple days later, it may start and run great
and hook it up to your schrader valve. Tape the gauge to your windshild and drive. Fuel pump/clogged up fuel filter?
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
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From: Wichita Ks.
K. Thanks I will try that and see what kind of pressure I have. The car runs good and strong though right up until it dies. Thanks for the input. I will keep you posted on results of pressure test
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
well,.. it get's spark. When it was dead, I could spray a starting fliud in and it would run as long as I was spraying. And when I open the valve on the fuel rail No fuel is spitting out when I turn the engine over.
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Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
With an intermittent failure, all you can do is guess.
If it were my car, I would replace the relay and the pump and be done with it. Especially if I had been towed home. Cheaper than tow trucks.
If it were my car, I would replace the relay and the pump and be done with it. Especially if I had been towed home. Cheaper than tow trucks.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
Please explain this leap of logic.
I can not tell you the number of times that folks come on here with problems, get advice, and are never heard from again with no feedback.
I am not singling out the OP but give some feedback. Did you fix it? Did the advice work? Did you give up?
I can not tell you the number of times that folks come on here with problems, get advice, and are never heard from again with no feedback.
I am not singling out the OP but give some feedback. Did you fix it? Did the advice work? Did you give up?
Last edited by MK 82; Nov 8, 2009 at 07:58 PM.
Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
Please explain this leap of logic.
I can not tell you the number of times that folks come on here with problems, get advice, and are never heard from again with no feedback.
I am not singling out the OP but give some feedback. Did you fix it? Did the advice work? Did you give up?
I can not tell you the number of times that folks come on here with problems, get advice, and are never heard from again with no feedback.
I am not singling out the OP but give some feedback. Did you fix it? Did the advice work? Did you give up?
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
?? not sure what the opti comment and not giving feedback is about?....
I don't think it's the opti. as I stated before, it get's good spark just no fuel at the rail/shrader valve when it's dead. But later as the car sits for more than a couple days it will run.
I hooked up a fuel guage but had to rig it so not sure how accurate it is. Shows 30 psi while the car is running. But like I said,,. rigged. I did not have the correct fittings so I used an air conditioning fitting that would screw on and push in on the valve. However,.. it would not push the valve open enough so I put a BB in there. pushes it open now but may be restricting some fuel flow to the gauge. like I said.. "rigged".
I did change the fuel filter and the pressure did not raise. At one point when the car was chugging a little bit, there was a clicking going on what sounded like inside the dash area. I was sitting in the car and it could have been coming from the firewall. soon as the clicking stopped the car smoothed out again.
I don't think it's the opti. as I stated before, it get's good spark just no fuel at the rail/shrader valve when it's dead. But later as the car sits for more than a couple days it will run.
I hooked up a fuel guage but had to rig it so not sure how accurate it is. Shows 30 psi while the car is running. But like I said,,. rigged. I did not have the correct fittings so I used an air conditioning fitting that would screw on and push in on the valve. However,.. it would not push the valve open enough so I put a BB in there. pushes it open now but may be restricting some fuel flow to the gauge. like I said.. "rigged".
I did change the fuel filter and the pressure did not raise. At one point when the car was chugging a little bit, there was a clicking going on what sounded like inside the dash area. I was sitting in the car and it could have been coming from the firewall. soon as the clicking stopped the car smoothed out again.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
The opti remark wasn't aimed at you.
As I understand it, the car fails to start for days with no fuel pressure. Right?
If so, that is when you must troubleshoot. The clicking could have been the fuel pressure relay.
As I said earlier, I would change the pump and relay. It may not be both but you have no way of narrowing it down any more with an intermittent failure.
Fuel press gauges are not expensive.
My rant about folks disappearing was not necessarily aimed at you. It was for the folks who post a problem, get advice, and disappear.
As I understand it, the car fails to start for days with no fuel pressure. Right?
If so, that is when you must troubleshoot. The clicking could have been the fuel pressure relay.
As I said earlier, I would change the pump and relay. It may not be both but you have no way of narrowing it down any more with an intermittent failure.
Fuel press gauges are not expensive.
My rant about folks disappearing was not necessarily aimed at you. It was for the folks who post a problem, get advice, and disappear.
?? not sure what the opti comment and not giving feedback is about?....
I don't think it's the opti. as I stated before, it get's good spark just no fuel at the rail/shrader valve when it's dead. But later as the car sits for more than a couple days it will run.
I hooked up a fuel guage but had to rig it so not sure how accurate it is. Shows 30 psi while the car is running. But like I said,,. rigged. I did not have the correct fittings so I used an air conditioning fitting that would screw on and push in on the valve. However,.. it would not push the valve open enough so I put a BB in there. pushes it open now but may be restricting some fuel flow to the gauge. like I said.. "rigged".
I did change the fuel filter and the pressure did not raise. At one point when the car was chugging a little bit, there was a clicking going on what sounded like inside the dash area. I was sitting in the car and it could have been coming from the firewall. soon as the clicking stopped the car smoothed out again.
I don't think it's the opti. as I stated before, it get's good spark just no fuel at the rail/shrader valve when it's dead. But later as the car sits for more than a couple days it will run.
I hooked up a fuel guage but had to rig it so not sure how accurate it is. Shows 30 psi while the car is running. But like I said,,. rigged. I did not have the correct fittings so I used an air conditioning fitting that would screw on and push in on the valve. However,.. it would not push the valve open enough so I put a BB in there. pushes it open now but may be restricting some fuel flow to the gauge. like I said.. "rigged".
I did change the fuel filter and the pressure did not raise. At one point when the car was chugging a little bit, there was a clicking going on what sounded like inside the dash area. I was sitting in the car and it could have been coming from the firewall. soon as the clicking stopped the car smoothed out again.
Last edited by MK 82; Nov 9, 2009 at 01:05 PM.
Race Director
Joined: Jun 2009
Posts: 10,428
Likes: 9
From: Southside of Western Norte Americano State of Confusion, ColoFornia
St. Jude '13
I dont know a lot about the 90-ish cars but it sounds like the relay clicking behind the dash is the clue.. do theses cars have the same type oil pressure cutoff to the fuel pump that the 85s have?? Because all of this sounds like a vibration condition.. sitting in the Driveway it wont die.. that would tend to rule out the pump overheating.. as idling in the drive is the best way to heat soak the pump.. no airflow and low volume.. but if your driving.. add vibration to the equation.. and the relay triggering would make me think the relay is working but what sends the signal to the relay is where the false signal comes from..I.E. a loose wire on the oil pump switch or engine ground.. wiring to the relay.. i would fire it up and wiggle those points in the wiring trying to duplicate the issue.
Just guessing, hope it helps in some way.
Just guessing, hope it helps in some way.
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
Thanks, this is kinda along the train of thought line I was on. If you read from the start of the thread, the trouble started right after I left the car wash and did the undercarriage jet spray.(as soon as I pulled out from the wash it died) I think I knocked a wire loose or something,.. but cannot find it and the book I have does not depict the location of even the fuel pump relay..or oil pump switch. It shows pics from cars in the 80's
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
Good afternoon to all. Hope you can help. Not getting much drive time in my '96 LT1.
For some reason after driving a few miles.. (last time was about 30), the car dies and will not start for a few days. when this happens, the fuel pump shuts down...but.... as it sits in my garage for a few days... way past time period of just having to "cool off".. it starts and runs great until the next episode of dying and forcing me to hire a roll back tow truck to take us home.... any suggestions? right now the car runs fine but I don't want to drive it 'cause I'm confident it will die again.
Thanks,
Jeff
For some reason after driving a few miles.. (last time was about 30), the car dies and will not start for a few days. when this happens, the fuel pump shuts down...but.... as it sits in my garage for a few days... way past time period of just having to "cool off".. it starts and runs great until the next episode of dying and forcing me to hire a roll back tow truck to take us home.... any suggestions? right now the car runs fine but I don't want to drive it 'cause I'm confident it will die again.
Thanks,
Jeff
Advanced
Joined: Jul 2007
Posts: 91
Likes: 0
From: North Middlesex MA
FWIW, and it may not be worth much -
I went crazy chasing a ghost on our 88 this past spring. Intermittent fuel problem. I'd run through specifics but I'm sure the operating principles and debug order are different by 96.
Our problem was an intermittent open at the bulkhead connector where the harness passes into the tank, found thanks to another 88 owner who had the same problem. Pull the rubber boot out of the filler so it's accessible. Next time it fails, probe for power at the filler and if there's power but no pump running, try giving the bulkhead connector a sharp rap with the back end of a screwdriver. For me it was a desperation move but it proved the problem.
Good luck,
- Jeff
I went crazy chasing a ghost on our 88 this past spring. Intermittent fuel problem. I'd run through specifics but I'm sure the operating principles and debug order are different by 96.
Our problem was an intermittent open at the bulkhead connector where the harness passes into the tank, found thanks to another 88 owner who had the same problem. Pull the rubber boot out of the filler so it's accessible. Next time it fails, probe for power at the filler and if there's power but no pump running, try giving the bulkhead connector a sharp rap with the back end of a screwdriver. For me it was a desperation move but it proved the problem.
Good luck,
- Jeff
Thread Starter
Intermediate
Joined: Feb 2009
Posts: 44
Likes: 0
From: Wichita Ks.
Back to the no fuel pump running problem,..
Hey Guys,.. I had to leave on business for a few months now I'm back and really want to get this car going! I have a couple of manuals but none show me where the fuel relay switch is located on the car. As in a previous post, I noted a clicking from what sounded like under the dash or perhaps on the firewall.. (I was sitting in the car when I heard it). Can anyone please give me a good description or diagram of where to find the fuel pump relay and oil pump switch? Would be greatly appreciated.
Thanks,
Jeff
Thanks,
Jeff