1985 Ford F-150 I'm burning up low pressure fuel pumps

Tiny
DUEYCRAVEN1
  • MEMBER
  • 1985 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 19,000 MILES
I have my 302 EFI at a reputable mechanic in town. He has done alot of work on it over the last few years. Lately truck will spit and sputter and eventually stall after driving long enough to obtain temperature. Let it sit for 30-40 minutes and it fires up and drives fine until it reaches temp again. Mechanic said fuel pump was bad in tank. We have now burnt up three of them in the last two days. The pumps motor will not even turn when hooked up to direct current outside of the tank. Same thing keeps happening. Any ideas? Suppose to take this truck to Daytona for the races this weekend. Please Help!
Tuesday, July 1st, 2008 AT 5:42 PM

8 Replies

Tiny
OBXAUTOMEDIC
  • MECHANIC
  • 3,711 POSTS
Ok, you said the intank pump was bad. Now I know on some of the early models there were 2 pumps one intank and one inline along the frame rail. If it has the second pump have it check. Check for damaged fuel lines and check the wiring harness.

Also have the coolant temp sensor checked. It can cause the problem as far as the spit and sputter and stalling when or shortly after reaching Temp.
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Tuesday, July 1st, 2008 AT 6:40 PM
Tiny
DUEYCRAVEN1
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The pump along the frame rail has been checked, and is fine. Where would I be able to find this coolant temp sensor? Why would the fuel pump not work even after being removed from the truck, and what would the coolant sensor have to do with ruining the fuel pump?
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Tuesday, July 1st, 2008 AT 6:53 PM
Tiny
AIRSOFTSOLDRECN9
  • MEMBER
  • 348 POSTS
Have you checked the fuel pump relay/fuse/circuit for proper voltage (particularly amperage while the pump is running)? Is the pressure regulator working correctly? The fuel lines are completely cleaned with no obstructions (this would include the second pump as you probably only have one fuel filter after it)?
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Tuesday, July 1st, 2008 AT 7:06 PM
Tiny
OBXAUTOMEDIC
  • MECHANIC
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It is located in or around the gooseneck going into the engine. The coolant sensor doesn't have anything to do with the fuel pump problem. I believe you have 2 seperate problems that just started about the same time.
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Tuesday, July 1st, 2008 AT 7:17 PM
Tiny
DUEYCRAVEN1
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  • 5 POSTS
Fuel lines, wiring harness, filter, fuel tank, and both pumps were replaced last June. I've put approximately 2000 miles on the truck since then. I used Stabil when it was parked, but still started it and ran it a few miles each month. What's funny is I can almost pinpoint when the problem will occur based on the temp gauge. I can go 25-30 miles on the open road during the day with no problems. It will stay running after that, if I can keep it up to speed. As soon as I let off the gas it stalls and will not re-fire until it cools down. At night it will go further without any trouble. I will talk to the mechanic in the morning regarding proper amperage and the pressure regulator. At first we were thinking thin film sensor, but it checks out o.K.
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Tuesday, July 1st, 2008 AT 9:20 PM
Tiny
DUEYCRAVEN1
  • MEMBER
  • 5 POSTS
It is located in or around the gooseneck going into the engine. The coolant sensor doesn't have anything to do with the fuel pump problem. I believe you have 2 seperate problems that just started about the same time.[/Quote:ba4dcc28e8]

Great. Just what I need, two problems. Why do you think the mechanic is reporting to me that the fuel pumps are shot but in the past when I have had the problem, all I had to do is let it cool down. Keep in mind the guy has not charged me anything for the fuel pump he replaced two weeks ago, thinking that was the problem, or the second and third he wasted today after he drained the fuel tank and started with fresh fuel, thinking maybe it was bad gas due to the truck sitting and the sock being yellow. We are both really frustrated.
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Tuesday, July 1st, 2008 AT 9:30 PM
Tiny
OBXAUTOMEDIC
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What you stated above is why I suggest getting the Coolant Temp Sensor checked. I had an 89 E150 with the 302 in it and had the problem of spitting and sputting then stalling shortly after reach opperating temp. I never got a Check Engine Light and No Codes. Had be befuddled, I called the Ford Dealer and they told me to change the Coolant Sensor well needless to say I didn't cause didn't quite trust them. Anyway about a week later the thing wouldn't start period. Well, I then went and got the coolant sensor and to my surprise is started after replacing it and had no more problems with the spitting, sputtering and stalling.

It could also be caused by the fuel pump overheating for some reason so check the items that airsoftsoldrecn9 has reccomended.
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Tuesday, July 1st, 2008 AT 10:22 PM
Tiny
PEAR69
  • MECHANIC
  • 1,482 POSTS
Make sure you have a good electrical connection where the fuel pump plugs into the wiring harness. OR just change the fuel pump wiring connector.
Sometimes when you unplug a electrical connector (especially a fuel pump electrical connector) and then plug it back in the connection becomes loose. This loose connection will cause an electrical arc -- this will heat up over a period of time -- causing the connection to intermittentley fail and stop the pump. This arcing also causes corrosion, so when the pump electrical connection cools down and the pump starts back up again, this corrosion causes exessive resistance in the connection, which will cause the pump to be supplied with less voltage than it needs. When any electrical motor is supplied less than operating voltage it will fail rapidly. CAUTION -- if you test the circuit at the fuel pump for the proper voltage, you will indeed have the proper voltage; because when you hook up electrical probes to the connector you will pierce through the arc corrosion -- this is a false reading. Also, make sure the fuel pumps' ground is not corroded -- this will do it too.

BTW -- hope you make the races and I hope you are cheering for the best driver at the speedway this weekend -- who just happens to be DAVE BLANEY ! That's right DAVE BLANEY ! Number 22 CAT CAR ! And "yes" I am a BLANIAC !
Anyway -- Enjoy the races.
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Tuesday, July 1st, 2008 AT 10:48 PM

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