Skip the auto shop - Our mechanics make house calls

Q: 1993 Ford F150 4.9 straight 6 fuel pump keeps running, won't start, replaced relay and fuel pressure regulator, still having the same problem

asked by on

Fuel pump comes on then cuts off. Truck starts then stalls. Fuel pump is running constantly. Won't let truck start sometimes if I wait a few minutes. Pump will stop and truck will run. It started this about a year ago then after a couple days, it stopped for about 4 or 5 months and then it started again and after a couple days it stopped and is getting progressively worse. I've replaced relay and the fuel pressure regulator, both did not help

Hi, thanks for writing in. You need to have the fuel pressure checked to see if the pressure is low. The fuel pump inlet screen may be getting clogged causing the pressure to drop off but the pump will continue to run. You may need to replace the pump if it is not producing enough pressure. If you have dual tanks then you may have a defective switching valve in center of vehicle on frame. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to test the system for you, and make or suggest any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  • Home
  • Questions
  • 1993 Ford F150 4.9 straight 6 fuel pump keeps running, won't start, replaced relay and fuel pressure regulator, still having the same problem

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: 67 mustang was finicky about starting so I replaced alternator and fuel pump but now it won't start

You seem to be indicating that the starter motor turns but the pinion gear is not engaging the flywheel. That means the pinion gear throwout assembly has a fault. You could try disassembling the starter to diagnose that issue or...

Q: Uncontrollable shaking

Hello and thanks for writing in. Shaking at high speeds is often times related to tires that may be out of balance, low on air, potentially a badly aligned front end or failing suspension components or ball joints. When any...

Q: Where are fuel & primer reset buttons?

Hello. The fuel pump reset button is located under the instrument panel, to the right of the transmission hump. I do not believe that there is a primer button on your vehicle. The fuel pump reset button is also known...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...