Q: No start, lack of power to fuel pump

asked by on

My truck just died while driving, towed it home and installed new fuel pump. Drove it a week and the same thing happened. Engine just quit while driving , replaced fuel pump and drove it for a week, engine quit again. Towed home pulled pump and only have 6.9 volts with key on. Cranks no start . Pump Hase no sound, no pressure at fuel rail. Pump works when running 12 volts direct

My car has 128000 miles.
My car has an automatic transmission.

Hello. Most fuel pumps require 12 volts to operate, and will not function properly with anything less. This lack of power is likely the reason why there is no fuel pressure and why the vehicle is not starting. The symptoms you describe are commonly caused by an issue with the vehicle’s fuel pump relay or ignition switch. These are the two components that control power to the vehicle’s fuel pump and can cause the pump to not work if they malfunction or fail. I would start by testing the fuel pump relay, which is located in the vehicle’s engine bay fuse panel, and then looking at the switch. If these check out then it may be possible that there is some sort of wiring issue to the pump. As electrical issues can sometimes be difficult to diagnose, I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose what may be causing the issue.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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
  1. Home
  2. Questions
  3. No start, lack of power to fuel pump

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: After fuel pump replacment, car uses more gasoline

There is always a chance of something going wrong with a repair, but let's not start there. There may be a new concern, such as a vacuum leak or a sensor causing false readings. Since there was a recent repair,...

Q: Vehicle not shifting from park.

We need to determine if the shifter is moving and the car is not changing gears or if the shifter is stuck and not moving. Have a technician inspect the parking brake problem. It could be something as simple as...

Q: Was wondering if you knew where the water pump its located on a 9o f250 v10

The water pump on the V10 Ford engine is in the center front of motor above the crankshaft. The pulley for the fan clutch the water pump is behind this pulley. In order to locate a leak you will need...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.