Q: Low fuel pressure at the fuel rail (30psi) then drops to 10psi occasionally while idling. The fuel sending unit was just replaced. 2004 Dodge Dakota

asked by on January 31, 2017

Just replaced the fuel sending unit, but still have low fuel pressure (30psi) and flictuations (down to 10psi). The truck runs decently, but has low power and bad mpg. It also has trouble starting when trying 15min to 2hrs after turning it off. I've already replaced 02 sensors, cam pos sensor, crank pos sensor, throttle pos sensor and map sensor. Any ideas? I'm out of guesses. Thank you Dennis

My car has 160000 miles.
My car has an automatic transmission.

Loss of power Inspection $94.99 - $114.99 Get a Quote

Hi there - yes, you clearly have a fuel supply issue, mainly focused on getting enough pressure in the fuel rail to the injectors. Check problem codes first, even if the Check Engine light is not illuminated. I suspect your problem is related to either the fuel pressure regulator, or the fuel pump check valve. either of these could cause low fuel pressure. A clogged fuel filter or weak fuel pump could also be the source here. I recommend a loss of power inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What does the emergency trunk release lever do?
The Honda Accord features an emergency trunk release lever in case someone becomes trapped in the trunk. To use the lever, simply push it in the direction indicated by the arrows. The trunk lid will open and can be pushed...
Car starts, but won't go forward
The fluid would not be an issue unless the fluid has leaked out. The transmission fluid shouldn't need to be changed or flushed out in this case. The transmission front pump may have failed due to leaking internal seals. The...
Fuse A/C power windows
Hello, thanks for writing in about your 2005 Kia Spectra5. It sounds like those systems may all share that same fuse and one of them is drawing too many amps, or there is a short in the circuit. I wonder...
Transmission stuck in park
In order to shift out of park, the transmission module needs to see the engine idling and the brake pedal depressed. If one of these criteria is not met, then it will not let you shift out of park. There...
Battery dead after car sat for one month
Hi there. It sounds like the battery has an internal short. I would replace the battery (https://www.yourmechanic.com/services/battery-replacement). I would also make sure that the connections at the battery cables are clean and tight (https://www.yourmechanic.com/article/how-to-clean-battery-terminal-connections-on-a-car). If they are loose at all,...
My car won't start - 2007 Nissan Xterra
Hello. If the vehicle will not do anything at all, then I usually start by having the battery load-tested (https://www.yourmechanic.com/article/how-to-check-a-car-battery). If the battery has failed (https://www.yourmechanic.com/services/battery-replacement) or shorted internally, then it will not even accept a jump start. This needs...
I have a 2014 Chevrolet impala my gas cap has a yellow gas cap and says E85... Will it be ok to put that in my gas tank with unlea
Hello, yes, it is ok to put unleaded gas as well as E-85 fuel in your vehicle. The vehicle has the ability by way of the computer to calculate the type of fuel and control fuel ratio to get the...
Makes a scraping noise when pulling a hill in overdrive
Hi there. The transmission is slipping in the overdrive gear. If the noise goes away when the rpm's increase dropping the transmission out of overdrive, then the overdrive gear clutch pack is slipping. I recommend seeking out a professional, such...
Why does my 2005 Ford Mustang make a rattling and knocking noise
Hello. Most of the time this is caused by an issue with the timing chain or chain tensioners. The front of the engine would need to be disassembled in order to locate where the noise is coming from. Most of...

Related articles

What Causes Fuel Injectors to Get Clogged or Dirty?
Fuel injectors deliver fuel into the cylinder for combustion. Clogged fuel injectors can be caused by debris or impurities in the fuel.
A Buyer’s Guide to the 2012 Dodge Avenger
The The newly redesigned 2012 Dodge Avenger is a really impressive addition to the mid-size sedan market. This model is Dodge’s answer to the likes of the Honda Accord and the Toyota Camry, and while it may not have quite...
How to Replace a Fuel Pump Relay
The fuel pump has a relay that fails when there is no audible humming sound as the ignition is turned and when the car cranks after longer than usual.