Fuel pump failing likely cause of power loss
Pressure specs should be tested
DEAR CAR TALK: I own a 2002 Chevy Suburban with 178,000 miles. I bought it from my brother-in-law for $3,000 for my son to drive while in college. It has died several times on the highway, causing him to pull over quickly to get out of the way of traffic. Before it dies, he feels a jerkiness or a rumbling. The car then loses acceleration, and pushing on the gas pedal gets no response. He can then coast to a stop or push the brake pedal to stop on the shoulder. It usually will restart in a minute or two, and runs normally thereafter. Occasionally, it has died several times within an hour while driving on the highway. Recently, the Suburban died on the highway on our way to visit family for a holiday. After restarting, it ran for over an hour, getting us to our destination without an issue. The dealership can’t seem to find anything wrong with it. However, they say the fuel pump is on the low end, but they tell me it appears to be within the range required for the vehicle. What should I have the dealership replace or check? —Mike
You have the classic symptoms of a failing fuel pump. It usually dies intermittently, usually on the highway on long trips, after it’s been working hard at high pressure and heating up.
It’ll fail just as you described, by slowing down the flow of fuel, which makes the engine lose power, or chug or stutter, and finally conk out completely. After a short period of time, it’ll cool off enough to allow you to restart the car and drive away. Until it fails again. Which is going to happen more and more often.
If you have a helpful mechanic, he might be willing to put a fuelpressure gauge on the truck and drive the car home himself overnight. If he can get it to fail, he’ll actually see the fuel pressure drop as the vehicle falters.
I suppose it could be a bad crank angle sensor instead, which could create the same symptoms. But the fact that your mechanic found the fuel pressure to be low (even if it was technically within specs at the time of testing) makes me think that the fuel pump is more likely at fault.