Signs of a bad or going bad fuel sending unit or pump

[Koast]

First of all let me say I understand this job is not fun but that's okay it's not my only vehicle. I have a 98 suburban 2500 and what are the signs that the fuel pump is going bad? At this time the issues that have me concerned is a very twitchy fuel gauge. Another sign is that I will drive it to work and after it sat in the sun for a little while and I go to start it again I turn the key and it hesitates to start. And what I mean by hesitate it's like when you go to start a vehicle and you haven't turned the key long enough in the engine just barely catches fire and then starts up if that makes any sense. Truck has 217,000 miles on it. Filter has been changed.

 

[PlayingWithTBI]

Get a pressure gauge - s/b 60PSI min.

 

[XJPhoenix]

When you say, 'hesitates to start', do you mean the engine turns over slowly, as if it didn't have enough power in the battery to turn the starter fast?

 

[tinfoil_hat]

Glad you posted this. I am having the same issue.

 

[likestrucks]

Subd, mine does the same thing.

 

[Ledzep]

Some signs are intermittent crank no start, very loud whiney fuel pump. If it is a no start kick or mild hammer to the middle of the tank while cranking if possible, if starts needs pump assembly

 

[jaywestfall]

My experiences with fuel pump failure are no warning. They just shut off. I have replaced two so far.

 

[SHRT 1]

Put the pressure gauge on - should pop up to about 60psi with key on, engine off. Watch it and see if it bleeds down. Some is OK but below 45psi/50psi and you may have a leaking pressure regualator inside the intake. Note- I replaced my MPFI with the SFI set up from GM - after a couple of weeks started to have this issue - by removing the throttle body and using a remote camera I found one of the injector lines (heat sealed) at the injector leaking. Lucky that he dealer warrentied it.

 

[stutaeng]

My buddy has a '01 Silverado with the 4.3. He recently replaced fuel pump for the 4th time at around 365k miles. He said it started, sputtered and died.


I was also under the impression that they either work or they die...

 

[PlayingWithTBI]

I was also under the impression that they either work or they die...

The impeller (especially cheap plastic ones) in the pump will wear over time and produce less flow and/or pressure.