Is my fuel pump on the way out?

[DYZ]

Hello all,

This happened a few times in the past several month. Basically, it feels like the car cuts off the fuel for a split second, but after that the car drives fine like nothing had happened. Yesterday the car did the same thing, but not too long after that, the engine shut itself down. I had no problem to restart the car immediately and it again drives like nothing had happened. There is no check engine light and I found no generic code stored in ECU. Is this a typical signal of bad fuel pump? Thanks!

DYZ

[Astro14]

More likely a MAF on the way out than a fuel pump...any noise from the pump? They usually get noisy before failing.

You might try cleaning the MAF and see if that helps. On my XC, I finally just replaced the MAF at 165.000 miles...cleaning wasn't helping any more...and it ran like new after.

[IVIUSTANG]

My fuel pump actually had similar issues to that before it died. Under heavy load it would sometimes cut out for a second, in hot weather it would stall; but would restart and run ok for another short while. My pump made no abnormal noises. It's possible, but try the MAF first.

Jesse

[Vicious Meistersinger]

Throttle body could be getting gunked up. Is it a slight hesitation as you give it gas?

[DYZ]

Thanks, guys!

Both MAF and TB were thoroughly cleaned when I took the engine head off for valve repair a few thousand miles ago. I thought dirty MAF would cause rough idle, but the car runs/idles fine beyond those moments when this happened. Would a bad fuel pump eventually throw a code? Maybe I'll have to live with this until it gets worse or throws a code.

DYZ

[IVIUSTANG]

Mine threw fuel pressure regulator performance codes on its way out.

Jesse

[DYZ]

I did a fuel pressure test today using the kit borrowed from AutoZone. I'm not sure if it shows anything wrong. Here is the observation: at idle it reads 42 psi; while reviving the engine it also reads around 42, but when coming back to idle, it would shot up to 70 psi then gradually comes down to 42 psi. Is this normal?

DYZ