should i change out fuel pump?

[tpricez71]

Hey guys, i could use some advice. My 96 tahoe has developed a miss/rough idle recently. In an effort to repair i did a tune up of sorts. I replaced distributor,rotor, wires, and plugs. no luck. I had the fuel pressure checked and it was 55 lbs when engine was running. when turned off pressure went to 0 almost imediately. the mechanic who checked it for me said it was fine, but my hayes manual says 60 to 66. Is my fuel pump defective?
I would appreciate help from anyone who knows. thanks

 

[95TwinTT]

The fuel pressure should be slightly lower while at idle or cruising. Fuel pressure regulator on the end of the fuel rail, lets more fuel return to the tank controlled by vacuum from the intake manifold.

Try checking the fuel pressure without starting the engine.

It does not sound like your fuel pump is a problem yet. I would worry about it if it can’t keep up when at wide open throttle………

 

[96ProCompTahoe]

might try changing the fuel filter if it hasn't been done in a while.

 

[steamroller]

I had the fuel pressure checked and it was 55 lbs when engine was running. when turned off pressure went to 0 almost imediately.

Leaking fuel pressure regulator, it should hold pressure even after you shut it off not drop immediately, probably leaking raw fuel into the intake causing your missfire/rough idle issue

It will be apparent if this is your problem if you pull off the upper plenum and the intake is spotless around the regulator and the rest will be covered with carbon due to the EGR

 

[Dlong30]

Leaking fuel pressure regulator, it should hold pressure even after you shut it off not drop immediately, probably leaking raw fuel into the intake causing your missfire/rough idle issue

It will be apparent if this is your problem if you pull off the upper plenum and the intake is spotless around the regulator and the rest will be covered with carbon due to the EGR

+1

 

[99 2dr]

I just went through that problem my self, the pickup tube on the pump had a small pinhole rubbed in it. Does the truck sometimes take a while to start?

 

[96_2DRSPORT]

I just went through that problem my self, the pickup tube on the pump had a small pinhole rubbed in it. Does the truck sometimes take a while to start?

mine is! im gonna closely watch this thread

 

[tpricez71]

thanks to all who responded. i took the hoe in for a diagnostic today and was told my ck engine light doesnt work, hense no codes. the problem im told is the fuel pressure regulator, so give a cigar to my fellow hoe owner who said it was such. they want 450.00 to install a 65.00 part, uh no! so guys how big a PIA is changing the regulator? do yall have any tips to make it go smooth as possible? i eagarly await your responces.
tony

 

[Broken Truck]

IIRF it is under the manifold so not easy to get to...

but, hey...it's all just nuts and bolts and gaskets....

 

[mikeyboy]

does the truck come up with any codes