oh that sucks. So fuel pump, or could the filter cause a pressure drop like that? I changed the gas tank awile back, that was a job. But I reused the pump assembly cause it was OK and cost way to much to replace. The fuel filter I'd say has over 50K on it - lines are rusted good, never wanted to mess with it.

 

Yes, the fuel filter could be so clogged it's not allowing enough fuel through it.

Spray the heck out of the fittings with PB Blaster and get the correct size flare nut wrenches. Regular wrenches or an adjustable will simply round the heck out of the nuts and ruin them.

 

The purpose of testing at the fuel filter is to see if the problem is still there after disconnecting the rest of the system (the spider & fpr). If the problem is still there, then the pump is at fault. If it isn't, then the FPR or spider is the next likely source of a leak.

The fuel filter could cause a low pressure condition while running while there is demand for fuel, but it would have to be severely clogged to cause a lack of fuel pressure at start up; so much so that it would have some pretty significant issues while running. And a fuel filter will not cause the pressure to bleed down after the pump shuts off.

 

finally fixed the problem. wound up changing the coil, and now the truck runs like a champ. thanks for the help everyone.

 

Could have been an inaccurate gauge showing a low reading. Glad you got it fixed!

 

I tried the starting fluid, nothing happened. The I checked the fuel pressure again, this time it spiked up to 60+ psi for about 3s, then dropped down to 52psi. Maby I had the gage on wrong before? so I started looking for spark again, took the coil out to check the primary & secondary and notice the sides were burnt up - so another $40, and it runs! any reason GM paints the coil mounting brackets? I always thought the coil bracket needed to be grounded. I removed the paint in some spots to make a good ground this time.