Fuel delivery issues

[Arthur Jensen]

Hey all,

I've got an 88 XLT, 2.9l rwd with a stock fuel system.

She splutters and starves for fuel when
1) at operating temps
2)when letting off the accelerator

I've replaced both the in-tank fuel pump, the inline pump, the filter and that weird little canister between the tank and high pressure pump. I really don't know what else to look at and could really use some advice.

 

[RonD]

Why do you think its a fuel issue?

And a little confused about "2) letting off accelerator"

There is a fuel pressure test port on the engine, you can rent a pressure gauge but they are not expensive, same as a tire pressure gauge but it needs to screw onto the test valve
Running pressure should be 30-35psi

There is also a FPR(fuel pressure regulator) on the engine, it has the RETURN fuel line attached and a vacuum line
If FPR fails then pressure drops to almost 0psi
OR tops out at 80psi
Either would be bad
But this would be a running issue ALL THE TIME, no difference warm or cold

Running issues after warm up can be a TFI module(spark) issue, very very common issue for these to become temp sensitive
Or computer, needs 2 or 3 capacitors replaced, cheap

 

[Busypees]

Hey all,

I've got an 88 XLT, 2.9l rwd with a stock fuel system.

She splutters and starves for fuel when
1) at operating temps
2)when letting off the accelerator

I've replaced both the in-tank fuel pump, the inline pump, the filter and that weird little canister between the tank and high pressure pump. I really don't know what else to look at and could really use some advice.

It might be a good idea to check your fuel pressure. If fuel pressure is good then the only other issue I can think of fuel related is maybe bad fuel?

Also if check your fuel pressure during idle and load it will let you know if you bought a faulty pump or possibly if theres a small block in the fuel line.

 

[Arthur Jensen]

Aight, so in my ignorance, I didn't think and do my homework. It was the TFI module that had gone tits up. The truck runs like top and I'm kicking myself for everything that I replaced prior.

Your help is much appreciated guys.