Sputter

[1987rangerxlt]

The truck sputters on acceleration. It runs fine when not accelerating though. I just smogged it and it passed, with new spark plugs, wires, air filter, oil change, and fuel pressure regulator.

Any ideas? Maybe the o-ring on the fuel pressure regulator is bad again. I replaced the whole thing last time because it was old even though it could have just been the o-ring.

 

[RustedRanger]

If the O-ring was bad it would be leaking fuel. I don't see a fuel filter on the list of things your changed....did you change it?

 

[jhammel85]

Did you do the cap and rotor? I think it sounds like it could be a spark issue. Maybe even a weak, dying tfi module.

 

[Ken the BEAST]

My truck is having pretty much the same problem. I know you have prob already done it but double check your timing and firing order. If you can pull up some codes using a multimeter or a code reader. Do a fuel pressure test at idle and check as you rev through the rpm range, should be about 40 or so. If it is good at idle and lowers at high rpm it is prob your fuel filter. In my case im pretty sure its my injectors, but your case might be different.

 

[RyanL]

My truck is having pretty much the same problem. I know you have prob already done it but double check your timing and firing order. If you can pull up some codes using a multimeter or a code reader. Do a fuel pressure test at idle and check as you rev through the rpm range, should be about 40 or so. If it is good at idle and lowers at high rpm it is prob your fuel filter. In my case im pretty sure its my injectors, but your case might be different.

How exactly do you check the fuel pressure though? I went to autozone and rented one of their kits, but it was useless because none of the fittings match up to the tiny little tire valve stem looking one on the fuel rail. Same with the pressure tester which they sell. I guess you could cut some fuel lines somewhere and test that way, but I didn't want to do that and besides, testing it at the fuel rail will let you know if the fuel pressure regulator is working right.