Fuel pressure too high?

[Brucie]

My truck recently started intermittently having a miss. Happens running down the road or just sitting idling. Starts off not too bad but gets worse and finally dies. The only way I can get it to start back up is by draining the fuel filter housing. When I open the drain, there is ALOT of pressure built up. After draining, truck will start back up and run like **** for a few minutes then smooth out and run fine. Fuel pump was sounding kind of bad so I went ahead and replaced it. Thought it was fixed but happened again on way to work tonight. Any ideas on what may be causing this high pressure? By the way, shimmed the FPR about a year ago and got the pressure to about 70 psi and have had no problems since. Any ideas?

 

[BIG JOE]

My truck recently started intermittently having a miss. Happens running down the road or just sitting idling. Starts off not too bad but gets worse and finally dies. The only way I can get it to start back up is by draining the fuel filter housing. When I open the drain, there is ALOT of pressure built up. After draining, truck will start back up and run like **** for a few minutes then smooth out and run fine. Fuel pump was sounding kind of bad so I went ahead and replaced it. Thought it was fixed but happened again on way to work tonight. Any ideas on what may be causing this high pressure? By the way, shimmed the FPR about a year ago and got the pressure to about 70 psi and have had no problems since. Any ideas?

Try taking the shims out ? Maybe the FPR orifice is, or gets plugged by debris (dirt) from inside the filter housing ? What did you use as a shim ?



Joe

 

[early 99 stroker]

just what Joe said..some truck dont like 70 PSI..mine dont..it likes 65 PSI..dyno runs show better HP when set at 65 as well...as long as the pump can hold 65 PSI..

 

[Brucie]

Drove home from work this morning with no problems. Going to take out the shim (SS screw filed down) before driving back to work tonight and see what happens.

 

[Brucie]

Took out the shim before driving to work tonight and truck ran fine. Just seems weird that it would be ok for about a year with the shim and then go bad.

 

[JLDickmon]

return circuit is plugged fulla snot maybe?

what is the actual fuel pressure?

 

[BIG JOE]

return circuit is plugged fulla snot maybe?

what is the actual fuel pressure?

Yep, could be.

You might try blowing some low pressure air thru the return line and cleaning the filter canister out Real good. Sediments/snot could be moving around in there... and it don't take much, to plug the FPR orifice.

You might also have some issues by using a filed off screw for a shim ?? (Binding the spring ?)

 

[Brucie]

Truck messed up again this morning. Got the check engine light so pulled over to gas station. While topping off the tank, ran the DTC codes and had P1280 and P1670. Cleared the codes, left the station, truck running fine but the fuel guage never came up to the full mark. Got the check engine light again and started running bad. At idle it would die but running down the road would be OK. Ran the codes again once home and only had P1280. My book says P1280 is 'ICP circuit out of range low'; code P1670 is 'EF feedback signal not detected'. What do those code mean in English?!?

I will have to put a pressure guage back on to check the fuel pressure, but I dont really think pressure is the problem now.

 

[BIG JOE]

Truck messed up again this morning. Got the check engine light so pulled over to gas station. While topping off the tank, ran the DTC codes and had P1280 and P1670. Cleared the codes, left the station, truck running fine but the fuel guage never came up to the full mark. Got the check engine light again and started running bad. At idle it would die but running down the road would be OK. Ran the codes again once home and only had P1280. My book says P1280 is 'ICP circuit out of range low'; code P1670 is 'EF feedback signal not detected'. What do those code mean in English?!?

I will have to put a pressure guage back on to check the fuel pressure, but I dont really think pressure is the problem now.

Agreed. Sounds like a [Low] fuel pressure issue now. Possibly Air, in the fuel system ?

On edit: You said you change out the Fuel Pump (?), that inlet fitting is Crap to begin with, on the suction end.. you might wana R&R it with fuel hose and 2 band clamps ? Try that maybe ?

 

[Brucie]

Yea, I destroyed the suction line taking it off, so replaced it with clamps and a piece of fuel line.

I've been doing some research on the DTC codes. It looks like may be problems with the ICP or IDM. Is there any way to run some checks on these things before just replacing them, cause that can get expensive quick.