Fuel Pressure. (1 Viewer)

[PanchoLedezma]

Hi Folks, i been workin on a major work on my 80, now i'm in the mode that everything is gonna be take care off on this turn.

Step # 25: I have to test the fuel pressure of the FPR. in some places the test your smoke to see if is compliant, maybe i'll have to install a Regulator valve or something. But first i want to know if is working properly, my question is:

This little bad boy is gonna be put into test, But need to know at what pressure it is supposed to be working when i tested with a pressure gauge.? i'd been hearing 40 psi, other say 52 psi... your knowledge will be appreciated.

Thanks in advanced

Thanks in advanced

 

[gummycarbs]

The FSM says to check fuel pressure at the back of the rail by the EGR valve. I did this. It was a PITA to get to and I chewed up the insulation on the wiring harness (needed to clean and replace it anyway, oh well).

My 94 FSM says pressure at the back of the fuel rail should be 38 - 44 psi with the ignition in the on position and +B jumpered to FP in the diagnostic port. (Though when I did it, I just started the engine...)

 

[inkpot]

Is this on a U S spec OBD II rig? If it is running good why look for problems that you don’t have?

 

[PanchoLedezma]

Is this on a U S spec OBD II rig? If it is running good why look for problems that you don’t have?

I have to keep up with the smog regulations, anything to keep my 80 on the road, and i can trick the test my putting a regulator valve that can reduce de amount of fuel... so i need a thing that i can regulate on the moment... i found a FPR with gauge and adjustable pressure, and i want to put it were the original is... so i need to know what is normal so i can play with the pressure when doing the emissions test

 

[inkpot]

Which stste’s Smog regs? Many states are different. What year is your 80?

 

[bigredmachine]

i would be a little hesitant to mess with the fuel pressure, low pressure can lean out the air fuel mix and cause other issues. I would also be curious how you have to keep up with smog regs as the truck is at least 21 years old, it shouldn't be expected to meet current emission regs, just what the regs were when the truck was manufactured.

 

[scottryana]

That looks like a Lexus valve cover to me, so that means you have a ‘96 or ‘97, if that’s true and it’s an OBDII truck, lowering the fuel rail pressure is not going to net you any better emissions values since the truck is just adjusting fueling based off of the O2 sensor readings.

The minute you dial the pressure down in an attempt to lean it out, the O2 sensor will read lean and just inject more fuel by leaving the injector open longer. What you’re trying to do is hack at best.

 

[baldilocks]

You have emissions testing in Central America??????

 

[PanchoLedezma]

You have emissions testing in Central America??????

Sick! Everybody is under U.N. control, by the " Agenda21 project for a sustainable development " Big Cities have to comply.

Agenda 21 in 10min
Agenda 21 in 5 minutes

 

[gummycarbs]

I think those videos just made me dumber. I better go drink a Brawndo.

 

[Tools R Us]

That looks like a Lexus valve cover to me, so that means you have a ‘96 or ‘97, if that’s true and it’s an OBDII truck, lowering the fuel rail pressure is not going to net you any better emissions values since the truck is just adjusting fueling based off of the O2 sensor readings.

The minute you dial the pressure down in an attempt to lean it out, the O2 sensor will read lean and just inject more fuel by leaving the injector open longer. What you’re trying to do is hack at best.

Agree, also reducing rail pressure is likely to reduce fuel atomization. Bigger droplet size is likely to reduce power and increase emissions. The factory FPR is vented to the manifold, so compensates for change in pressure, don't see changing to a fixed regulator improving emissions?

 

[baldilocks]

Sick! Everybody is under U.N. control, by the " Agenda21 project for a sustainable development " Big Cities have to comply.

Agenda 21 in 10min
Agenda 21 in 5 minutes

I’m sorry to learn about your nightmare.

 

[avdeveloper]

Sick! Everybody is under U.N. control, by the " Agenda21 project for a sustainable development " Big Cities have to comply.

Agenda 21 in 10min
Agenda 21 in 5 minutes

bro, its agenda 2030 now.