Fuel pressure regulator
- Thread starter dproffitt
- Start date
Well tested from pin to fpr and everything tests good. Still no voltage to the fpr with key on and truck throws code p0090. Truck cranks but won't start. I'm considering ecm is bad but am.looking for any ideas or second opinion beofr I spend that kind of money
Nothing to the fpr is why I'm wondering if the ecm may have some bad spots. I figured there is more wrong. Just figure it all in the ecm. Truck fires on ether by the way.
Do you have a way of comparing desired vs actual fuel rail pressure while you are cranking? And if you start the truck, is the fuel pressure normal for the conditions in which the truck operates?
The fuel pump runs at full pressure all the time. The FPR is a solenoid that limits the pressure created by the fuel pump in the fuel rail. The Fuel Rail Pressure Sensor sends rail pressure info to the ECM so that the ECM can make the correct decision on how much to limit the pressure.
The fuel pump runs at full pressure all the time. The FPR is a solenoid that limits the pressure created by the fuel pump in the fuel rail. The Fuel Rail Pressure Sensor sends rail pressure info to the ECM so that the ECM can make the correct decision on how much to limit the pressure.
The truck will not start unless you give it some ether and will shut off as soon as you stop spraying ether. If there is a issue with the fuel rail pressure sensor will that make the ecm not send any voltage at all to the fpr
I understand that it will not cause a no start. My question is is there anything that would prevent the fpr from getting any voltage like another sensor or a faulty ecm
I used a common ground (negative on battery) no voltage and checked ground wire and it was making good continuity. Checked continuity on both wires to correct pinout on the c1 connector and showed good continuity. Didnt check resistance. What would be a good number for that.
Yes I've tested with the key on. And no question is a stupid question lol. Haven't checked fuel pressure. Figured if I find out what the fpr problem is that may solve the start issue cause the code never came up till the truck refused to start. Figured the 2 were related. Especially since there is no voltage coming from the ecm. Would a problem with the fuel pressure sensor cause no voltage to the fpr from the ecm
I dont think the engine needs the fpr to run, it'll make max rail without it is what 2004LB7 is saying. Hook efi up and log FRP and DFRP see what it says while cranking.
I understand all that. I'm just trying to fix one problem at a time. And right now code p0090 is the only code up. My plan was to figure it all out and hopefully whatever is keeping the ecm from getting voltage sent to the fpr will be my issue. Even if it's the ecm it's self. I don't have a computer to hook up to it. All I have is a small code scanner. I'm working on getting someone out to hook a computer up to it hopefully soon. When the truck decide to not start on me this code came up at the same time.
no start conditions rarely are accompanied with a code that is directly related to why it won't start. more common to have the no start creating other codes that go away once the engine is running. some like crank and cam sensors can be helpful but fuel pressure ones usually are not.
crack open one of the high pressure lines and see if you get fuel when cranking. if so then unplug the pressure sensor and see if it fires
crack open one of the high pressure lines and see if you get fuel when cranking. if so then unplug the pressure sensor and see if it fires