Has anyone seen this problem? It is a 2002 and four injectors were tested and found to be bad. We installed the four new ones all on the same side for future diagnostics. Now we have 15K rail pressure at idle. :banghead:

Has anyone seen this problem? It is a 2002 and four injectors were tested and found to be bad. We installed the four new ones all on the same side for future diagnostics. Now we have 15K rail pressure at idle. :banghead:


I would bet your Fuel rail pressure regulator on the CP3 is junk also. I had the 15K at idle problem not to long ago. Idle was noisie and would sometimes lope. Also truck would surge around 2000rpm no matter the program.

We are changing that out now. Volker happened to stop in and he agreed that it could be the problem and the one we took out measured a slightly different dimenson of the plunger depth than the spare one we had. We don't know if the spare is good though.

What was the reason for injector change?
If rail psi was ok at idle before now higher after I would look at the Rail sensor % value. And graph the regulator. Does the actual and desired psi compair and equal or all over the place....Mark feel free to call if needed...
503-369-7595.
Patrick

Bill can call to if needed....

Here is the update. We tried a used fuel pressure regulator and had about the same result. Then we installed a new one and it works the same way. Now what? The truck came in with typical injector problems. We sent the injectors to be tested and four failed. Four new injectors were installed and then this new problem shows up. The problem was not there before the injectors were changes. Any suggestions?

why injector change? High balance rates? smoke? Ok now with truck running
what is rail psi? can you ramp up the psi? Did you send out all 8 injectors?
Try making fuel psi to max can the pump put out full psi. Does the truck have any power adders on. if so go back to stock. is the only issue high rai psi.
remember also to look at the regulator %. check the rail pis sensor as well. remember the regulator only controls the psi. the reading comes from the rail sensor on the function block. the block is on the driver side below the intake tube to the turbo. If all that was done was injectors, recheck all wiring conections. the rail sensor and engine harness. Did Bill do the work?
looks like a mess I am sorry. Call in needed.....Good luck
Patrick

Does this truck have a lift pump on it? If it does what is the pressure at the OEM filter head. If it is over 12psi that can anger the FICM and cause high rail pressure at idle. If it doesnt have a lift pump I not sure what to say.

WAG

What would happen if the return from the low side of the CP3 is plugged and hosing things up?

Hope that helps

Let me know

Does this truck have a lift pump on it? If it does what is the pressure at the OEM filter head. If it is over 12psi that can anger the FICM and cause high rail pressure at idle.


Ding, ding, ding! :D That is exactly what the problem was. This truck has a pump that uses a return line back to the fill neck. The feed pump return line got kinked and caused the pressure to be too high, in turn causing the high rail PSI at idle. I disconnected the pump and hooked up a hose to the hard line after the feed pump and put it in a fuel can. Problem gone. Funny how these things show up after something else that is non-related and kicks your but.:rolleyes: Thanks for everyones help!

Mark

Wahoo!:D

Glad to here it is running right again.

Nice to see you got it fixed.. now go blow smoke... :D

-Colin

to many dam lines and hoses and harness in these new trucks.