HELP, loosing rail pressure after 1/2mile
 

Alright, I am about to lose my mind fooling with this truck. My injectors went bad a couple months ago @ about 150k miles. I put a new set of Bosch injectors, truck ran great and quiet. Not long after that the lift pump went bad so I put a AirDog 2 in. After putting the AirDog 2 in thats when things started. The truck started right up and rail pressure at idel is 7k and smooth as silk. I take the truck down the road for a shakedown run and it did great. Then about a half mile down the road rail pressure drops to 3k no acceleration and temp gauge sky rockets. I bring it home, and order a new High pressure fitting, gear pump, FCA, and Cascade valve for the CP3 injection pump. I install everything and once again the truck starts right up sounds great half mile in same issue. The only thing I can think of that I havent changed is the Rail Pressure Sensor. My OBD-II keeps throwing a code P0148 Fuel Delivery Malfunction. Does anyone have any idea what I can do to figure this out. Any help would be greatly appreciated.:argh::argh:

You put a new CP3 in? Call Todd at T&C Diesel!

could be the pop off valve on the rail

Cummin_un_glued, yeah I just checked it and it is not leaking. that leaves me with one last part before replacing the entire pump and that is the rail pressure sensor.

This injection pump business is shady for sure. Between not being able to get ahold of some and the others telling you just enough to not give up the ghost it is ridiculous. Seems to me like everyone would rather sell you a pump rather than help you trouble shoot. Makes me wonder how many people out there have been sold a new IP that didnt need it and then turned around and had to buy something else to fix the problem.

Finally I talked to Oregon Fuel Injection and they had no problem in taking the time to walk me through the trouble shooting steps and answered the phone every time I called.
Talk about a frustrating ordeal, I don't have a problem buying a new pump if I have too but it is nice to have someone walk you through it just in case you don't need it.

Even tho its not leaking i would swap it with another trucks just to see

Sent with a Droid RAZR in one hand and 14,000 volts in the other.

I wish I had someone that I could do that with but unfortunately I don't. I did check my voltage from my ECM to the FCA and it was a little over 6v so it should be good from a wiring standpoint. I am about to pull the RPS and check it for any signs of failure like cracking and may try to test it with a meter. If it is still having a problem with fueling then I will get a new stock Bosch CP3 and put my modded gear pump, high pressure fitting, FCA and Cascade valve and that should make it more efficient than the OEM unit.

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My understanding is that the CP3 is pretty much bullet proff as long as it is kept clean as in fuel and no water. This is the first problem I have had with my fuel system and the truck has 161K on it. I have never had water in fuel and I kept my fuel filters changed regularly and I ran diesel conditioner in it pretty often. The pump itself has no leaks whatsoever so I am hoping that it is just the RPS not reading correctly. I know if the RPS does not read correctly it cause the FCA to act accordingly.

Have you checked your tubes?

Sent with a Droid RAZR in one hand and 14,000 volts in the other.

Yeah, here in a little bit when it cools down I am going to torque check them again just to see again.

I would probably pull the tubes all the way out and pop the injectors loose and go thru the torque spec again. Takes a little time but your probably going to loosen them some trying to loosen the lines.

Sent with a Droid RAZR in one hand and 14,000 volts in the other.

Well everything is torqued and correct, I guess I will put the new RPS on in the morning and see what happens. If I do end up having to get a new pump after tomorrow before i send it off I will remove all the plunger plugs and inspect and take pictures. That way I see for myself what is going on and have an ace in the hole in case someone try to bump me on the core charge. I will post up tomorrow and let you know what happens.

By the way thanks for the trouble shooting help.