I recently replaced the #6 injector. Once replaced I realized that the fuel transfer pump was out. replaced that, and the truck would run for about 5 minutes and die. I was told it was the cp3 pump getting hot. so, i replaced the cp3 pump. still does the same thing. it runs, then it bogs down and dies. im clueless here and tired of mechanics making stuff up thats costing me money and not fixing the problem.

 

I suspect you have another injector issue, especially if it runs for a bit and then dies. Another thing I would do is: as soon as it bogs, shut it down and pull the fuel filter lid. If it's not full, you need to look at delivery. If it's still full, you need to get it hot and check fuel return flow.

 

What if any fault codes are you getting? thats where you should start. You meay need to replace the Camshaft Position Sensor (CKP)

 

well i just got the cp3 on friday. the check eng light was on and then went off. didnt have enough time to check what code it was.

sorry i tried changing my info and cant figure it out. this is a 04.5 cummins no mods.

 

A run of the mill OBD II code reader will display why the CEL (MIL) went on and codes, etc. If you have a Pep Boys, Advance Auto, etc. they will usually let you borrow the reader if you leave your driver's license. Even if the MIL goes out, there will be a stored code. Some will even show pending codes and real time data.

 

Turn you key on, off, on, off, then back to on. The codes will come up where your mileage is displayed. Have a pen and paper ready and post back with your results........ Might be on, off, on, off, on, off, on! Can't remember! But do not start the truck when you are doing this.

 

Ok, i got codes. P0148 (fuel pressure relief valve) and p2123 and p2121, good lord, im looking at what this consist of and all i see are $$$$$$$$$$$. Im all about doing the work myself but am having trouble finding instructions.. any help?

actually work looks easy.. looks like the valve is 233.00 if yall know where i can get it cheaper please let me know.

 

The fuel pressure relief valve would cause this issue. Here are what your codes mean.

P0148 High Pressure Common Rail (HPCR) Fueling Error Checksum

P2121 APPS Conformance Error
P2123 Throttle/Pedal Position Sensor/Switch D Circuit High Input


You need to inspect your rail pressure relief valve. Don't remember the specifics of how to test it. From the codes, it looks like your APPS is going out and causing all of your issues but most of the time you will get a dead pedal when it is having issues.

 

just so you know its almost cheaper to buy a new rail assembly with the valve than just the valve. you can buy a solid bolt to put in the banjo ontop of the relief valve and see if starts/runs to determine if that is the problem. don't leave it in there though you need the valve to bleed off pressure spikes in the rail. and you can't just look to see it there is fuel ontop of the relief valve because it comes from the return line off the back of the cp3.

 

Thanks for the info guys.. I tested the relief valve and its good.. Not real sure whats going on.. just going to take it in and have them run full diagnostic on it..

 

It's the Apps. Try a reset and see if it corrects it. Disconnect both batteries for 30 min., turn key on then off. Hook batteries back up turn key on. Depress the go pedal real smooth and slow all the way to the floor. Turn key off. Restart truck and see if it helped. If not, it needs to be replaced.

 

Its in the shop right now.. Im sure he will try and reset it.. if its bad, where can i find one.. only finding them for the 02-04.

 

Anyone know where to get an apps? mine is no good.. need to find one for less than 500.. may not be possible but worth a shot.. where in the hell can you get one anyways? Im not seeing them anywhere on the internet.

 

Moparparts.com I think that is what the website is called.