Well, looks like I am buying the 03 QC DRW I looked at today, close the deal on Tuesday. Can anyone point me in the right direction (thread) so I can read up on this pump and CP3, so I can be prepared for it. Cost? Ease of replacement? On my Ford PSD, I (along with everyone else) would carry a spare CPS in the glovebox with a 10MM wrench. Thanks!

 

https://www.dieseltruckresource.com/...ad.php?t=78702

 

After replacing CP-3 truck still wouldn't start. Found the "By Pass" valve was stuck open and would not allow rail to get up to running pressure. This was per Tech. He left the new CP-3 on and which quieted down the truck very much.

At least it's back on the road again.

 

I think the tech meant the rail over pressure relief valve, not the bypass valve.

Funny they can't get the terminology right on this stuff.

 

they also refer to it as a "Fuel Rail Pressure Regulator". I also have another book that calls it a "Pressure limiting valve". The psi limiting valve would be a more accurate description I think. Funny thing too is that the only ones I've had to replace were trucks with performance enhancing devices installed on them. I think these boxes are increasing the rail psi, which pushes the psi closer to the threshold of what the limiting valve can hold. You can only hit that valve so many times before it fails. At that pressure when it unseats it will cut the sealing surface inside the valve and then cause it to leak which in turns causes the rail pressure to lower.

 

I think the fuel rail pressure regulator is on the CP3 (the only electrical connection on the cp3 pump).

The regulator on the cp3 controls the rail pressure. The bypass valve (or pop off valve) just bleeds off rail pressure if you spike it too high (QUAD Race Box?????).

Incidentally, the valve is designed to still allow 70MPa of pressure in the rail at full bypass flow. You only need 40MPa to start the truck. I dont' think you are getting the whole story from your dealer as SuperDuty pointed out earlier.

I disagree with lift pumps failing cp3's. I agree that bad lift pumps failed many a VP44 on the 2nd gens, but I think the CP3 is getting a bad rep. unfairly due to the second gen problems.

Just like in this case, "The lift pump failed, my truck died, so it must be the main pump". It's usually not the CP3 (as someone stated earlier, they might leak, but very few failures that leave you stranded especially when compared to the number of "stranded" failures on the VP44).

Now there is just one more CP3 on the warranty books that wasn't actually broken, making the reputation even worse.

 

....that would be the "Electronic Fuel Control Actuator"....and it avail separately now finally.

 

That should help the Cp3 warranty.

Some say toemaytoe, some say toemahtoe.

 

Just to update you guys (not that you care ), but these CP3s must be hot properties. STAR authorized my dealer to order one last Friday (12/23), and it STILL ain't in.

 

mine was ordered along with an in-tank liftpump Monday morning. They said Thursday or Friday...we'll see I guess..LCH

 

Mine was ordered Wednesday before Christmas weekend and arrrived Monday am and got truck back Monday afternoon. Engine is much quieter again and seems to run jsut as good as it did before failure so hopefully all is well. Have been driving for last 2 days as we are leaving on "vacation" tomorrow am. Will check in for the next 2 months as I can from the laptop. As far as the terminology I mispoke , the tech was correct. Just a senior moment which lately have been more frequent.

Thanks for the replies.

Don

 

We have two on the shelf + 8 lift pump conversion packages!

 

It's not like I'm in the boonies, either. This is suburban Philadelphia. Tomorrow morning (Friday) will be one week. I'm going to have to call them tomorrow.

 

Talked to my dealer today, cp3 is coming out of saint louis and was shipped yesterday. Lift pump coming from somewhere else and was shipped today. She first told me the lift pump was on backorder but checked for me and found that it was released & shipped. I heard her say backorder and I thought here we go . I'll still be lucky to get my truck fixed by Tuesday..it's running fine but I don't trust it knowing whats wrong with it...LCH

 

I just spoke to my service manager. He said the pump is in, but "two other pieces" that are needed are not in yet. Maybe next week.

Sure glad this is not an item that caused my truck to be down.

Anyone have any idea what the "two other pieces" might be, because he didn't know.