What is the best way to check a cp3?

02psd7.3

02psd7.3

New member
My lift pump went out on me last sat. I drove the truck about 5 hrs with low psi. I had like 11k on the flat and would drop down to like 3k on big hills. I did my best to keep the psi up I slowed to like 30 mph to keep psi up.
My question is what do I do to check the cp3 to see if its bad? Do I just put the air dog on and check my rp?

Thanks
 
cp3's aren't really like the old VP 44 pumps that would die without pressure.

put a new lift pump back in and go drive it.
 
if your lift pump went dead then you prolly starved the cp3 which may have damaged it therfore if your cp3 is not fueling enough then you will damage ur injectors...i have a saved paged on my computer that shows you how to check ur cp3
 
I doubt you did any damage to your cp3, the factory lift pumps are pull through types, and your cp3 can draw on its own, not like it was dead headed.

Change up the lift pump and should be good to go.
 
Isn't this the same CP3 that the duramax uses? They don't use a lift pump at all.
 
the diesel liberties use the same cp3 as the dodges and they work of the vacuum the cp3 has, no use of a lift pump. straight draw from the tank..
 
dodge cp3 need a lift pump to work properly...duramax pumps dont really need the use of a lift pump because they have a suction dodge doesnt.
 
the fca on the d max is different i can tell you that if you put a dmax fca on a cummins pump it does some crazy sh*t
 
what are way to tell if my stock lift pump is going bad? Mine chatters, or something back in that region chatters, every once in a while at idle, if i give it a little throttle is goes away.
 
BFD99 said:
what are way to tell if my stock lift pump is going bad? Mine chatters, or something back in that region chatters, every once in a while at idle, if i give it a little throttle is goes away.
Click to expand...

flow test it....minimum of 450ml in 10 seonds....take the tube that goes between the cp3 and the fuel canister and put a longer tube on the fuel canister side and put the other end in a graduated cylinder and turn key on to bring fuel up to end of hose and put your finger on it and then have someone bump the key and allow the fuel to go into the graduated cylinder and count 10 seconds (do it about 3 times to get an average) if its less than 450ml time for a new one. Hope this helps
 
will dodge warranty the lift pump for the 100k mile warranty? I'm at 82k and was just wondering. I know i need to go with an airdog but i'm afraid my stocker is going out. Thought i might get them to buy me a new stocker to get me by for awhile if its under warranty.
 
CumminsDriver said:
is the cp3 on your truck stock or a duramax pump?
Click to expand...

the pump on my truck is a dodge pump

but we tried a d max pump fca on my buddys 06cummins to see what it did and it loped and had 25k psi at idle

o also i have the DIY stage 2 pump mod done also
 
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i had a new jd sprayer givin rail problems and it would not fall on its face till -8psi and its suppose to min of 5psi so i would say u would have any damage
 
ok sothere is no way to test a cp3?

my air dog should be here any day now so i will put it in and see what my rp is
 
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