j

since my airdog 150 took a dump, and it will be a few days til the new one comes, is it safe to drive with just the cp3 pulling fuel? as long as i drive slower and dont get in the skinny pedal ? when the ad150 went out, it still ran all the way home and had plenty of power still..

John Faughn

I would say that's asking for trouble , it would kill the the VP in the older truck , but is still just taking life out of your CP3 .

jiggerman78

just go get a holley or blue or red since it will just be a quick replacement and than return it when the AD comes in.

rip 112

The CP3 is capable of drawing fuel on its own, but if you have a fuel pump that is inline that isn't working you're potentially blocking the line. It can be bypassed and limped around, but i certainly wouldn't suggest it. You're gonna have to use your own discretion...

bluechrome

I drove My truck 4 2 weeks w/o an lp. It still rolled coal and set you back in your seat. My cp3 was fine accordding to john @ floor it

bluechrome

Vp truck won't run without incoming fuel pressure

j

looks like it will be sitting for a bit

rip 112

If you're gonna be driving short distances it should be fine, but I wouldn't take it on a day trip or anything, only when necessary. It can be done, but I wouldn't do it because it would eat at me, I just wouldn't be comfortable seeing anything other than 14-15psi.

homewrecker

Like I said before,cp-3's were originally designed to pull fuel on their on,no lift pump.I have ran mine several times with the Fass unplugged(by accident) with no problems.I towed 12k lbs for 70 miles before I noticed the fuel pressure gauge reading zero.There have been several other times I have ran the truck with the Fass unplugged.I wouldn't think twice about driving the truck with my Fass down.

XLR8R

The CP3 has an internal lift pump, so it can draw fuel directly from the tank (and through some auxiliary lift pumps, such as the OEM in-tank model).

Even though the engine runs fine w/o an external lift pump, the FCA's circuit priorities are changed enough to affect power production - especially with aftermarket fueling software.

Lrdchaos

^^^^^^^ There's the answer to your question.....

Asher

Not saying anyone's wrong or right because I don't have proof. BUT trust me, if the CP3 was designed to run without a lift pump then dodge would not have spent extra money putting on something that is not needed. If the lift pump is something that is not needed then why is everyone concerned about fuel pressure on the low side and installing these $$$$ aftermarket lift pumps???

I have seen a CP3 with the check ball blown out and case cracked, the conclusion was that the factory LP failed (pump was burnt out) and that caused the cp3 to malfunction and blow it's guts out.

AND

if the cp3 is OK to be used as a pull pump then why hasn't someone came up with a side of the road "quick fix kit" that would bypass the factory lp for the guys that have ones that leave them stranded???


Do what you want, but I would think your playing with fire if you drive it. I am pretty sure the cp3 is lubricated by fuel and if your not supplying enough lubircation to it I would guess the out come would be a shortened life pump (at best)...

I live in town and have rental car places pretty close to me that would rent me a car for about $10-15 a day, if it was me and you can do this, that is the route I would have to go. Better to eat your ego for a few days in a compact car then to push your truck later on...

Good luck and Merry Christmas!!!!

hemi5oh

Correct me if I'm wrong but a duramax uses a CP3 and no lift pump stock right? I think a lift pump is cheap insurance, but you should be fine.

homewrecker

Stock d-max's ran no lift pumps for the first couple year models with no issues.We're not saying go put everything on kill mode and drive it,just put it back to stock or something reasonable and drive.When factory lift pumps go out they restrict the fuel flow to the cp-3.The Airdog and Fass units with filters have a by-pass built in to allow fuel to flow in the event of failure so that you do not run into the problems as you described.

Asher

Gotcha, I wonder why someone hasn't come out with road side emergency kit to bypass the LP for those with a factory set up... it seems like it would be a great kit for the guys that aren't ready to drop the $$$$ for a expensive aftermarket set-up if the factory one is doing it's job...