FASS not working but truck runs.

[jnelson]

FASS is not working. Cant here it, no return fuel to tank, but she starts and runs. Changed the water seperator out, and she still started and runs. Put it on level three and ran around the block, ran fine.

How?

 

[jnelson]

Found an inline fuse that was burnt out. Might have burnt out when we had our flooding rains a few weeks back.

At least I know my truck will run, even if the FASS doesn't.

 

[wtfd6]

I would like to know how that worked too.

 

[nickleinonen]

cp3 will draw fuel into itself as long as the restriction isn't too high [dmax lly/lb7 engines cp3's had no lift pumps, i think the new ones might?] it might start to sputter under heavy load at higher rpm, but a hpcr will run with no lift pump

 

[WUnderwood]

I am lost.

So the fuse that was burnt out wasn't the problem? The FASS still doesnt run?

 

[Cochran]

will idling without a lift pump for 10 minute intervals damage the cp3? I have a remote start that does not power the fass. I could find something with power to trigger a relay if absolutly necessary. but the fass pump fires up as soon as I turn the key.

 

[hotram03]

The FASS has a built in bypass port in case of failure to allow the CP-3 to suction syphon past it, from my understanding it want allow any heavy draw on it like in a racing situation, but if it quit out on the road, you will be able to get it home, driving normal. No the CP-3 want burn up at idle with the FASS not working, there again the bypass is in effect, now I wouldn't go and drive it all over the place I would get it fixed, someone correct me if I'm wrong, my 2c.....

 

[steved]

The FASS has a built in bypass port in case of failure to allow the CP-3 to suction syphon past it, from my understanding it want allow any heavy draw on it like in a racing situation, but if it quit out on the road, you will be able to get it home, driving normal. No the CP-3 want burn up at idle with the FASS not working, there again the bypass is in effect, now I wouldn't go and drive it all over the place I would get it fixed, someone correct me if I'm wrong, my 2c.....

This is how I understand it as well... the fact the Duramax uses the same pump without a lift pump sorta makes me feel a little better about doing it...



steved

 

[jnelson]

I am lost.

So the fuse that was burnt out wasn't the problem? The FASS still doesnt run?

Replaced the fuse and she's humming like a kitten.

 

[JEstes]

This brings up a good question: Could I take a D-max CP-3 and bolt it onto the Cummins or does it mount differently?

 

[RobertP]

i know on my own personal experiance, that i left my fass unplugged one time and drove over 100 miles to a dyno event, beating on the truck the whole way. i never felt or saw anything different than normal. im still running that same stock CP3 now with not ill effects.

 

[jnelson]

I believe my pump has been out for a while. I filled up at the truck stop before I left and left my truck running. It should have spewed out all over the place with the return fuel and the high volume filler nozzle ( it has in the past). So I usually trun my truck off, but on this last trip I didnt. Not to mention the fuse looked like it burned out a month ago. Then I pulled a 3512 CAT (15,000 lbs) all the way to Tulsa then to Oklahoma City, and all the way back. I never knew it wasnt working. EGT's getting to 1300 and engine temps to 230 and the truck never missed a beat.

https://www.turbodieselregister.com/photopost/showphoto.php/photo/1874/ppuser/15085

 

[LowFly]

FASS is not working. Cant here it, no return fuel to tank, but she starts and runs. Changed the water seperator out, and she still started and runs. Put it on level three and ran around the block, ran fine.



How?

We have a by-pass built into the pump so if the FASS motor does stop for some reason, it will not restrict the filtered flow and the truck will still run to get home. CP3 trucks are fine with low to no pressure as long as you keep it easy and keep the boxes off. Even then, i dont think you would hurt them, just would run out of fuel.....