I am having trouble with my fuel line. I think I have a vacuum leak. My fuel gauge jumps around when I am in park, but put it in gear and it stops and holds steady tell I get in high then it starts again. called raptor they told me it sounds like a vacuum leak.
so my question is how do you find a vacuum leak?? the push lock at the pump looks ok comes apart easy, played with it when the motor is running don't seem to make any changes.
any help please..

Thanks Mike, MPCAMPERS

 

been doing some research,? can use 3/8 marine fuel lime to replace the old fuel line.??

thanks
and why marine fuel line...???

 

did you find the source of the leak or just give up and decide to replace it all?

 

I am giving up, I am going to replace it. ran my fuel tank almost dry, going at it tomorrow...!!! hope this will do it.??

 

UP DATE, AS PER RAPTOR SAYING I HAVE A VACUM LEAK, I DROPED THE TANK INSTALLED NEW LINE FROM THE TANK TO THE PUMP AND I STILL HAVE THE SAME PROBLEM. NOT A FUN JOB...!!!

NOT HAPPY..!!
ANY IDEAS WOULD BE GREAT.
I WILL BE CALLING RAPTOR...

 

I have no clue why the guy at raptor would say that, it does not sound at all like a vacuum leak. if you do not have a shrader valve setup with youre fuel pressure gauge it can cause this. i am just guessing that your lp is tied into the factory harness. the lp does not run at a constant voltage, its a pwm (pulse width modulation) circuit. the voltage is constantly changing, it happens to fast for you to properly watch without an o-scope. so to me this seems like a normal thing, maybe somebody else may have some inpput but this is my $0.02

 

I bet you issues are with their pump.

 

also a possibility, i had one and had issues with it. from what Jamie at CPP has told me it takes sending 5 out to get a good one to a customer

 

this is my second pump, it is working different then the first, not as bad as the first, I had the snubber valve and sending unit checked, and yes I am pluged in to the factory harness.? they are suppose to be plug and play? this Is not a good thing? I also heard it may take more then one to get a good one..

I took it 40 miles on the HW 70mph it stayed steady but as soon as I slowed it went nuts, what concerns me is it drops to 0 up to25 lbs some times, what is it doing to my VP. I have no clue what pwm is or how the change it

thanks for the input

I know one thing I don't ever want to drop that tank again...!!!

 

From what I have seen most of these things are plug and play across the aftermarket LP world. On my FASS it has a wireharness that runs about 3/4 length of the truck. It also mounts to the under the bed out of sight and runs 17-19psi depending on speed or petal position.

Id put your stocker back on and send them back the junk pump get your money back and add to it till you can get a FASS.