So I posted last week about my Airdog II losing prime and not knowing whether or not it fried my fuel pump. We got the lift pump to prime again, but there's still not any fuel coming out of the fuel pump. I've been trying to find anything else that could be wrong besides the fuel pump being shot, but keep coming up with nothing. I just hooked it up to a code reader and had a code for Cruise Control Switch - High Voltage, and then a P1693 code. I know it's a companion code for something else, but there were no other codes. If the vp was shot wouldn't there def be a code? And if the timing was off, would there be one for that too?

 

Mine never threw a code, my VP just went out.

 

are you wondering about your fuel pump or the VP...Have you cracked any injector lines and cranked the motor over to see if it was pumping fuel to the injectors?

 

The vp is the fuel pump. I wasn't talking about the lift pump if that's what you're thinkin. Yes I did crack the injector lines and there isn't any fuel coming out of the vp/fuel pump. But since there were no codes sayin my pump went out, I've been trying to find anything else that could be the cause.

 

To Clarify. Injection pump is the VP44, Lift pump/fuel pump is what pumps fuel to the injection pump.

is there fuel being pumped to the IP

 

What is your fuel pressure from your lift pump to the Injection Pump?

If your AirDog is loosing prime, then you may have to replace the VP-44 if you are not getting any fuel out of it.

When was the last time that you changed the fuel filter?

While you have the fuel filter out, bump the starter and see if you have fuel running into the fuel filter housing. If you do, then you need to see what your fuel pressure is.

Here is a link for troubleshooting your truck. Try this and see what happens.

 

My vp going out shouldn't affect the Airdog losing prime. If the injection pump goes out the lines from the lift pump going up to it should still be full of fuel. I changed the fuel filter about 3 weeks before I put the Airdog on but it doesnt make a difference because the Airdog has its own filtration system. I did get the Airdog to prime itself again but I've already got that figured out. Does anybody wanna answer my questions about the codes?

 

VP doesn't always through codes

 

Haha sorry you had to post that a second time, but ya that's what I've been hearin.

 

Geno's garage on this site has a walk through DX for VP44 injection pumps. Check it out.