I recently got my much needed gauges and hooked up fuel pressure first to check things out. When i bumped the starter for the 25 second run, it jumped to 24 and slowly increased all the way up to 26! Does this sound like a return line restriction? I have an adjustable overflow valve that is preset at 14 psi. What could be going on here? I think this is the cause of my rough running truck...

Does your airdog have adjustable fuel pressure?

I beleive it does. Its the new Airdog II 4g system and the sump kit. I just put that on there. I haven't messed with it.

Adjust your pressure down.

That had helped a bit actually. It must have been set for a 12 valve because it says on their website that a 24 valve is preset to 15-17 but it was 24-26. The pump is no longer whining...or dead heading my pump. Thanks Me I totally forgot it was adjustable

 

You are welcome glad it was an easy fix.

5 hours ago, Cumminz said:

I recently got my much needed gauges and hooked up fuel pressure first to check things out. When i bumped the starter for the 25 second run, it jumped to 24 and slowly increased all the way up to 26! Does this sound like a return line restriction? I have an adjustable overflow valve that is preset at 14 psi. What could be going on here? I think this is the cause of my rough running truck...

 

DONT adjust that valve.....!  Not sure why anyone thought this was a good idea to market.   Matter of fact, I'd suggest throwing it away and replacing with a factory Bosch overflow valve thats NOT adjustable.

I didn't even know an adjustable overflow valve for the VP was a thing! 

10 hours ago, KATOOM said:

 

DONT adjust that valve.....!  Not sure why anyone thought this was a good idea to market.   Matter of fact, I'd suggest throwing it away and replacing with a factory Bosch overflow valve thats NOT adjustable.

 

Agreed. I would go back to Bosch OE overflow valve. The never fail I've got 12 years on mine and 220k miles still going fine. The fuel pressure of the AirDog is the important thing than overflow valve.

I still have the original I can swap it out in like 20 seconds. lol. Anyhow, I adjusted the lift pump pressure and has stopped the whining noise so thats a plus. I was hoping that would solve my erratic rpms that happen throughout the throttle range but it didn't...That's probably for a different thread....

 

Anyone want to buy an adjustable overflow valve? lmfao

Edited October 16, 20168 yr by Cumminz

Yes, different topic.   I'll look for that thread.