Some May recall my previous problem with my Fuel pressure. Initially the thought was air in the lines. But now I think it's something to do with the air dog pump block area itself. It still could be a house in this area,i dunno. What I do know, is that the problem is stemming from this area.

 

Last night after work, I killed the batteries trying to get the truck to crank over. Luckily I had a guy to jump me.

 

On the first startup of the day, it cranks over no problem. Sits afterwards, then it becomes a problem. This has happened a few nights in a row now. But not bad enough like Last night.

 

I'll bump the starter to get the pump to cycle, and I can distinctly hear a whirring noise like it's not primed. But maybe after a few bumps it'll prime and the whir noise goes away, the pump changes in sound and Fuel pressure goes back up.

 

Mind you I get about 17psi, when it's not sounding primed. But when it gets primed, 20 to 22psi. I'm at a loss here, and tried calling air dog But they didn't answer. Probably called too late...

 

Any idea what it is? Could the fittings to the pump block be bad? If it happens again tonight, I'll record video of it to try and get it.

Its still a air leak issue. I seen the brief lag of the pressure at key on. I would consider finishing your line project then check all other seals like the o-ring on connector tubes and any remain banjo bolts seals.

I have the fuel supply line hooked up directly to the vp44, I got rid of the oem filter canister.

 

I'm going to call Eric Monday and get it done. I'm tired of this. I'm really hoping that I don't have to replace the crossover o rings.

 

The guys at the local diesel shop were nice and helpful, but they didn't have the parts on hand.

Edited June 19, 20168 yr by hex0rz

Try not to get too frustrated. These fuel leaks are a PITA to find, and once you get it fixed you'll say to yourself 'man I wish I could've found that sooner!' because more then likely it's going to be something minor and just got overlooked until fixed. You'll get the leak found!

I have a problem with dwelling on it if I spend money on something that I didn't need to spend on because it wasn't broke in the first place! ?

 

I'm just cussing out air dog. I guess I should have gotten a fass, system...

AirDog pump are fine now its just there crappy plumbing solutions with the quick connects. FASS I like the plumbing but hate the huge size of the pump very difficult to hide.

Eric has the adapters to rid the AD of the quick connects. He also set me up so that I could put in the old oem pump if needed to get me home..

 

He told me I need to get rid of the quick connects and rid myself of headaches before I ever installed the Air Dog pump. If anyone wants them I have them still new in the box.

 

 Wondering if you could hook up 5 pounds of air pressure to the fuel line down by the tank then go around with a spray bottle of soapy water to find the leaks with bubbles.??

Edited June 19, 20168 yr by JAG1

Show look like this when done... All Parker Push Lock and JIC fittings.

 

Got around to doing the bucket test last night. It passed the test. So now I'm trying to figure out where else it could be. Tried to talk to Eric but as soon as i came into the building at work i lost him. Going to try him again tomorrow. 

 

Anyone have ideas? Could it be the air water separator is plugged?

Ok just to clarify, when doing the bucket test you pulled the suction and return lines from the tank side and put them in the bucket right? And with it like that the truck started right up?

 

If that's the case then your issue is in your fuel module. Are you running a drawstraw or sump? If not it seems as though you've found your problem since doing the bucket test eliminates the fuel module out of the equation.

Suction and return line in bucket...

 

Truck would not start like normal. Still going to have to hunt down the problem. 

Ah ok, so then the opposite of what I said. Fuel module checks good if that's the case. Have you tried pointing the nose of the truck downhill and letting it sit over night and then starting?

 

Also try hot wiring your lift pump to see if that'll start it. You could try pulling the lift pump fuse and seeing if the truck still starts. If that's a no go, try adding a relay to delay pumping until after the truck starts? Just spit balling here because I can't remember everything you've tried so far but it seems like there's either a leak in your return lines at the back of the head or at the fuel T, or your VPs not happy with the cranking pressure.

I don't have any inclines around me to utilize. 

 

I talked to Eric at Vulcan performance. He said my next step is to call air dog. I'm going to see what they have to say first then go from there. Also going to put a new water separator in. 

So i dug a little deeper into my fuel problem. I was googling up on the issue and some guys reported that the injection pump hard lines could be the problem. They were saying to Polish up the ends that mate with the crossover tubes. 

 

I removed the hard lines and polished up all the mating ends. A couple of them looked pretty rough. The crossover tubes were pretty good. I was wishing i also had o rings at the time too, but what can you do sometimes. 

 

I dunno if it will really solve my problem or not but it will be one less thing to eliminate...

 

I'll know more later as time goes on to see how the truck reacts. 

Sometimes that's what it takes ya know. Just slowly chip away at all the potential issues and it only narrows the possibilities to what's actually wrong! 

Called air dog, told me to check the regulator. I pulled it and didn't see anything out of place. Going to call them again and see what to do next. 

 

The hard lines were not the problem. Still having issues. 

Edited July 26, 20168 yr by hex0rz

Ugh, i dunno what to say. I haven't done much since doing the hard lines. Just been living with the problem. Been dealing with other repairs. As i was about to leave o'reillys, the truck wouldn't start. I could tell during the cranking that something felt different like a gas engine without it's spark plugs in. 

 

The day this occurred, it was almost 100 degrees out. I let the truck sit for a few minutes then tried again. This time it kind of sputtered over instead of a nice firm firing.

 

Hasn't done it since but i just dunno. Maybe my vp44 is on its last leg? It's not throwing codes, but that don't mean anything always...

 

Im thinking more and more about the p pump conversion!

 

 

Anyone know if i can substitute the crossover tube o rings with regular o rings or are they specific? Is hate to buy regular o rings that are marked up because i had to order from cummins. Anyone know the size as well?

 

Last night i found a parking spot at work that had a slight incline. The truck started on the first cranking but i also cranked for 5 seconds or so. Dunno if it was a clue to my problem or not. 

Edited August 2, 20168 yr by hex0rz

Sounds almost identical to what mine will do.

So does that mean I'm joining you in the can't fix the mystery club or do you have a solution. 

Well I haven't changed crossover tubes o-rings, or injector o-rings, both which can cause leaking of fuel back through the return lines and making the hard starts. 

 

For now what's seemed to work for me is to start the truck right after the initial lift pump prime and it lights right off. Could just be coo insistence though.