Engine/Transmission (1998.5 - 2002) How often can the overflow check valve go bad?

[BWagnaar]

So lately I have been having the most horible time starting my freaking truck. I can't find fuel leaks, there are no code, and i've been trying all kinds of things to get it started. What seems to works the most was to loosen the overflow valve, bump the starter, and then tighten it while the pumps were running. This might get it start, i also have to crack the injector line to bleed out the system. Sometimes it bleeds easy, but most of the time i can't get the line to bleed (takes an hour or so sometimes). I replaced the overflow vavle about a year ago, but because the vp kept losing its prime i bought another one and replaced it last night. The truck started and then i shut it off. I tried to start it again but it had to crank for a few seconds before it fired upped. I started a couple of times, it seemed to be fixed, but it still took a few seconds to start. So we went to dinner, tried to leave the place and the truck wont start... . Back to square one. After half an hour of cranking and bleeding and cursing it fired up. Got it home and tried to re-start... nothing wont start.



So i'm wondering how long do overflow valve usually last and what breaks them?



I'm at the point were i wish someone would steal the truck so i can get insurance money... . but then again how will they drive off:{



The was also the horrible thought of actually taking it to do the dealer... .

 

[georgej]

BW



You said pumps so I'm guessing your running an additional pump to your stock one? If the pressure to the VP is more than 18lbs or so it causes hard starting on some of them. The extra one can be wired to turn on with an oil pressure sensor.

 

[MRose]

After installing my FASS I had hard start issues. I had to wire a hobbs switch to the oil pressure boss on the oil filter pad. That worked for about a year and then I ruptured the diaphram in the VP-44 and had your symptoms. Had to blow out the overflow/replace it, it would then restart one or two times then the same hard start. Started carrying ether with me to start it. No codes and was fine when it started. A symptom was the fuel pressure would drop to 0 instantly when I shut it off. Unplug your lift pump and try starting it. If it fires right up wire a hobbs switch, if it doesen't time for a new VP44.

 

[BWagnaar]

I've heard of the hard starting with high fuel pressure, but i usually wait a secind or two before i start the truck, by that time the fuel pressure has dropped back down to zero. While crankning the fuel pressure flutters between 7 and 13 psi.



MRose, thanks for shinning some new light on the issue. My fuel pressure does drop to 0 instantly. If i crack the overflow valve and bleed it usually wants to start more often. Once i can get the system bled i notice the fuel system stays pressurized a bit more when the pumps shut off.



What the diaphram do in the VP? Are there some other ways to diagnose the diaprham?



Thanks

 

[BWagnaar]

This is so frustrating, i just replaced the fuel filter this morning and the truck started and stopped fine. It would hold fuel pressure for about 5-8 seconds were as before when the pumps stopped it would slam back down to zero. I started and stopped the truck about 4-5 times letting it run for different amounts each time ( just randomly) and the truck started fine each time. So we drive into town and when we go to leave it wont start. I try all the tricks and it still dont start. It frustrating that it doesn't set any codes. I'll probably just throw a VP at it...

 

[rkressg]

Check the T-Fitting at the back of the fuel return line. It could be letting air in when you shut the truck off.

Have you noticed any correlation between which way the truck is facing when it is turned off (I. E. facing up hill or down hill)?

It can be the Check Valve inside the VP44 that is letting air out.

 

[DWest]

If I park my truck facing uphill it will take longer to start, down hill and it fires right up. If I kick the starter to prime it for a few seconds then it fires right up. Should I look for a fuel leak or is this the diaphram in the pump? DW

 

[BWagnaar]

The truck is always parked on level ground. It starts right up when it sits for more than 8-10 hours. Its starts like nothing is wrong, but than if you drive it and then try to re-start it... it wont.

 

[rkressg]

The truck is always parked on level ground. It starts right up when it sits for more than 8-10 hours. Its starts like nothing is wrong, but than if you drive it and then try to re-start it... it wont.

This is a classic sign of a failing vp44.