Engine/Transmission (1998.5 - 2002) New VP 44 problems.

[docterben]

Hey all, new guy here, massive problems. I'll try to be quick but this is drawn out. Need help. 99 stocker died on me, replaced lift pump, no start,no go. Pulled codes and got injector pump failure. Ordered VP44 from Southeast Power Systems (great shop, big help), got the updated 021 to replace my 015. Got the "300 HP" Bosch injectors from another source too. So now that everything is installed, it took us a whole day to get it to run. Bled everything 10 times but we weren't getting anything except from #4. Verified that the LP was at least pumping (havn't verified the pressure yet). Then we checked the return line relief valve, cleaned it again and pushed it in and out with a probe, and the thing started like it was supposed to. The problem now is that it idles rough, doesn't like to restart after overnight and... ... get this..... PRESSURIZES THE FUEL TANK!! Fuel leaked from under the cap and sprayed out when I opened it up!! There is constant vapor coming from the open filler neck and a gurgling sound that wasn't there before . The only thing I can think of is that the relief valve is bad, so I ordered one. Could the pressure be coming from the head return?? Help!

 

[tunod_68]

rough idle could be because of the injectors. not sure about the fuel tank. the cap should have a relief in it to aliviate that!

 

[docterben]

The tank has a so-called rollover valve on the top plate that is responsible for venting the tank... ... I'm told the cap has no venting. Truck ran perfectly before, never had this problem with any others (I have a 98 12 valve and a 95 too). I have to think it's something we did.