I Bypassed My Lift Pump 2001 Diesel, I Left Wire Connector Off And Ran New Pump Direct To Battery, Now No Fuel To Injector Lines, Does Leaving Wire Connector Open Cause The Truck To Think There Is No Fuel Therefore Not Allowing Stop Swith On Main Pump To Stay Closed?

 

I don't think so. If you have pressure to the vp it sould start. check the codes with the key, and tell us a little more history on your problem. Was it running when you put the new lift pump on?

 

Thanks for replying, I got it started after loosening 3 injector lines. After starting I watched my gauge that I have mounted on fuel pump test port, pressure was dropping as it was running, when I accelerated the engine to 2000 rpm the pressure dropped to 3 lbs, I guess my cheap fix is not going to work. Does the bypass valve give much trouble, I read in manual that it is supposed to open after 14 lbs. My original pump was only reading about 4 lbs pressure when at 2000.rpm. I have this pump direct to battery , so my original question was answered, it will run with wire harness unplugged from pump.

 

was your old pump not working at all? you can run your new pump and OEM pump togeather and it works well. that's the way I have it, and get 25 psi. I dont know about the bypass (when it opens) but I don't think it works as open or closed, it lets some fuel back at all times (more if the truck is at idle and less at WOT)

 

My old pump was working, but only showed 4 lbs. at 2000 rpm and about 6 lbs at idle. Is there supposed to be a pump in fuel tank also?

 

no pump in the tank.... unless the dealer retro fit one there. That's where they put them if they replace them as of about a year age. If yours was on the block then there's not one in the tank. you would be suprized how much pressure you would have if you plumbed back in that weak pump. If that's a holley blue pump you put on there you can take out the spring and stretch it and get more pressure

 

I think it is a carter pump, I took it apart and the vanes and ring looked a little wore.