Sorry, I didn`t mention, I did those things first. On the wiring diagram I have for this truck, the gray wire supplies the hot to the fuel pump. There is nothing at the pump, (on the tank), but, at times, I`ll turnthe key on and here the pump come on and then it will start and run for a few minutes. You can here the change in the way it is running just before it konks out. Then when you turn key on there`s no electric at the pump. This has happened several times. Possibly a ground?
One ground is on the roght side of the engine, make sure it's clean and the other is on theleft side of frame rail. But check your relay as well it may bebad. Also check the fuel pump pressure. It shold be 41-47 psi.
February, 4, 2011 AT 11:36 PM
It really doesn t start often enough to get a pressure reading. My problem is no electric to the pump. I ve checked the ground and it is good. I don t have any juice to any terminal on the relay, with the key in the off or on position but, I do have juice to the ECM fuse which, on my wiring diagram, supplies the relay with power. Could it be in the fuse box itself?
February, 5, 2011 AT 12:10 AM
Check your dark green wire coming out of the pcm. That supplies power to the fuel pump relay. Then if it 's got power then check the relay, same color. On the pcm it's nmuber 8 wire marked on the connector. This could also be a anti theft problem. If your security light is blinking you need to reset it as it will cut power to the fuel as well as ignition. These can all be bad connections as well causing your problem they can be at the pcm/relay, etc. Make sure your fuse is good, just pull it out and puut it back in or you can jump it to see if that give you power to the relay. But don't leave it in long like that. The fuse you are talking about is ecm b.