PDA

View Full Version : Low Fuel Pressure



robertb6963
04-18-2007, 23:44
Hey guys and gals,

Just got the new injectors in today, put them in, and went to fire it up........and nothing. I cracked the #1 fuel line and cranked the motor, the fuel just dripped out. I had plenty of pressure when i parked the truck two months ago (i thought). IP maybe? The fuel lines were left out to the weather, but everything else wasn't(yea, not my brightest hour). Also, I have a 16gauge wire running from the positive post on the driverside battery with a plastic stem on the end of the wire that I don't know where it connects to. Very strange.

What sort of fuel line bleeding do I need to do on a 1994? I thought i read somewhere that the 94.5+ don't need to be bled.

Any ideas?

I can't wait to drive this truck (running well) for the first time!!!!!

Robyn
04-19-2007, 09:53
Make sure the electric pump is running when you crank it.

Also remove the black plastic cover over by the AC acumulator and there is a fuse unit on the far right side. Unplug the little fellow from its holder.
You will have a little device with a GM spade type fuse in it.
This is the fuel pump power fuse.
Touch the center of the fuse to the Plus+ stud in the box that is right close at hand. The fuel pump should take off and run as long as you have the connection.
Open the fuel filter bleed and run the pump until you have clean fuel coming out with no air. Use a small hose and run it into a can.
Go up front and do the same with the water drain until it runs clean and air free.
Now unhook the fuel delivery hose at the top of the IP and do it again until you have clean air free fuel.

You are now ready to go for a start.
What probably happened is with the injector lines open for so long the system probably drained back to the tank and is now full of air.

Once you have fuel to the IP its should go within a reasonable time.

Removing the Glow plugs to releave the compression can help get things up quickly. Takes all the load off the starter. Do it with the injector lines all connected and they will bleed out fine and as soon as the fuel mist is coming out the glow holes stop and reinstall the glow sticks and then it should pop right off.
It may still stumble and fidget around for a little while until al the air is out but should go for you.

Hope this helps

Robyn

simon
04-19-2007, 09:57
Check the liftpump for working, bleed filter tough port on top of filter if you have the round one,should have a steady stream of fuel.
After changing injectors you should attach the fuellines,and leave he nuts a couple of turns loose then crank the engine over till fuel appears at most of the connections. tighten the nuts and she should start.

JohnC
04-19-2007, 11:02
The injection pump will not develop any significant pressure without a sealed connection the the injector, especially if there is any air in the lines. The system is self bleeding once the pump has fuel at its inlet. A couple of 15 second cranking sessions ought to get it started, especially if you're already getting fuel to the injector lines.

robertb6963
04-19-2007, 11:36
Thanks so much everyone, yall are lifesavers!

a5150nut
04-19-2007, 19:09
Thanks so much everyone, yall are lifesavers!

So everyone here can be expecting a delivery of some REAL Texas BBQ in the very near future??? :rolleyes:

I'll take sliced with pickles and onions!