montana_28

So here's where I'm at... batteries are good... tested for spark and that's good... changed out the fuel pump relay under the hood. I've had NO other problems up until now. It started fine in the morning and then when we went to leave the store we were at... nothing. It will turn over with no problems. Is there anything else I can check before I have to drop the fuel tank on this thing???? Thanks in advance for the input!


MT

DomesticFan

have you checked for fuel pressureat the injector rails? Fuel Fiter?

monteash

Is it TBI? If it is you can see the injectors spraying (or not) and get the answer you need about fuel pressure and the fuel pump.

Before you drop the fuel tank, consider cutting a hatch into the floor above the tank to access the fuel pump assembly. I did this on a 1991 model and it saved me hours on a fuel pump replacement. You have to brace the section you cut out when you screw it back in. Use some RTV and metal backed tape to seal the gap made by the cut.

This really saves time when you have to replace the pump again. I even thought about putting hinges on the hatch but didn't have the time or ambition.

Hope this got to you before you had to make repairs.

Good luck,

Monte

1981camaroz28

It should be Trotle Body yes crank it and see if gas is comming out.

MalibuMaxxSS

nice trick, seen this done lots on Jeeps as I did on mine, did not know you could do it on burbans....coo

Suburbanite

If your vehicle is turning over and starting briefly and then dying, it could also be a malfunction with the Passlock feature. I had this same problem in a '99 4wd 1500.

Passlock is a theft deterrent system that, in brief, is designed to keep somebody from putting a screwdriver in your ignition lock, turning it, starting the vehicle, and taking off. At a simple level, here's how it works: Inside the ignition lock cylinder are some sensors. When your key turns the sensors, they generate a resistance code that is read by the computer.There is another password that then gets passed to the powertrain control. So, while you're cranking the engine, and the engine turns over, if the powertrain control doesn't see the password in a certain period of time, it disables the fuel injectors.

It happened to me intermittently, but seemed to be related to leaving the vehicle outside overnight, or having the vehicle in humid climates. The way to tell if it's the Passlock feature is to look in the upper right of the instrument panel after you try to start it and it dies. If the Security light is lit, your Passlock feature has activated. You can cause it to reset by leaving the ignition on (turn the headlights off) for a period of time--the Security light will go off. You can also have somebody hook up a computer and see if the Theft Deterrent system code is activated.

The first step in fixing it is to have the ignition cylinder (the entire unit) replaced. The next piece is the Passlock Control Module. Good luck.