97 blazer starts then stops, new fuel pump, new problem

[MT-2500]

Originally Posted by old_master

Thank you for your efforts! I stand corrected on the redundant circuitry. Seems like a rather foolish move on GM's part to one: program the ECM to override the OPSU and two: leave the wiring and switch in place raising the cost of the vehicle. Oh well, I suppose they've done other foolish things too.
Thanks, OM

10-4 on that GM ideas old_master.
GM ideas are hard to figure out sometimes. On the newer 00 up models they are doing away with the oil pressure switch for fuel pump.
Also A lot of even older cars are leaving the nut off of the front of the air condition compresser to save a nickle.
Mt

[MT-2500]

Originally Posted by blazee

I don't think so. It would have to be something that's internal to the ECM and not shown on the schematics. It would also have to be something that changed at some point because I know some guys have pulled theirs and the engine didn't die.

Blazee
Thanks for the after dark testing and letting us know what you found.
It does make you wonder about that oil pressure switch.
If it was working right it should has keep power going to the fuel pump.
MT

[BlazerLT]

Wy aren't we considering the ignition switch?

It is a common occurence on a 1997 and would cause this problem.

[Brian R.]

From the original post, it appears that replacing the fuel pump solved the problem - for 18 months - and not this time...

Maybe the original poster is not clear in stating what solves the problem, what caused him to replace the fp the first time, or if the pump solved this problem the first time. funkamongus20 please clarify.

[blazee]

Originally Posted by BlazerLT

Wy aren't we considering the ignition switch?

It is a common occurence on a 1997 and would cause this problem.

Nobody's ruling anything out. We were merely discussing the operation of the fuel pump circuitry. There are several things that it could be, including the ignition switch or even a malfunctioning security system. Like Brian said, we really need more info.

[BlazerLT]

Yea, you are right, too bad the guy posted his question and left.

Until he returns I guess there is no point in really going in either direction.

[Brian R.]

The guy is probably too busy at his local part store buying another fuel pump, a oil pressure sender, a fuel pump relay, an ECM, a wiring harness, and an ignition switch.

And now he comes back and goes out for a new security system.

[BlazerLT]

lol, maybe he is at the bank securing a loan?

[old_master]

It was a pretty in-depth discussion! Maybe we baffled him and he's out buying a new vehicle! Might be a less expensive alternative when you figure in all those parts. I learned something from this thanks to MT-2500 and Blazee. Learned GM makes some crazy choices. Just when you think you have the answer, they change the question.

[Brian R.]

When you look up "crazy choices" in the dictionary, you see a Ford emblem....

[blazee]

Originally Posted by Brian R.

The guy is probably too busy at his local part store buying another fuel pump, a oil pressure sender, a fuel pump relay, an ECM, a wiring harness, and an ignition switch.

And now he comes back and goes out for a new security system.

It's a good thing that I didn't mention a plugged cat or a bad ECT sending unit.


EDIT: Oops

[Jeremy Fitch]

I took the liberty of testing to see if mine would stay running when I pulled my fuel pump relay, and it did say running. Just a FYI.