I thought I better start a new thread because my problem was not related to high oil pressure.

http://www.dieselplace.com/forum/showthread.php?t=337882&page=2

You can view what I've done up till now there.

I was testing the LP with a digital volt meter when all of a sudden the engine revved up on it's own and died. I went in to restart and there were no check engine or wait to start lights (buld check or when cranking) I tried doing a diagnostic, nothing. I tried checking the fuse, it was good.

So what could have caused that and how do I fix it? Please help as fast as you can! I am needing my truck badly!

Any ideas??

Did it restart?

What did you probe when you test the voltage?

Did you test it with the engine running?

ECM-B fuse is blown?

Did it restart?

What did you probe when you test the voltage?

Did you test it with the engine running?

ECM-B fuse is blown?
I used a digital voltmeter and I unplugged the lift pump and tested the plug that wasn't connected to the lift pump (obviously) the truck was running. It revved high for 3-5 seconds and then died. I can't get it restarted, no check engine light or wait to start lights up anytime, even during bulb check.

I thought the ECM fuse would be the best idea, because it makes sense. I checked all the fuses by the driver's door, are there more somewhere?

I thought the ECM fuse would be the best idea, because it makes sense. I checked all the fuses by the driver's door, are there more somewhere?

Did you check all the fuses in the black box under the hood on the drivers side?

YAY!!! It was the ECM-B fuse! The manual didn't say anything about ones under the hood.

In the meantime of trying to figure out about the ECM, I replaced the OPS. When I put in the new fuse, LIGHTS! I've never been so happy to see a check engine light!

It started right up and ran really well. Now my oil pressure is where it's supposed to be ~50! I'm super exited!

Do you think it hurt the injection pump? How long would you have to run no lift pump to have damage?

YAY!!! It was the ECM-B fuse! The manual didn't say anything about ones under the hood.

In the meantime of trying to figure out about the ECM, I replaced the OPS. When I put in the new fuse, LIGHTS! I've never been so happy to see a check engine light!

It started right up and ran really well. Now my oil pressure is where it's supposed to be ~50! I'm super exited!

Do you think it hurt the injection pump? How long would you have to run no lift pump to have damage?

As long as your truck is running I would say your IP is good. Running without a LP can shorten the life of the Injection pump, but you shouldn't worry (it takes a while to wear the IP out under normal operation)... If a truck could not run at all without a lift pump helping then that is signs that the Injection pump is worn and may need replaced soon.

Don't do it when engine is running. Don't ask me how I know it.

You can put the ign to on but not running and probe the voltage.

However, it can show good voltage but not enough amp anyway so it is still not a definitive test.

If you want to check LP voltage on a 94-95, with it running, use your meter on pin G of the OBD1 port, its the bottom left. That shows the LP voltage supplied by the OPS.

When my OPS was failing it showed a drop in voltage, and LP would stop working below 10V.

If you want to check LP voltage on a 94-95, with it running, use your meter on pin G of the OBD1 port, its the bottom left. That shows the LP voltage supplied by the OPS.

When my OPS was failing it showed a drop in voltage, and LP would stop working below 10V.
Thanks for the tip! I'll try that next time instead of frying my fuse! :P

If you want to check LP voltage on a 94-95, with it running, use your meter on pin G of the OBD1 port, its the bottom left. That shows the LP voltage supplied by the OPS.

When my OPS was failing it showed a drop in voltage, and LP would stop working below 10V.

For 1993 this pin G OBD 1 wire goes to the fuel pump relay.

I believe it is the same for 1993, the OPS voltage on pin G.