Hi guys, I've hit a dead end. I have a 1990 B2200 now it gets a little weird according to the wire diagram I'm suppose to have ground supplied from the I say PCM module to the fuel pump relay. but instead of ground when I have the ignition switched to position 2 I have 10 volts, but while I try to start the engine I have a upwards of 55 volts +. I've tried 3 PCM modules all same part number. new coil and ignition module for distributor. Is there some type of in line fuses for these trucks? Any help will be appreciated.

 

Welcome to the forum.

I am assuming that you have a 1990 EFI B2200 truck.......is this correct?

Where is the PCM located, that you have changed out? The reason I ask this is, some people change the Anti-Lock Brake module under the Driver's seat, thinking that it is the ECM for the engine.

Let us know please, thanks.

 

Mine is the carburetor. The module I replaced is on the passenger side inside cab. I’ll take some pictures soon. Thanks

 

Is your truck an automatic transmission truck? The manual trans trucks have a mechanical fuel pump mounted on the right side of the cylinder head (passenger side if in North America) near the rear of the head, and therefore do not have a fuel pump relay.

What is the actual issue with your truck? Does it not start? Does it start, but then shuts off? Can you NOT crank the engine over?

Let us know what you are having problems with so we can have a better idea of what is actually going on with it.

Thanks.