Alright, so it's been a while since I've driven my 94 k1500 since I've been away for the past 8 months. I started driving it last week and on my way home it died on me. Didn't sputter or misfire or anything like that, just flat out died. I pushed it off the main road and sat in a parking lot for a while waiting for my dad to meet me so we could tow it to my house. I tried to start it and it started right up and I drove it home.

Initially I thought it was the fuel pump, so I put a pressure tester on it and it is getting 14psi at the throttle body. It died while I was testing it and even when cranking it still gets 14 psi.

I took a plug out to check for spark and it is getting spark and actually started with out the one plug in. It has a MSD 6A ignition amplifier and MSD coil, as well as a cap and rotor and wires that are less than a year old.

While driving again it almost died, but this time had somewhat of a backfire and kept running. About a mile down the road it died as I was getting to a stop sign. I tried starting about 4 times and it started.

I am getting two codes:

#33-MAP sensor circuit error (signal high indicating low vacuum)
it's been throwing this code for over a year now and I haven't really had much trouble with it.

#54(Fuel pump circuit low voltage)
this is obviously the one that's the issue but I'm not sure what would be causing it if the pump is making good pressure. Could the fuel pump relay be going bad?

One thing I'm not ruling out is the ignition amplifier. It is older than the rest of the ignition system and could have gotten wet or been damaged by vibrations.

Any thoughts?

 

I would go after the pickup module in the distributor. Fuel pump relay could be going bad but you should see the gauge die off so i would think that it is not the problem. My pickup would kill my one truck when it got warm, and once it cooled off it would fire back up again. And it did all kinds of strange things before it died, lol.

Even the reluctor wheel on the distributor itself could be falling apart, TBI truck distributors aren't known to be really great.

I would still change the fuel pump relay and see if the code clears.

 

Yeah, I'm gonna go do the relay right now. It's easy and a $10 part. We'll see how it does.

 

Is there a way to test if the distributor is the problem?

 

Um, well you can look at the reluctor wheel on the shaft. If it's cracked and all shitty looking it's probably not helping anything. The pickup module in the distribtor does generally set a code though, however not always.

A timing light will show if it is firing consistently. And I think you can ohm the pickup module but I don't know the values offhand. Outfits like autozone can test it too. And you can google the proper readings.

 

Ended up being the ignition amplifier. I had it hard mounted to the inner fender with no isolator or buffer. I just went back to the stock setup. Thanks for the help.