Here are a few minor issues that have been bugging me about my truck lately.

Randomly, the "Rear Anti-Lock" and "E-Brake" lights come on simultaneously, thought it was just the sensor (in the differential) so I replaced it with a supposedly brand new one from Autozone. Problem still occurs.

Randomly, I have to bleed my fuel system to get the truck to crank. For example I came back out of the grocery store the other day and the truck just wouldn't fire up. I had to do what I always do by removing the rubber line that runs to the top of the IP, turn my key on (its got an electric pump on the frame rail with the mechanical pump delete) and wait for fuel to start spitting out of the line, I quickly reconnect it to the top of the IP then crank up the truck. This just started recently and it is a pain in the *** when it happens.

Randomly, my water in fuel light comes on, every now and then it will flicker in and out but it stays fully lit most of the time. This started happening a few months ago, but I was told that it probably was just the sensor so I ignored it. The truck feels fine and seems to hold a steady idle. I'm not sure if this is related to ^^that^^ previous issue or not, but it is annoying.

Last but certainly not least, I have a low / high idle issue. A couple months ago I took my truck on a road trip to Panama City for spring break (12 hour trip one way). We stopped at a gas station about halfway into the trip, went to back into a parking spot and the truck died. Cranked right back up just fine. I found that if I ran the rpm's up to around 2000, then removed my foot, the truck would drop down to the usual 600 ish, sputter for about half a second, then die again. I have temporarily fixed this particular issue by manually increasing the idle a few hundred rpm's. Now when I rev it up and remove my foot, it doesn't die. However, now my low and high idle limiters (or whatever they're called) are no longer there. Even when the engine is cold it will idle around 900 rpm, same as hot. Not sure if this issue is related to any of the previous ones or not, just hoping its not the IP itself haha.

Any and all comments will be greatly appreciated, thanks.

 

Sounds like the sensor for the HPCA might have come off, that for the high / cold idle. Two prong sensor behind thermostat housing.

As far as dieing when letting suddenly off the throttle, sounds like the metering valve is sticking, or so i hear. Fill the FF with diesel clean or atf fire it up till it gets in the IP, lines injectors (you can hear the difference) and shut it off, let it set that way of a night.

Ive heard the water in fuel light can come on when sensing air, also, could be a vacuum between the FF and IP (IP starving for fuel) Verify that there is not water in fuel. Then check to see that the FF is clean and clear, and that the lift pump is supplying adequate fuel.

The ABS light may not be the sensor, could be the pigtail from the sensor. They like to get mud and stuff caked around them and break the wires, might be something to check.

Last but not least, having to bleed it after it sets means youre getting air in the system, that being said your electric pump should purge the air, but is not. After checking its flow / pressure, check the IP fuel shutoff solenoid.

 

If the brake lights come on at the same time, Your master cylinder could be low aswell, either a leak or time for brakes!

The fuel light as he just said could also have some air issues aswell, I would say to bypass your water seperator and try it, That fixed 3/4 of my problems, Now I just have to redo the glow plugs and do the return line/top hat kit.

 

The 91 doesn't have a stand alone water seperator, but that definitely was a problem area on the early trucks..

 

Ah good call, They were intergrated by then