Engine woes

[booneylander]

Well it seems I got a bad one.

Bought the truck almost a year ago and have managed to drive it only a couple times.

In the first few hundred km's my Getrag disassembled itself. After replacing with a good used unit, the truck almost made it to the end of the test drive before an axle tried to go for a walk on me. The rebuilt axle let me drive the truck a few hundred km's more, but now this is my issue:

Engine kept getting harder to start, seemed like it was starved for fuel, because if I cranked it long enough it would fire. Usually once it had been running for a while and was warm everything was fine, but then it started to be hard to start even after just a brief shut-off.

Then it just quit wanting to start at all. So I got it going by starting it on ether, with the intake heater disconnected, and drove it home.

I installed an electric lift pump and bypassed the stock mechanical one, new fuel filter. Truck still wouldn't start. I though it might just be a matter of an air bubble somewhere so I started the truck on ether again and ran it for a bit. Cracked each injector and made sure fuel came out. Shut it off. Still wouldn't start.

Thinking maybe it could be something funny happening the with FSS I put 12V to it and heard a nice solid click. Tried powering it directly and no luck. I didn't pull it out yet though to see if I lost the rubber nub on the end or something like that?

I got it started again on ether because I needed to use the truck so I figured I could just run it and not shut it off then work on it some more later but this time it wouldn't really idle. I could start it and it sounded nice, would get a small puff of white-ish blue-ish smoke. Would rev up ok. Then if I let it sit and idle it would idle for a bit (maybe 45 seconds) then it would start to slow down like it was under load, and eventually stall. If I caught it slowing, and got on the accelerator, it would kind of rev up for a bit, then slowly it would clear it's throat, and roar back to life like a champ, and a big cloud of the white-ish blue-ish smoke would come out again. It smelled like unburnt fuel, not like coolant. Then as soon as I would leave it, it would start to bog down again and the same thing would happen, until it eventually just died. I never made it out of the driveway.

I pulled out the cold-weather timing advancer solenoid thinking maybe it was doing something wrong, it was getting 12V to the solenoid with the key on, but the solenoid would never click or do anything, if I applied 12V directly to it or not made no difference, and when I took it out the little pin was all the way into the housing of the solenoid. Not sure if this could be a problem?

Anyway I'm sort of at a loss, I'm not sure where to go from here, and I'm pretty frustrated with the thing because now I'm wondering if it is a IP problem or if the motor has low compression.

Any ideas or suggestions greatly appreciated.

[ellis93]

Wonder if the vane pump inside the IP is getting weak on you,could cause this and has been mentioned to me before. The timing in side the IP is supposed to be controlled by the case pressures which is created by the vane pump

[PToombs]

Sounds like an air leak to me. It was bad and got worse. Take an air hose and a rag and put it in the filler and put some pressure on it. Check underneath for wet spots on the lines and such. If you haven't looked under there, look 1st, and clean any wet spots with brake cleaner. If you have a bad spot it will show.
I just had a problem with my 2nd gen after I replaced all the fuel lines, I aired it up, and found the leak on a connection. Saved me from pulling the tank and checking the module which was my 1st thought.

[booneylander]

Haven't pressure tested yet but I know there was fuel coming down from the top of the tank where the fuel lines come in. So I might be pulling air from there?

It would be easy for me to run a line from the inlet of my electric lift pump into a jerry can of diesel to see if that works. Will try that out tomorrow. Want to eliminate as much of the easy stuff as I can first.

Thanks! Will keep everyone posted!

[cougar]

Tell us more about the truck. There are differences between the 89 to 91.5 and 91.5 to 93.
If this truck sat for a long time, you could have things growing in the fuel tank clogging up the fuel system. Pull the filter and dump the contents into a clean, white container. The fuel should be clear and clean.
A solid click on the FSS does not guarantee the plunger is opening all the way. Remove the FSS and remove the plunger. See if that makes any difference.

[Tacoclaw]

Fuel above the tank is probably the steel lines in that area rusting through, or the rubber lines rotting. Either way, it's a problem and would definitely be a prime spot for an air leak, which will cause all sorts of problems like your describing.

[booneylander]

Truck is a 91 non-intercooled, reg cab, 2WD, DRW. Haven't been home yet to try lifting fuel from a jerry can instead of the tank so I will give that a try first, if that fails I will remove the FSS and take the plunger out.

When I bought the truck it had a newish 5th wheel setup in the bed and the guy had horse trailers so it had been pulling those, don't think it sat long. When I put the electric lift pump on, I put on a new fuel filter, dumped the fuel out of the old filter into a container and it looked mint.

Thanks for the help guys! Will keep you posted on results!

[booneylander]

Just to update this. I ended up bleeding everything and pulling fuel from a jerry can and it ran. Since then I've taken the truck apart and have been "restoring" it (for lack of a better term). One of the fuel lines had been rubbing on the frame and was worn through, letting air into the system.

[Tacoclaw]

Glad to hear it, man. Not a bad truck, just had a bad life prior. You treat it right and you'll find the reliability in it.