Thank You so much Jerry.
I think I may be getting this.
Man, I hope you know how much I appreciate this tutorial. Thank you. I did a few more tests yesterday. I did figure out that I was on the wrong wires for testing the fuel cutoff solenoid. Whoops. Yes, I saw the voltage at the two wires fluctuate while turning the engine over. I then got my nose down in there better and discovered the single (blk/yel) wire like it shows on the schematic on the back of the injector. I also read 12v when turning the key on. Seeing the power to the solenoid gave me more confidence that my problem was elsewhere, so I moved on. The symptoms on this engine are not that it just idles after the key is off, but this engine seems like it is running ultra rich and revving way up there.
Yes, it is getting a very good fuel/air source from somewhere. I can not rule out that I have installed hoses in the wrong place(s.) Like I said, the jerk mechanic before me left all the lines off of the fuel injection system. I do feel confident that they are correct, if only because they all have the proper bends and look like this is where they go. Thank goodness rubber has memory.
Onward through the fog. I needed a way to test the turbo seal and if nothing else rule it out as the source of fuel. I found this method and I think it proved something. I pulled all CCV tubes from the junction between the air cleaner and the turbo inlet, inspected everything as I pulled each. I made proper plugs for the two pipes on the top of the valve cover. Then I got a bright idea to pull the rubber elbow between the turbo and the intake manifold. With this elbow off, the turbo is still lubricated and spinning, yet no air is drawn through it to the engine. As an added bonus, I found a PVC pipe cap which fit snugly over the end of the elbow to facilitate suffocating the engine if necessary.
With a tinge of trepidation, I was ready to go. I primed the fuel system, installed a new battery, did a double heat with the glow plugs, and turned the engine over. I may need to check the glow plugs because the engine did not fire for several spins. Not even a little sputter, and no smoke from the exhaust. I double checked that fuel was at the injector pump, yes. I tried the starter with a dab of gas pedal, which by the way feels like it does not travel very far. In the back of my mind I wonder if the linkage is installed correctly. It's just a cable which goes directly to the IP. I put the cruise control cable on the same place as the accelerator cable. The throttle arm is against an idle stop, but something seems weird there. I have gone over it again and again since the engine's symptom is over-revving, I can't see what could be wrong, but again this was a basket case when I got it.
Anyway, the engine did begin to fire. I gingerly used the pedal as I didn't want to hear my little baby take off like a rocket again. I would let it sputter at low RPM for ten seconds and shut off the key, just to be sure it would shut off, it did and I felt better by the minute. How the engine sounded? Oscillating, with the rap coming and going with engine speed, maybe? Not sure about the sync there, but the rap wasn't always there anyway. To me, who knows very little about diesel but a great deal about gas engines, this engine was running very rich. In electroics we call it motor- boating. Heck it may be that a little oil remains in the cylinders until the engine gets up to the proper operating temperature. Like my dad says, I don't understand everything I know about this.
The truth is, I never heard a diesel engine sound like this Isuzu sounds. It sounds more like a gasser than any diesel I ever heard. This is one of the reasons I think it is running rich. Either that or this is one tight engine. I didn't let it run very long, I'm afraid to let it runaway again. God only knows what kind of engine wear it is receiving at that RPM. I want this engine to work, I don't want it to blow. I know, I know, you want to know if the freakin' thing shut off with the key or what? A little bit of both, sorry. Once it warmed up (a minute or two) it started going faster like 2000 RPM, I turned off the key. It did stay running, but this time it shut off before I could get out to the engine compartment.
What does this episode tell me? It tells me the turbo indeed may have been part of the problem. It will be worth further testing of the turbo. I will look at the oil blockage scenario, thanks for the tips Jerry.
I feel much better with 2000 RPMs and can work with this. I don't feel like the engine is going to self destruct in my face now. So this in my book, is progress. I will try again.
Brian Rodgers <img src="/forums/images/graemlins/kewl.gif" alt="" />
