Realized I hadn't updated the thread in a while. Most of my work has been getting the fuel system finished up.

I've got the tank back in with the modified pickup tube and been working on a mounting bracket for the fuel filter/water separator/primer pump assembly. I've got the assembly and bracket from an 86 diesel Trooper, and while the 1988 chassis has provisions to mount it in the stock location (passenger fender, near battery tray), I need to relocate it because my SVO tank is going on that fender and the intercooler interferes with the filter anyway.

I was able to make a bracket out of angle iron which attaches to the driver's side fender in 3 places, requiring only 2 new holes to be drilled in the fender. It mounts in the hollow just forward of the brake master cylinder, which is a great space for it. I also added another small bracket to the top of it to mount the glow plug relays.

It's great fun working in my ultra-cheap metal fabrication shop. For anyone interested, I've outfitted myself at Harbor Freight with a metal cutting bandsaw, drill press, bench vise, assorted clamps and a grinding wheel. Add to that a Lincoln SP-100 welder w/ gas kit and it's really a fantastic budget setup.

Photos are up on the blog site.

I'd like to make a request, if I may:

I thought it would be cool, as a finishing touch, to have a factory 'TURBO/D' decal on the rear door of my Trooper. Does anyone know where I can obtain one? Or, failing that, would anyone be willing to send me a high-quality, high-resolution digital photo of theirs? I can get one made from the photo if need be.

This will give me some incentive to patch the bottom of my rear door... the only really rusty spot on the truck.

As usual, any information is much appreciated.

Keep an eye out on this seller. He had some turbo decals for sale a couple of weeks ago. http://motors.search.ebay.com/_W0QQfsooZ2QQfsopZ2QQsassZ73ssnova01ks

First off, a public thanks to Jerry for the decals. An unexpected surprise in the mail... if anyone needs parts, be sure to support Jerry! I'd still like a nice photo of a 'turbo/d' rear door decal if anyone could supply one.

I've added a few posts to the blog site (www.dieseltrooper.blogspot.com) with some photos and updates.

PLEASE READ THE NEXT PART!

Now for a problem: I'm ready to start this thing finally, but I can't figure out where the fuel cutoff solenoid is located and/or how to wire it.

My assumptions: that the fuel solenoid is supplied a constant +12V during start or run to hold it open to supply fuel to the pump. This is how it appears to operate after examining the wiring diagrams for the 86 diesel Trooper and the 2000 3.1 diesel Trooper (I haven't got one for the 4JB1-T).

In this photo (also can be seen on the blog) I've noted the two things I thought might be the cutoff solenoid:

The box marked '1' is a cylinder with one wire going to it (with a boot over it; wire & boot removed for photo). There are 3 fuel lines connected to the base of it, one of which is visible. All 3 appear to be return lines - the visible line is the main return to the tank.

The '2' shows the very edge of another booted, one-wire connection underneath the first cylinder. It is located on the top of the part of the pump where the lines come out and go to the injectors.

The wires going to both of these things have continuity with ground. I tested them with a continuity tester and with a test light, and both are grounded. Supplying power to either one results in a direct short. Nothing else on the pump looks like it could be the cutoff solenoid. There is a 2-wire booted connector on the side of the pump, near the engine block, but 1) it has 2 wires and 2) I think it's the tach sensor after looking at a manual (could be wrong).

So, what am I missing? Do either of these look like the solenoid? Should it have continuity with ground? Is it a bad solenoid perhaps? If they're not the solenoid, what are they?

Any and all ideas welcomed.

THE SOLONOID THAT SSTICKS STRAIGHT UP UNDER THE FUEL LINES IS IN THE MAIN PMP HEAD AND IS THE FUEL CUT SOLONOID,(N02) 12 VOLT AT ALL TIMES WHEN IGN IS ON, THE ONE DOWN ON THE SIDE OF THE PMP IS THE TACH SENDING UNIT , I AM GOING TO HAVE TO MAKE A GUESS AT THE OTHER ONE STICKING TRAIGHT BACK , IN THAT IT LOOKS LIKE A VENT SOLONOID WHICH WOULD EXP, WHY THE LINES ARE RETURNING BACK TO THE TANK , THE GAS ENG THIS WOULD BE A VACC, OPERATED VLV BU THE DSL IT WOULD HAVE TO BE ELECTRIC, TO CONTROL TANK VAPORS AND RETURN LINE FUEL AT THE SAME TIME THIS IS JUST A WAG ON THAT ONE JERRY

Jerry, the #2 candidate in the photo is what I am leaning toward as well - I took another look through the diesel engine manual and also got some information from a New Zealand forum.

The other part, which you feel may be a vent valve, I believe may be a sensor. Since the terminal is grounded, it can't be any sort of actuator (unless it is broken and shorted to ground). I am thinking it's more like the oil pressure switch on the engine and makes/breaks a ground path depending on conditions. I am not sure what it might be a sensor for - loss of fuel pressure?

At any rate, I am still puzzled by the fact that the suspected cut solenoid has continuity with ground. Unless I am testing the wrong wire or making some other silly mistake, applying power to it will result in another short. I am going to remove the boot and test the terminal directly next, which should be interesting since it's hard to get at.

Thanks for the insight.

More later...

Check the resistance. If it has continuity but also enough resistance to not blow anything (a 200mA solenoid would have 60 ohms resistance min) then you've probably got the right wire.

acy76--

The solenoid in the head assembly (your item # 2) is certainly the fuel cut solenoid and the other is most probably (since I can see it from only one angle) a timing advance solenoid.

Both of these devices have windings which will draw 1 to 2 amps from the 12v ignition system, giving them a resistance in the range of 6 to 12 ohms. This small resistance may make the device look like it is shorted to ground. But if you check it with an ohmmeter on a x1 range you will be able to measure its resistance and see that it is not shorted. Also, if you apply 12v to one of these you should get a small spark and hear the solenoid click.


The timing advance solenoid works by changing an orifice in the fuel return line resulting in a change of pump housing pressure which in turn will change the injection advance.

Paul

Hmm.. I do recall saying something earlier about a silly mistake - never thought to check resistance. I forgot my basic electrical theory I guess. I was led down the wrong path after first connecting the power wire to a grounded sensor on the thermostat housing (tried to find the wire for the solenoid by checking continuity between the harness and the terminal - first ground wire I came across made the box beep, so I went with it. Oops.) and then becoming obsessed with short circuits afterwards.

Any idea as to what the backpressure solenoid might do? As in, what system (EGR, quick warm up, etc.) it is part of? Hopefully it's not essential to running the engine, as I have no controller for it at all.

Thanks for all the input, you guys really helped (as usual).

Well, first thing's first, I got it started tonight. Seems to run just fine, although I have no exhaust on it and couldn't hear any engine noises if it were making any.. only problem is a fuel leak, which I'll get to in a minute.

The previously mentioned solenoid (#2 in the photo) was indeed the fuel cut unit. The other solenoid is, as Paul pointed out, a timing advance device which is used in conjunction with the QOS II glow controller. I haven't got that box, so I guess I could hook it up to a switch. Supposed to help it run in the cold a bit better.

Now: I am wondering if I blew some seals in my injection pump. There is a decent leak coming from the underside of it. I haven't tried to get a real good look yet, but it doesn't seem to be the lines.

I couldn't get the thing started for the life of me. The primer pump would not draw any fuel from the lines into the filters (is this normal or is my hand pump shot?), so I hooked the old gasser in-tank fuel pump up and used it to send some fuel into the filters from a jar of diesel. I accidentally pressurized the system, though, because as I removed the hose from the electric pump fuel sprayed everywhere. Did this pressurization blow seals in the IP? Would/could it have done any other damage (ruined my new fuel filter, for instance)?

It runs like a top now, save for the leak...

Ideas welcomed, as always.