After some testing tonight, I've got the tach working. There are 2 wires coming from the tach sender on the injection pump, one black and one black/red. I've tried connecting both of them to the tach signal input with no success, and was left wondering what they both were for.

After digging through another non-USA Isuzu service manual, I found a wiring diagram showing the tach sender. In it, there are 2 wires listed (black/red and black/p, which could mean purple?).

The bk/p wire was run to a ground while the bk/r wire ran to the EGR/QOS (glow) controller, so I figured that had to be the signal line. I reconnected the bk/r line to the tach as signal and grounded the black wire and just like magic, I had a working tach.

Not sure why one would have to be grounded, and why the sender isn't just grounded to the pump body. Maybe the pump isn't grounded? Anyway, it works perfectly. I am using a C223 (1986 diesel Trooper) tach, which has a different redline and (according to Jerry Lemond) is designed to work with the signal from the diesel sender - a gas tach is not supposed to work, I have not confirmed this though.

That's great.
You got the gasser tach to work on the diesel injector pump signal. I've had to add a capacitor to the signal lead to match up odd equipment. Jerry or someone else might verify this, I think the signal coming from the sender in the IP is two wires, because it comes from a coil and magnetic armature. The symbol for a coil is similar to that of a lamp. You can ground one side but it isn't needed. The potential is between the two wires.
Since I am more familiar with German cars I don't know with any confidence, but the letter "p" might be Pink, whereas, the letter "v" is for violet or purple.
So you must be driving the Trooper around the garage if not around the block by now. How's it feel? I remember the first time I backed my Merchevy out of the garage it had been in for six months. Exciting and freaky at the same time. Listening to every tick and creak...
Good luck <img src="/forums/images/graemlins/cheers.gif" alt="" />
Brian Rodgers

Actually, I am using the diesel tach. I do plan on hooking the gas tach up just to see whether it works, but I've been told it will not.

I guess that connecting one side of the sender to chassis ground and the other to the tach input signal creates a potential between the signal line and ground (as the tach is also grounded).

It's actually not a nerve-wracking experience to drive the Trooper around (around the driveway, that is, until I get the fuel tank back in) as I didn't have to fabricate any mounts etc - I am confident in using all Isuzu pieces, which was one of the project goals. Driving my Acura after the rebuilt (by me) engine and transmission were first installed was much more worrisome.

Just to confirm, the gas tach will not work with the diesel engine (plug-any-play, at least).

This is a really great thread. I've been toying with the idea of putting a small diesel engine in an S10 cuz I'm sure not gonna pay the crazy thousands that VW pickups go for on ebay.
I'd be very interested in your MPG numbers, according to my calculations I could get 40-50 MPG with the right diesel engine in my S-10 and tall enough gears to keep the engine around the torque peak at highway speeds.
I ran across the guy who put that Cummins in his Jeep while I was researching that Cummins B3.3 after I saw it in Diesel Progress. I was a little dishartend by his 30 MPG but after some more research I found that a Jeep's Frontal Area*Drag Coefficient is over 16 vs an S-10 at below 11. I think that fact alone shows that a 40 mpg S-10 is a real possibility.

The only problem is going to be height. Does anyone know what the dimensions of the old C223 Isuzu diesels were? What about power, torque and BSFC data?

Yeah Acy76 is doing a crack job with his Trooper. He is using the Euro Isuzu diesel engine at least I haven't heard of the 4JB1-T being used here in trucks. That said I want one too. This is the better engine by leaps and bounds than the C223-T which I have in my Trooper. Recently I have been offered a 4X4 loader for dirt cheap because it has a blown engine, was propane, I have an itchy feeling that is telling me this would be the place to do an engine conversion. I hear the Isuzu 4JB1-T was used in industrial applications like small loaders, fork lifts, ect. I don't even know what make the loader is. Maybe International. I need to do more research on this project, might be a good way to spend a Winter. Anyway, I have three Isuzu in the yard at the moment. One is a gasser Pup with a blown engine, (toast) waiting for an inspiration, or two. The other two are Troopers. One is mine, the other I am working on for a fellow 4x4wire member.
My Trooper has the turbo C223-T and the other is the normally aspirated C223. Both engines look to be of a normal height. I have heard the C223 was offered in the Pup which is one of my early hopes to do a swap and conversion in ours. If our Pup was four wheel drive I would do it, alas it is two wheel drive, but you are right about the drag and fuel mileage on the smaller and lower two wheel drives; More better for sure. I am hung up on four wheel drive vehicles. Considering where we live (NE New Mexico 7000') and it looks like we are in for a kick arse Winter, we need all the wheels pulling for us. So yeah the C223 whether turbo or not is a low profile engine. I will head out to the sawmill where the loader is and get some pictures and post them here. I may even begin to fit in with the rock crawler crazies when they see the tires and suspension on this beast.
Sincerely,
Brian Rodgers
<img src="/forums/images/graemlins/baby.gif" alt="" />

As far as fuel economy is concerned, I am anticipating around 30 MPG based on what I've heard from other drivers. No hard numbers yet, as it's still under construction. Quite an improvement over the 20 MPG the gasser gets.

As far as pickup engine conversions are concerned:

Take a look at eBay (search "isuzu diesel") - currently, there is a P'up advertised that has been converted to diesel using a small 4-cyl. that may be the OHC four Jerry was referring to in an earlier post (possibly in this thread). It is certainly not the 4JB1 or C223.

I think the engine code is 4Fxx but I am not certain. At any rate, it is supposed to share a bellhousing with the 2.6 gas engine and should drop right in to the pickup chassis. Jerry is the expert source here - someone could contact him to confirm. This could be the P'up version of the Trooper 4JB1-T swap...

As an aside, I do not recommend buying this engine or that vehicle from that particular eBay seller, as I have spoken with him and his prices are nearly double what my supplier charges - and, if I recall correctly, his price didn't include the transmission!

Hello all

I am asking this information on behalf of a friend. Does anyone know the original IHI turbo model which came with the 4JB1T? This is a JDM engine. The turbo has blown and we are looking for a suitable turbo to fit into it. Kindly let me know what fits or I can do a cross reference from stock. Thanks.

I've added a couple of new posts to the blog (link is in the signature).

Noteworthy is the fact that I've finally got my hood scoop! Check the photos on the site...

A short update note (in case everyone thought I'd given up on this thing) -- I've been quite busy lately with things non-diesel, so progress has been slow. I've decided to apply to graduate school, so the next month or so will be dedicated mainly to that effort.

I've started cutting the old hood up to repair rust at the front edge. After that, I will duplicate the support structure that the factory intercooled hood has and cut the hole for the scoop. So, the hood is the next big item on the list.

I've also got to get all the rust out of the cooling system and plumb the fuel lines.

I spent the day today at a garage (used to work there, know the owner so I get free shop time now and then) mounting 5 new tires for the diesel Troop. Actually, 2 tires I already had which have like-new tread and $40 worth of Craigslist tires, which are also basically brand new. I'd been waiting patiently for a good deal on tires and it paid off. I also managed to grab 3 BFG tires, one of which is my spare, so if anyone local wants 2 used BFG truck tires in great shape for a great price, let me know.

And that's the news for now.