Isuzu 4BD1-T swap into a '92

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

We have all been there. I figure il be there two more times with mine before complete. I did finally get my flex plate back and making slow progress.

Keep pushing forward

Thanks man! Looking forward to seeing yours up and going! Too late to turn back now anyhow
 
Trans

I am going to Vegas tomorrow to pick up a used trans. It has approx. 15k on a complete rebuild, for $250. I have to pull it. Motor went south for this fella, think the truck has 220k on it, its a '91. What are some things to check out on the trans? He says he has paperwork somewhere, but would have to dig to find it. The owner was once located in flagstaff, I am guessing the trans was rebuilt there, anybody know of a shop in flag that would rebuild these, and quality?

On other notes, exhaust is on, went to the exhaust shop today, but the fellas kinda spaced out on the interface from the downpipe to the rest of the system. It rubbed the front tire at partial turn. So we talked about it, (he knew it wasn't gonna fly), it's gonna be tucked up there nice and purty. The rest looks awesome!, 2.5" all the way back, and the muffler is tucked up above the bottom of the frame rails, and the exit sits just above the bottom of the 4x4labs bumper, very nice work to fit it in with no rubbing. They are also bending some tubing for the lower radiator hose to make the two connections more straight on. I'll get some pics up.

Also, is it possible to r&r the trans without pulling the motor? At this point pulling the motor takes an hour or less. But now I gotta disconnect a bunch o' more stuff, just wondering what makes the most sense. What say ye?

And, my exhaust guys are also radiator guys, and Jeremy, you were spot on about the plastic ties tearing up radiators(not that I doubted you!). So when the trans is getting pulled, I am going to get in there and make a mount for the trans coolers, and get rid of the plastic.

So, I have a couple solid days of work ahead of me, not including getting the motor to run correctly, but I think I have a handle on that.
 
Sounds great! 15k on a rebuild sounds awesome for $250. I would check the fluid make sure its not burnt. Then make sure he has that receipt and it matches the milage on the truck you are taking it out of. As for taking the trans out I found it easy to pull the engine and trans as a unit. The wiring for the transmission is connected to main wire harness I think, so depending on the way you wired it its easy to pull the two out as a unit. I always find it hard to balance the transmission on the jack and not damage something.

The exhaust sounds great, I'm going to try and make 3" fit, see how that works :S.

What are the plans for the running issues?
 
running

I should get the truck back from the exhaust shop today, and I might have a few minutes to play with the running issue.

First thing I am gonna do is put on some clear lines like you suggested, and see what that gets me. Then I will get in to the tank and run a hose on the return farther from the pickup. I am also going to check oil flow from the filter to the injection pump. The running seems to have gotten progressively worse, but I have also been fiddling with the fueling screw. I got some diesel purge and will run that through the pump also.

Looks like saturday I'll be pulling the engine and trans. I am kinda looking forward to it......
 
Update

I got a chance to do a little more trouble shooting, and I don't have a reason for the poor running at a higher rpm range. It must be sucking air or something right in a narrow range. Floor it and it goes away, or back off a little and it goes away. Hmmmm.......I'll be putting the new transmission in next week or so.

I ran new fuel line from the tank to the water/fuel separator, that seemed to help a little, I even put an auxillary pump to help push it, but didn't make a difference. But I have been enjoying driving it, even if the top speed is 35mph. That feels good!

So I might take it in to a diesel shop and see what they can tell me, I've run out of things to try, except maybe an inline air/fuel separator. But I have been tidying up loose ends with the wiring and little oil leaks. I got the pyrometer and boost gauge up and functional. I played with different springs on the turbo actuator, very interesting to watch the difference in boost vs. egts. Lower boost = higher egt's. The TDO4HL-19t pushes boost right off the line. It gets up and goes pretty good, just don't have the fuel to keep up with it yet. Boost is about 12-15 psi, planning on getting a stiffer spring to crank it up a little when the fueling issue is resolved. EGT's stay below 1100 even at max boost/loading
12277140563_0d33c88465_z.jpg

One little pic, I used two of the autometer gauge pods for the 80 series, had to cut them both down so they fit in the space.
 
Well we know it was fine pre swap so it must have been something done wile swapping. I too would check that strainer on the pump. Make sure all the connections are tight and no air can get in. Is it still puffing out white smoke when it does it? Usually when there is a fuel restriction the engine will just feel down on power not miss or puff white smoke.

With the inline pump a leak would usually show up because its now under pressure not vacuum.

Sounds like that turbo is working well, cant wait to see how it first hand. As boost goes up the EGT's will drop if fuel is not adjusted. Sounds like you got lots of room to go. I got a 15 and 25psi spring for mine.
 
Where is the strainer on the injection pump? When it starts missing it pours out the white smoke. I am not running the inline electric pump right now, it was just for troubleshooting. I did find one loose banjo fitting on the lift pump, everything else was snug.

I am running the red 25 psi spring, it translates to 12 psi at the intake manifold where I mounted the sender. I am also just barely getting 1000 deg. egts. (I just watched a video of the gauges, more accurate info).

I will check a few more things this week. but even with the line dipped directly in the tank without going through any filters it did it. Scratching my head, probably something simple, just need a fresh set of eyes.
 
Something I just thought of, when I was bleeding off the injection pump with the little push pump on it there was fuel coming out of that when it was open when I had the inline electric pump going, hmmm, maybe gotta check that out.
 
Sounds like the exact issue i was having with my engine on the stand. I went through everything trying to fix it. I thought I had narrowed it down to air getting in. Each time it did it it was clouds of white eye watering smoke (diesel vapor). If it does it again in the trick when I get it going I will pull the pump and get it rebuilt. Its the only thing left on mine.

The boost sounds like you do not have enough preload on the gate. A 25psi spring should be very close to that. What is your pre intercooler psi? If its 15-18psi as well you need to tighten up the gate adjustment to get more preload on it.

I hope you can get that miss sorted out I have fears I will have issue with it again and need to pull it.
 
I don't have a gauge pre-intercooler, but I have another clue on the running problem.

Today I disconnected the turbo from the air filter and the problem almost went away completely! It would still blow a little smoke, but the miss is hardly noticeable now. I am also getting a grey to black smoke when I get on it (just a smidge). I noticed that the silicone that I had used for the intake routing was collapsing under acceleration, so I disconnected it and voila! The difference was instant.

What is this telling me? Besides that I might need to re-think my intake set-up completely.
 
Very interesting! How much did boost go up when you tested it? Sounds like its getting choked right out when it collapses.

Those couplers should be able to handle the vacuum the turbo makes. It sounds like you have a plugged up air filter or something else....rag in the air box?
 
Boost went up to 15 psi. Couplers aren't the issue, the air box and snorkel appear to be too restrictive for this turbo. I put on a conical filter before the turbo and it runs much better, but LOUD. It still has a little miss/hesitation at just the right throttle/load/speed combo, smoke is associated with this, just not like it was doing. It is much better overall. I tried using the hard pipe set-up from toyota filter box (the first version), it ran just as poorly as the flexible silicone. I need to kick up the idle a little, it is a little rough when in gear at a stand still.

So I guess I need to start planning for an airbox on the drivers side? JDM snorkel? or something?
 
Boost went up to 15 psi. Couplers aren't the issue, the air box and snorkel appear to be too restrictive for this turbo. I put on a conical filter before the turbo and it runs much better, but LOUD. It still has a little miss/hesitation at just the right throttle/load/speed combo, smoke is associated with this, just not like it was doing. It is much better overall. I tried using the hard pipe set-up from toyota filter box (the first version), it ran just as poorly as the flexible silicone. I need to kick up the idle a little, it is a little rough when in gear at a stand still.

So I guess I need to start planning for an airbox on the drivers side? JDM snorkel? or something?

Odd those air boxes are working fine on 1HD-t's running far more boost and more CFM. What snorkle do you have? Somthing sounds off or plugged. Not sure if you want to try this but eliminate one component at a time, you already have it narrowed down to the air box/snorkle. Try narrowing it down further, take the air filter out first for a short test, then if that was not it try the snorkle. How large is the opening from the old AFM filter top/adapter?

I really want to retain the stock filter setup and was actually looking at getting a snorkle for mine too.

...via IH8MUD app
 
The airbox you have looks a lot more restrictive than the factory HDJ81 box. It certainly isn't the same one.
 
The airbox you have looks a lot more restrictive than the factory HDJ81 box. It certainly isn't the same one.

The lower part is the same its the upper cap and flange that is diffrent on his. It does look quite restrictive. My 1fz cap has a 3.5" opening comparing to the other 3 I have here its by far the largest. The HJ60 one is vary restrictive looking and its handling 18psi on a 4L diesel at 4000RPM on my brothers truck.

Like I said i think something it going on somewhere in there.

...via IH8MUD app
 
I'm running an HJ60 box on my FJ60 and the larger FZJ80 box on the FJ40 and they are both more than enough air flow for this engine. I'm running 22 to 24 psi of boost on both of them at max and neither one chokes out. The one with the HJ60 box has a snorkle on it as well.

Just some real world experience with this engine, so I don't think it is the air box.

Don
 
Interesting, I wonder if my turbo choice has something to do with a potential air flow issue? (TD04HL-19T)

Don, what turbo are you running?
 
I'm running a Garrett T3 with a .48 AR on one and Holset HX30 on the other. :)

Don't know if this helps as I'm no turbo expert at all. I know just enough to be dangerous in that area.

Don
 
It's been a while, time for an update.

I got the trans swapped, it hits all the gears, just need to adjust the pull radius on the tv cable so it mimicks the toyota range more accurately. At the present, the isuzu throttle linkage pulls too much cable making upshifts not happen like they should, although you can trick it by driving it like a manual with the throttle.

I also adjusted the valves and it seems to have cured my running problem, Yay! It is still a little hard to get started in the morning, but after it warms up it runs pretty nice.

Now that it's running mostly correctly, and shifting, I have noticed it really piles on the boost and egts. So I have some tweeking to do, I can easily hit 1200 deg on a incline.

So far so good, and I am going to hook the toyota inake system back up and see what happens. I had a diesel shop do some tests to help diagnose the running problem. One thing they told me was the downpipe was very restrictive, which I believe would also help create excessively high egts, so I am going to try and get a wider/larger pipe on there to help free up the restriction(they did pressure test). But everything else looked good to them, they were impressed at how much air the turbo flowed, from the bottom all the way to the top. So far I am happy, getting happier with every hour that I can spend on it, seeing some progress!
 

Users who are viewing this thread

Back
Top Bottom