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Discussion Starter · #1 ·
Wheel Sky Tire Car Vehicle


Hello everyone! This is my second generation Pajero, (they call it Montero here). Originally came with a 4G54 Mitsubishi Astron gasoline motor (2600 CC).

Sadly, gas is getting really expensive where we live and it’s not the most economical. Plus the motor has nearly 400k kilometers on it! Diesel is still really cheap here! Thinking of retrofitting an Isuzu 4JB1-T diesel motor (2800 CC).

My biggest doubt…. Will it still have enough power? Comparing the specs, it looks like it should, though I'm not an expert.

Any other recommendation / things to keep in mind?

Thanks in advance for your opinions!
 

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They came with either the 4D56 or the 4M40 depending on generation. Those engines obviously fit perfectly. Indirect injection isn't my preference but the fitment is going to overrule almost everything else.
I haven't heard of anyone fitting an Isuzu 4J series to one.

Hyundai and I think Mazda took the mitsi 4D56 engines and developed them further. So they might be a source for you too. I don't know what you'll have available.
 

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I had a 4m40 diesel in the same pajero/montero. 4m40 is 123 hp and 217 tqs. Mine was automatic trans. I lifted it 2 inches and put 33s on it. Wasn't a bad truck but it was quite under powered for the mountainous terrain I live in. I live on the coast and the near by mountains go from seal lvl up to 5-6 thousand feet. Loaded with camping gear it wasn't the fastest thing out there, 70 km/hr. That's after I put a one size up turbo and turned the fuel up.
Where it was awesome was off road. Plenty of torque and crawled around the bush amazing, sipped the fuel.
But on the hwy it was working too hard and was 23-25 imperial mpgs.
Overall I did like it, but It couldn't tow my quad and interior space was getting too small for my family. My advice would be to get a bigger diesel engine or a gas engine around 170-200 hp and ud get the same mileage and have more power.
 

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Discussion Starter · #4 ·
Hey guys! So I did the swap! It's been a long two months. :) But we're there now. Here is a pic of the new Isuzu 4JBT-1 in our 2nd generation Pajero.

The mechanic did a great job adapting it. There was lots to do, and lots other things that needed to be fixed too that we discovered along the way!

Couple questions for you diesel experts. This is my first diesel. We adapted an intercooler to this, as you can see in the picture. Originally there was a metal pipe running from the turbo straight to the air intake on the other side. But we removed that pipe, modified the intake, and now have the air passing thru the intercooler.

We've put a 1000 kilometers on it so far. Running pretty good, though the idle can be a bit unstable. We changed a few parts in the pump that were supposed to make it run smoother. It runs a little better, though I'm noticing something weird.

Whenever the engine returns to idle it always seems to go too low and shake violently for a quick second before stabilizing. Any ideas what it could be?

We had to make a custom air filter box. My old man thinks it's too small. You can see it there partially on the picture.

Appreciate any opinions! :)


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Nice job. The intake hose looks a bit small and smooth is better than bumpy. Going up a size tends to help with turbo spool and top-end power.

For your idle problem, check the fuel return isn't stirring up bubbles in the fuel tank.
 
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