3.4 swap into 91 Trooper

[greener]

I'm in San Francisco. Can I just go to a GM dealer and ask them to order me the engine?

[Canyonero]

I think you probably could. Might dodge freight that way. Are you going to do it yourself or take it to a shop?

[greener]

I'm doing it myself

I've scoured the forums and put together a decent project schedule, now I just parked the Troop where its going to sit during the project, and its time to order the engine, and get the ball rolling on this long overdue endeavor.

I'll try to keep a bit of a journal and pictures of the progress.

[Canyonero]

Is it still clacking along with noisy lifters? How many miles?

[greener]

Yep, its been sitting this whole time, so its still the same clackity old '91 with 135k on it. The rest of the truck is in great shape and I like the beast, so I'm happy to be ready to get the new engine in finally.

[Canyonero]

135k? That's not much. Mine had 163k on it when I took it apart, still running fine. I'm actually going to be re-using my old engine in a couple weeks (hopefully) to replace the hosed engine in my friend's Trooper. His is knocking because he got loads of coolant in the oil from a manifold gasket failure at somewhere around 200k.

I wonder if we should start a new thread for your swap. I totally hijacked this thread from another guy. It could become the ultimate Trooper swapping thread...

[greener]

Yeah I could definitely get the current engine back into shape, but I never liked it's gutless performance. I figure why not upgrade. So, anyone want to buy a 2.8 core?
And yeah I'd make a new thread when I started the actual work, in fact we should continue this convo in PM's too I suppose.

[Canyonero]

So, anyone want to buy a 2.8 core?

Buy? Not likely.

[Ed_Mc.]

Well, you could always rebuild with an overbore and "stroker" 3.1 crank. Add an HT 3.4 crate motor camshaft and 1.6:1 roller-tipped rocker arms.

It would at least get out of its own way!

[greener]

This simple swap will still be the most major work I've done myself. Cracking the engine open for real to do a stroker would have to be a future project, and I'd need a better location, ie somewhere indoors.

I did the clutch on this truck a few years ago, and that was the most I'd done up to that point, and it let me feel good about doing the engine this time.

So what is the best thing to do with my old 2.8 core engine? Give it to a yard?
Give it to a forum member? I don't expect any money for it, I'll just need it to be gone.

[Canyonero]

Back at it again. I think my flywheel is loose and getting looser. I stopped driving it. Took my original flywheel to the machine shop to get re-surfaced and ordered a centerforce dual-friction clutch.

[Canyonero]

Concerning the last post, it was bearings in the tranny, and my clutch was ruined.

New centerforce dual-friction clutch and new (used) tranny installed. All better.

Anyway... now for this:

I'm wiring my emissions stuff back in. EGR, evap canister, VSS. I pulled all the wires from my old harness to install in the FIS harness.

According to the Fuel Injection Specialties docs, their harness would normally only have the purple VSS lead (high). No yellow (low). My Trooper only has one yellow lead. 4000 pulses-per-mile sticks in my head, but I'm not sure if that's the correct application. Trying to find my Trooper manual...

Here is a diagram, any ideas which I should plug that into?:

[Canyonero]

IT RUNS! MY ISUZU TROOPER WITH A 3.4L SFI RUNS!

Gonna put in some hard work tonight and tomorrow, and maybe I'll be able to drive it this weekend! I'm pretty freaking thrilled. This rig has been down for over a year. Nice to hear it run again.

Wow, it seems like it's been more than a year. I'm still working bugs out. About to take it down again for a major reworking. Going to install the Crane H-260-2 cam I've been sitting on forever (also lifters, chain, springs, etc), swap over to the right side Trooper accessory brackets so I can get my AIR pump back and clear the battery in the original location, swap to the 3.1L intake to get better flow and better clearance, and the big one: replace ALL that expensive wiring I bought. Rewiring for a 1227727 ECU.

For anyone considering a swap like this, DO NOT USE THE 94-95 ECU. THEY ARE A BLACK BOX, TROUBLESHOOTING IS VERY DIFFICULT!

[Canyonero]

New harness is loomed. I feel much better about doing this one myself: