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1990 Izusu Trooper 5MT - First Izusu

12K views 71 replies 10 participants last post by  6079smithw 
#1 ·
Hi!

I'm completely new to this forum, completely new to Isuzu and completely new to SUV's.

I come from a background of Mazda's. Specifically, rotaries and Miata's. I recently decided to sell my miatas and head in to the off-road scene. I initially started looking for XJ's and 4Runners but gave up after a few months of relentless searching in SoCal. There just didn't seem to be anything available in decent shape. I did a quick search of Isuzu's and practically bought the first thing that popped up. Boy did it pay off. I managed to find a 1990 Trooper with 123k mi. Paint's immaculate, interior's immaculate and everything works. All for an extremely reasonable price.

I'm not entirely sure what to do first. I was originally thinking rock sliders and fresh tires (it seems like 33" tires are the best bet). However, because of the "mint-ness" of the car, I'm a little reluctant to do anything to it at all. I know that eventually the modding-bug will creep up on me and I'll have to do something, though. As for right now, I'm dedicating myself to fixing the minor problems:

- Missing dome-light cover
- Temp gauge doesn't work (gunna check sending unit)
- Door handles might get wrinkle-paint
- Manual hub locks

That's it. There are literally no issues with this truck. I took a peek underneath and there seems to be a minor leak from the rear seal. The coolant looked a bit brown so a flush/alum. radiator/hose refresh might be in order. There isn't even rust on the underbelly. Not even surface rust. The steering is a tad loose so the tie-rods will probably go as well.

Oh and... I'm drunk as I'm writing this so it might be a bit all over the place.

Anyhow, here are some pics









 
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#2 ·
Nice find, and I would have bought that one too. I see, the v6 emblem on the fender so you have the 2.8. Very well liked here by many, and with parts as you need them, plentiful, you will like this as well. You didn't say if you got the 5 speed or the auto, so which one? As to the tie rods, yes that would be a good place to look for slop in the steering. If you do have loose tie rod ends, consider the mod to convert them to heavy duty one's. It's a fairly easy mod to do. And there is some adjustment in the steering box, but you don't want to start there. Oops, I saw the interior picture and you have the 5 speed. I need to look closer.

http://members.shaw.ca/isuzutrooper/isuzususpension.htm
Compliments of our Canadian member, Geoff, who is very familiar with all the v6's
 
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#3 ·
Thank you!

It is indeed the 2.8L. I've heard mixed reviews about them. They seem to be pretty bulletproof, however. And if I'm not mistaken, the run on a timing chain? I've thought about a 3.4L later on down the line. I understand they're not horribly difficult to swap.

It's a 5MT and I LOVE IT. The shifter's a bit sloppy but I'm guessing that's because I'm used to Miata shifters and not truck shifters. I might just leave it alone for now... unless someone can point me in the direction of a shifter rebuild kit?

I've taken a look at the heavy duty tie rods and I think that'll be my first move. Sloppy steering has always been a huge pet peeve of mine and it seems like every single used car in existence gets sold with loose, sloppy steering.
 
#4 ·
Nice score! GM V-6s had some issues on intake gaskets and (lesser issue) exhaust manifold bolts breaking. Shifter may be the bushing at the bottom of the shifter handle. Fairly easy fix and I believe available from our resident Isuzu guru and parts source user JLEMOND. Welcome to our family. Dennis
 
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#5 ·
I just spoke to the head of R&D at one of my client's shops and he said the 2.8L GM motors have a tendency to blow out head gaskets rather frequently. I've also read that on this forum. Is this really that big of a problem? What steps can I take as preventative maintenance?

And you guys have a user just for parts? Haha I was just going to head on over to RockAuto but I'll PM JLEMOND instead.
 
#6 ·
I never had a problem with head gaskets on the 2.8, the intake manifold might leak but mostly it is the O ring on the distributor and valve cover gaskets. Man that thing is clean. Good score. The 3.4 is a good upgrade but with the lower miles on the 2.8 I would not be in a hurry. Might not hurt to score one for a future upgrade, as they are not as plentiful as they once were. Upgrade the exhaust to a 2.25 dia and put a better flowing cat and muffler will show a power increase right away. Another simple one is to upgrade the intake to a "bored" one. Lots of info on that one on Geoffs site. As far as the swap goes it is not to bad with some simple skills. Mostly it is a drop in.
 
#7 ·
Ahh ok. That puts my worries at ease. And an intake manifold leak sounds pretty harmless.

Good point on the 3.4, though. At this point, I'm afraid to do anything to it. I think I'm just going to go as far as tires/sliders/torsion lift/add a leaf/shackles and that's probably it. As it is.. it barely fits in to my garage, height-wise. SO I might wait on the lift.

A full exhaust system sounds like a good idea. What do these things come with? 2"?
 
#8 ·
I'm not entirely sure what to do first. I was originally thinking rock sliders and fresh tires (it seems like 33" tires are the best bet). However, because of the "mint-ness" of the car, I'm a little reluctant to do anything to it at all. I know that eventually the modding-bug will creep up on me and I'll have to do something, though. As for right now, I'm dedicating myself to fixing the minor problems:

I don't think 33 in. tires will fit without some kind of lift. I have 31's on my 89, but my RS model came with 31's and 7 in. snowflakes. (alloy wheels). I do know the standard set up should be 235x75x15 on 6 in. wheels. You can possibly put the larger ties on the standard 6 in. wheel, but the 7 in. would be a better choice.
Thought I'd include a pic. of the 31 in. tire on a snowflake wheel.
 

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#9 ·
Ohh that looks good. I hear they're pretty rare, though. I'll keep an eye for it.

So far I've ordered the Independent 4x HD tie-rods to fix steering slop and ordered 5 BFG KO2's in 31x10.5 for my teensie 15x6 wheels. Depending on how much higher the new wheels lift the car, I might get the Indy4x lift shackes/bolts/bushings and crank the front t-bars to get a 2 inch lift. I only have about 4 inches of space before I hit my garage door (if I remove the roof rack) so I'm playing it by ear.

I'm going to try and get the R12 system reconditioned. I haven't heard the compressor kick on so that might be the issue... or it could be a relay. If R12 is not an option, I'll be going with good ol' R12a or worst case scenario... R134 retrofit.
 
#10 ·
I've also been on the look-out for some sort of rear-sway bar and all I've turned up with are discontinued Addco bars (#461) and a retrofit using a second gen trooper's rear sway. Any pointers or are we assed out on the sway bar front?
 
#11 ·
furiousbob said:
I've also been on the look-out for some sort of rear-sway bar and all I've turned up with are discontinued Addco bars (#461) and a retrofit using a second gen trooper's rear sway. Any pointers or are we assed out on the sway bar front?
You could install one of these Energy Suspension polyurethane bushing kits for the front anti-sway bar:

http://www.ebay.com/itm/Energy-Suspensi ... cX&vxp=mtr

The poly bushings will make the anti-sway bar more effective because they don't flex as much as the stock rubber bushings. Very likely the rubber is all worn out anyway.

Independent4X sells poly bushings for the leaf springs:

https://www.independent4x.com/Isuzu-Rea ... p_134.html

The kit for the rear of the leaf springs is only $23 and the old rubber bushings are probably worn out anyway.

Have seen good feedback on use of poly bushings at the front, and installing the Gen II anti-sway bar at the rear. That may be the best you can do, unless you can find the Unobtanium front bar.

HTH.............ed
 
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#12 ·
Passed SMOG with almost flying colors today. I may have a faulty temp sending unit since my temp gauge reads low (like 1/10th of the gauge). That resulted in a rich mixture and almost threw my numbers. Tech was a buddy of mine though and made sure it passed.

Also got my Indy4x HD tie rods today. Had a little bit of confusion as to which boots to use (rubber or poly) and ended up stacking them (rubber first, then poly on top) and it seems to be working out ok. Steering is MUCH tighter and will be 100% after wheels/tires/alignment next weekend.

I'm also ordering leaf bushings, shackles and FSB bushings from Indy4x some time this week. Here are some comparison photos of the massive HD tie rods:



 
#13 ·
One other thing, is there a FAQ or guide for fluids and capacities? I want to do a full fluid flush (diffs/tranny/motor) and I can't seem to find info anywhere. I've got a Haynes manual en-route but I figured I'd ask here for clarification (and so I can take Sunday to do the fluids).

Thanks in advance!
 
#14 ·
10x30 engine oil in the tranny and transfer case. Differential oil in rear and front differentials. Engine oil , well wide preferances from members here.
 
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#15 ·
furiousbob said:
Passed SMOG with almost flying colors today. I may have a faulty temp sending unit since my temp gauge reads low (like 1/10th of the gauge). That resulted in a rich mixture and almost threw my numbers. Tech was a buddy of mine though and made sure it passed.
The GM V6 models are notorious for low readings on the temperature gauge. IMHO it's a miscalibration between the GM temp sender at the driver's-side cyl head, and the ZuZu gauge. The 4-cyl models read more upscale but the only time the gauge on a V6 rig I owned went to half or beyond was when it blew a heater hose!

BTW the thermostat is supposed to be 195 deg F so make sure the right one is in there. If it is, then that's pretty much what you're gonna get. I do recall towing my boat up I-5 out of Oregon years ago, and the temp gauge was actually up to almost 1/3 scale! And it sat there like a rock, even though I was towing over 2000 lb with my 3.4 going 70. The 3.4 would have been quite happy to do 80 but I didn't need the ticket!

If you're inclined to replace the sender at some future date, I found some on eBay for about half what they want at Rockauto.com. This is for the OE Isuzu sensor, not aftermarket.

http://www.ebay.com/itm/252674958681?_t ... EBIDX%3AIT

It may be an old O2 sensor causing your rich readings. These are notorious for cooling down under prolonged periods of idling, and causing the ECM to drop out of Closed Loop. A heated sensor will give you faster warmups and a more consistent idle.

Check out Geoff's page on this mod: http://members.shaw.ca/howto/ho2s/heate ... sensor.htm

A couple of tanks of Gumout Regane Hi-Miles fuel treatment, which has a high load of the carbon-cleaning chemical PEA, will clean everything out and maybe drop emissions a bit:

https://www.walmart.com/ip/16888905

Last thing, if you have an infrared thermometer you can check catalytic converter inlet & outlet temps and you may find that the cat is dead. I wouldn't be surprised, most of 'em this old have given up the ghost by now. Might give you a good excuse to upgrade the wheezy 1-7/8" exhaust system! :twisted:

Cheers............ed
 
#16 ·
Great info, guys! Thanks a bunch!

I actually bumped in to Geoff's page earlier tonight and I've been reading up on it. I saw a big bore TBI setup for sale on his site and was wondering if those were still being sold. I emailed him to see what's up. It'd be awesome to have a 4.3L TBI bolt-in-able. The Holley's (502.3?) that bolt up to our 2.8L's have been discontinued, if my reading is right.

I think maybe I'll hold off on a Oreilly's brand temp sending unit tomorrow and just do the fluids. Thanks for the link, though! I'll have to add that to my shopping cart.

Also I've been pondering over a 2 1/4" exhaust system. My welding skills are not up to par so I'll be taking it down to my local shop. The only question I have is... what mufflers are most people using for these trucks? I would be expanding the Y-pipe to 2.25 and then running 2.25 through a (probably new, universal) cat and there on down to a new muffler.

Man, there's so much to do and learn but I'm totally stoked about this project. The girlfriend's already asking me to start the roadtrips!
 
#17 ·
Approx 6.3 pints for a manual transmission; approx 1.6 qt for the front differential; approx 2 quarts for the rear diff (note that if you have an LSD you should be adding and LSD additive to prevent clunking - check for Code G80 on the firewall tag); transfer case, 3.2 pints.

A couple of notes, the tranny will shift better with a manual trans fluid like GM or Penzoil Synchromesh, or a Red Line Oils product that contains friction modifiers. A bit of an investment but you'll really like the shifting action.

http://www.autozone.com/motor-oil-and-t ... 65000_0_0/

https://www.redlineoil.com/product.aspx?pid=46&pcid=7

Tranny drain & fill plugs are low & high on the right side of the trans. With drain plug installed, pump oil into the fill hole until oil flows over. Needless to say you need to be level for this to be accurate!

Transfer case uses engine oil as well, use the same weight as the transmission. There's a drain plug at the bottom rear, the fill plug is higher and a bit harder to see but IIRC it's to the pssgr side.

Engine oil, I use Mobil 1 full synthetic in my 3.4. The engine will stay clean as a whistle with minimal parts wear. Not cheap but well worth it. Use an oil filter that's specified to fit a 1990 S10 PU or Blazer with the 4.3 engine. This filter is taller and fits the 2.8 block perfectly. Go in past the driver's wheel well rubber splash guards, it's an easy access to get the old filter out and the new one reinstalled with minimum spillage. Nice to have the larger oil capacity and as I recall it's around 4.5 quarts. Fill to 4 quarts, run it then let it sit. Check level after the oil has drained down and you'll have your own capacity chart for the larger filter!

Here are some of the long filters, I usually use a Wix or NAPA Gold (same mfg line as WIX):

AC Delco - PF52

AMSOIL - EAO23

Baldwin - B35-S

GM - 25171377 (New#-19210286)

K&N - HP2001

Mobil1 - M1201

NAPA GOLD (WIX) - 1036

Purolator - 24011

WIX - 51036

HTH........ed
 
#18 ·
furiousbob said:
Also I've been pondering over a 2 1/4" exhaust system. My welding skills are not up to par so I'll be taking it down to my local shop. The only question I have is... what mufflers are most people using for these trucks? I would be expanding the Y-pipe to 2.25 and then running 2.25 through a (probably new, universal) cat and there on down to a new muffler.
I cut out the "wye" and cut the downpipe on the pssgr's side back to the 1st flange, then installed a cat with 2-2: dual inlets. Which works out great because the downpipes are 2". Run a 90-deg elbow off the flange on the pssgr's side to the cat, and the driver's side pipe needs a couple of angles to get to the other inlet. Of course a muffler shop could probably run brand new pipes from the flanges on both sides to the cat, and make it look real purty/ Mine isn't purty but it works!

The wye is very restrictive, as the outlet is not much bigger than 1-7/8". The way it's built, I don't think you could spread it, either. Huge bottleneck when you're installing a larger system.

With the cat in, have them eliminate the big "kink" in the pipe between cat & muffler; the pipe goes thru the frame x-member hole and the new muffler will hang in roughly the original position. Then you'll have to get 'em to bend a new tailpipe to complete the job.

Here's the parts I'd suggest, the Walker 15022 dual-inlet cat with a 2-1/2" outlet (just use a reducer down to the 2-1/4" exhaust, aft of the cat); Dynomax 17747 long-body muffler, nice n' quiet at speed with a throaty growl at lower speeds & idle:

Here are some links for a cat and 2-1/4" Dynomax muffler:

http://www.ebay.com/itm/Catalytic-Conve ... 0p&vxp=mtr

http://www.ebay.com/itm/Dynomax-17747-A ... Sz&vxp=mtr

This is as large of an exhaust your 2.8 will ever need, and if you should ever want to upgrade to a performance-built "3.2 Stroker" or Camaro/Firebird 3.4, you won't have to change anything, as it'll be perfect for the larger engine, too.

It won't be cheap unless you have a welder buddy like I do, but you'll like the results!!

Added benefit of the Walker cat is that there's an O2 sensor bung built into the casing, so the sensor will get hotter faster and stay hotter. Add that heater O2 sensor mod and it'll be Primo!

All that being said, I don't know what you can get away with in CommieFornia! :evil: If you have to have a certified cat, I guess the dual-inlet cat wouldn't work. You could have the muffler shop modify the wye or replace it with a better junction of pipes, then plumb in the certified cat of your choice with a Dynomax muffer. Have the shop weld in an O2 sensor bung at the outlet of the new/modified wye and it'll work as good or better than the original.

I've added some pics of various wyes I saved during research, maybe one of those would work for you. The first pic is not of mine but another member's exhaust, you can see how the wye pipe sits and check out the great big exhaust pipe going to that itty bitty wye!

HTH........ed
 

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#19 ·
Above posts are as complete of posts as I've seen in answer to a question. Ed Mc, you deserve a double thank you.
 
#22 ·
furiousbob said:
Seriously, I've never received as in-depth of a response from a forum member before. I love this community!!
That's what we're here for! I'm retired so I can devote a bit more time to this stuff. The site has given me so much info in years past, this is just giving it back!!

BTW, everything I learnt was from Jerry L. and Geoff, they are DA MANs!! :twisted:

You may have noticed this is one of the nicest forums on the 'Net, very seldom do the Mods have to step in, no flame wars, etc etc. That's another reason I hang out here, very tiresome having to deal with that kind of drama. Better to just be dealing with ZuZu mechanical drama, eh?? Nor shortage of that! But lotsa fun, too.

Cheers............ed
 
#24 ·
You won't regret the upgraded TBI, but to complete the package you need to upgrade the exhaust. I did it last on my last one and when I did everything else just seemed to work better.
 
#25 ·
hessmess said:
You won't regret the upgraded TBI, but to complete the package you need to upgrade the exhaust. I did it last on my last one and when I did everything else just seemed to work better.
Yeah, you can't uncork one end without doing the other. For max benefit it's got to breathe in as well as it exhausts. The good thing is, the little 60-degree V6 responds very well to the old Hot-Rod techniques such as breathing improvements.

Modifying the air cleaner helps as well. Even flipping the air cleaner lid upside-down makes a noticeable difference.

When I finally uncorked my 3.4, it was like having a whole new engine under there. It was literally choked-off by the OE 1-7/8" exhaust. What a difference 2-1/2" made! But now I wish it had the Comp Cams "252" cam in there, it lost a little low-end compared to the smaller pipes. But midrange and top-end is a killer!
 
#26 ·
Ok so I'm buddying up with my welder friend and we're going to see what the exhaust system looks like after I get tires/alignment this Friday.

Correct me if I'm wrong, but there's only 1 O2 sensor on these OBD1 cars. So far, it looks like I'm doing the dual inlet cat and muffler that Ed Mc. had mentioned. Even though I'm in California, my SMOG guy doesn't give two squirts about visual inspection.

My question is, do I need to convert to a heated 3-wire O2 sensor if I'm going to be relocating the primary 1-wire O2 sensor to the cat's inlet area? If I do need to convert to a 3-wire, is there a link for more info? I've searched the forum and I'm not finding too much info.

Outside of that, my buddy and I are going to go pipe shopping to see what we need. Looks like a couple of 90 elbows for the passenger's side (as per Ed Mc., thank you!) and a pretty straightforward pipe on the driver's side.

I'm thinking I'm going to tackle the exhaust first before I move on to the TBI upgrade. I'm already dropping about a grand on tires so I'm feeling considerably poorer. The HD tie rods didn't help either. :(
 
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