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91 Trooper meets 95 3.4 V6, shotgun wedding!

Posted By: Oscar73

91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/21/06 04:37 AM

Hey folks, I've been lurking around here for awhile, doing searches and hunting down as much info as I could about 1st generation Troopers, since I picked one up for the whopping sum of $400 to replace my 73 Suburban as a daily driver.
This Trooper showed signs of having head gasket problems early, so after I'd looked around here, I managed to pick up a 3.4 for the Troop, figuring to swap it in later, when a good chance showed up.

Well, it seems like there's NEVER a good time, as the head gasket problem resurfaced last week, and I have to drive to California in two and a half weeks, so it's engine swap time!

I'd PM'ed Ed Mc, and he sent all the swap info he'd accumulated (Thanks Ed!), but a couple questions. Everything I read mentions dropping the front axle center section by undoing 4 bolts. What size are these? Nobody mentions that. Having the bare bones in metric tools, if there's something I need, I'd sure like to know.

Also, I picked up a 4.3 throttle body w/injectors, and all the plugs match the 2.8... is this a trick? LOL! I haven't quite understood the posts on this, as it seems like everybody has a slightly different throttle body.

Enough for now, I can see eyes glazing over...but thanks in advance for any advice and/or help, and how come there's so many Isuzu guys in Washington?

Jim Sorenson
Posted By: CPOM

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/21/06 06:09 AM

It would be wise to have aleast metric impacts, and 3/8 drive 6 point metric deep sockets at minimum for working on the isuzu nothing else is really special about them that common metric tools won't fit. You might need a few big sizes for pinion nuts, torision bar bolts and driveshaft flanges (27-33mm) but the rest are small.If you search under 4.3 and my username you can see some pics I took when I did my throttle body swap. Good luck.
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/21/06 07:56 AM

The impact sockets are something I never would have thought of... since I've never owned an impact wrench, but I've broken enough Craftsman sockets to make it worth getting some. I've got a regular assortment of sockets (1/4 & 3/8, both deep and reg, 12 and 6 point) a handful of open/box wrenches and really big hammers! Just wish I had little Japanese hands.Just getting the spark plugs out for a comprression check was an adventure! I'm used to huge underhood spaces on mid-70's Chev trucks...I'll take a look at the throttle body stuff, thanks!

Jim Sorenson
Posted By: Ed Mc

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 02:57 AM

Jim, those bolts take a 22MM socket. I had received a Stanley "Professional Grade" impact socket set for Christmas and put it to good use on the 3.1 project. This is a set of 11 1/2"-drive metric deep sockets in a handy-dandy carrying case, ranging in size from 10MM to 24MM. Probably came from Lowe's but I expect Sears has something similar. One conspicuous absence in the Stanley set is a 15MM size, so you'll need one of those, too.

You might also consider picking up a set of metric Gear Wrenches from Sears etc. I usd the Heck out of mine and they're invaluable for getting into those xtra tight places on the 'ZuZu.

And BTW, didn't you know that the PNW is the Isuzu 3.4 Swap Capital of the U.S. ??? <img src="/forums/images/graemlins/patriot.gif" alt="" /> And the home of the Non-Rusting Isuzu !!!!! <img src="/forums/images/graemlins/nana.gif" alt="" />

You might also want to pick up a can of PB Blaster penetrant from Wal-Mart etc as those Big Honkin' frame-mount bolts probably need soaking. Several of mine were so frozen to the inner metal spool of the bonded rubber mount that only an impact wrench was able to bust the bolt loose from the sleeve. Try holding an impact wrench up for about 20 minutes while busting away at full force & 110 psi, and you can just imagine the fun time had by all! <img src="/forums/images/graemlins/zombie.gif" alt="" />

You may also wish for a very stout 1/2" breaker bar to get other reluctant bolts/nuts loose.

On your 4.3 TBI, you may have lucked out and got one that has the same type of connector for the T.P.S. Later TBI's have a different plug which requires replacing the T.P.S. or rewiring the plug.

You will need to do mods to the throttle linkage and probably vacuum port connections but all of the GM TBI's are very similar so you shouldn't have much difficulty with the mods if you read up on the existing mods FAQ's.

P.S. on the tight spaces, be glad it's not a GM FWD'r that requires jacking up the motor or removing a lot of stuff just to get the plugs out!!!!

HTH & Happy Swapping........ed
Posted By: RubyTrooper

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 05:27 AM

Quote

Also, I picked up a 4.3 throttle body w/injectors, and all the plugs match the 2.8... is this a trick? LOL! I haven't quite understood the posts on this, as it seems like everybody has a slightly different throttle body.


Hey, Jim, what make/model/year did you pull that 4.3 TBI from? I am going to be searching for one soon too. <img src="/forums/images/graemlins/smile.gif" alt="" />

Oh, and really like your thread's Subject line! <img src="/forums/images/graemlins/lol.gif" alt="" /> Good luck!

Jim
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 09:02 AM

Quote
Quote

Also, I picked up a 4.3 throttle body w/injectors, and all the plugs match the 2.8... is this a trick? LOL! I haven't quite understood the posts on this, as it seems like everybody has a slightly different throttle body.


Hey, Jim, what make/model/year did you pull that 4.3 TBI from? I am going to be searching for one soon too. <img src="/forums/images/graemlins/smile.gif" alt="" />

Oh, and really like your thread's Subject line! <img src="/forums/images/graemlins/lol.gif" alt="" /> Good luck!

Jim


Jim,

I had to go search through my email as I forgot where the TBI came from...'90 Astro 4.3 and I found it on eBay. Ten bucks. That's the best I can do there. In lieu of running to the machinist (who's only 6 blocks away, but slow), I may try the TBI spacer to deal with the intake bore difference. Since I've got all the plumbing out, it may speed things up. Yeah, I was wigged out when all the wiring plugs matched! I still think it's a trick.

And Ed, this Troop's from Pennsylvania, but is almost completely rust free... one big scab right behind the Passenger side rear door, where the roof meets the main body.

I've gotten almost everything cleaned off the front of the motor, the driveshafts and crossover pipe unbolted, tomorrow's project is the starter, trans lines, and bellhousing bolts...

Oh, and Sears is having a sale on Craftsman tools. You get a free red canvas tote, plus 10% off anything you can fit inside if you go over $20... yah!

Now to borrow an impact wrench.

More later!

Thanks,
Jim
Posted By: CPOM

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 06:19 PM

Quote
Just wish I had little Japanese hands.Just getting the spark plugs out for a comprression check was an adventure! I'm used to huge underhood spaces on mid-70's Chev trucks...


The 2.8 is an american engine nothing Japanese about it, even thoug hit uses metric fittings. I can't imagine what you would call an easy engine to work on if you think these GM engines are tight, my 3.1 had plenty of space everywhere to do what ever you needed done. What do the 70s engines do, remove the spark plugs for you?
Posted By: onebadtrooper

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 06:27 PM

I know what he means. Even I have some trouble. Its a pain getting some of the spark plugs out, and setting the timing.
My dads 01 gmc is pretty BIG in the engine conpartment. The older chevy trucks are WAY easy to work on!!!Not many wires or hoses in the way.
Maybe the pickups are alittle bigger??? <img src="/forums/images/graemlins/cheers.gif" alt="" />
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 02/22/06 10:41 PM

Quote
Quote
Just wish I had little Japanese hands.Just getting the spark plugs out for a comprression check was an adventure! I'm used to huge underhood spaces on mid-70's Chev trucks...


The 2.8 is an american engine nothing Japanese about it, even thoug hit uses metric fittings. I can't imagine what you would call an easy engine to work on if you think these GM engines are tight, my 3.1 had plenty of space everywhere to do what ever you needed done. What do the 70s engines do, remove the spark plugs for you?

Almost. The engine compartments are so big on the 73 and later Chevy/GMC's, you can actually climb in, close the hood and keep working, if you have one like mine, with a small block V8, power steering, power brakes and no other options.The biggest problem there is being able to reach the engine without having to use a stepladder to get to it!

Jim
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/14/06 08:41 AM

Well, it's in and running! Not bad for a one man show, working out in the alley behind my business, working afterhours, and breaking everything down every night! Too many creeps in the alley to leave anything out but the Troop...

I'll tell ya, the guy who makes a 15mm distributor wrench will be MY hero...that's one blocked-up bolt! Thanks to Sears, though, a 15mm universal socket barely got in there.

Didn't put the 4.3 throttle body on, just the injectors. Haven't had the Troop on the road yet, so, I can't tell you about any performance gains. Although, I'm sure I'll get a little better milage without that six feet of skid plate! What can I say, my dad was into Jeeps in the late 60's and early 70's... Jeep clubs <img src="/forums/images/graemlins/zombie.gif" alt="" /> Me, I'm into nitro-burnin', ground-poundin' front-engine Top Fuelers... and a half-size replacement for my 73 Suburban...

Thanks to Ed Mc and all the others who posted their collective wisdom. The Search feature became my best pal there for a while, and killed a LOT of trees!

Now if I could only figure out the rapidly flashing "Check Trans" light, but it's raining, I'm inside, and it's almost midnight! Tomorrow will have to do!

Jim Sorenson
Posted By: RubyTrooper

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/14/06 12:55 PM

Congratulations Jim! <img src="/forums/images/graemlins/cheers.gif" alt="" /> Now, where are the pics of the new engine/install?! Would like to see it.

Quote
Didn't put the 4.3 throttle body on, just the injectors. Haven't had the Troop on the road yet, so, I can't tell you about any performance gains.


Now, I've not done the 4.3 TBI swap yet, but, with all of the reading that I have done (and may remember correctly or incorrectly) did they not use the 2.8 injectors in the 4.3 TBI? Or, was that, don't use the 4.3 injectors in the 2.8L, but use the 4.3 injectors in the 3.4L? Can someone clarify this? <img src="/forums/images/graemlins/notooth.gif" alt="" />

Jim
Posted By: Ed Mc

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/15/06 05:16 AM

Jim, you can run a 4.3 TBI with either 3.4 or 2.8. A stock 2.8 might be a bit rich with 4.3 injectors so usually you'd put the 2.8 injectors in the 4.3 TBI.

For a 3.4 application, you need more fuel so you'd use the 4.3 TBI as is.

If you were to stick with a stock 2.8 TBI on a 3.4, you'd get lean surging on warmup. Installing 4.3 injectors in the 2.8 TBI's injector pod will cure the lean surge but you're limiting the midrange and top end of the 3.4 'cause it wants/needs more air/fuel.

I used a Holley Big-Bore TBI (roughly the equivalent of a stock GM 4.3 TBI) on my old 2.8. That motor was hot-rodded with larger exhaust, bored intake, jacked-up timing, flipped lid/K&N, and 1.6:1 roller-tipped rocker arms. It ran quite well with the Holley but was just a wee bit "over carbureted".

Putting a larger TBI on an otherwise stock 2.8 would be overkill, since unmodified this engine just can't flow enough air to achieve significant HP gains.

Once uncorked at both ends, using Good Old-Fashioned hot-rodding techniques, it'll really wake up.

Anyway, hope this clears it up a bit.........ed

P.S. Other Jim, Good Job! on the swap. Now get'er run-in, tweaked-out, and enjoy the ride! Your ECU will take a while to adjust to the new motor, and you can pull trouble codes out of your auto tranny's computer to see what's going on there.
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/15/06 06:20 AM

Ed,

Thanks! You've been a big help with this here project. What I did was this... put the 2.8 TBI on the 3.4, but with the 4.3 injectors to compensate for the greater airflow of the 3.4, which would run too lean with the 2.8 injectors... whew! I read it on this site, anyways... I have a stack of printouts on this swap! Besides, I didn't have time (or the right parts at the time) to rebuild the 4.3 TBI, or bore out the intake.

As far as pulling codes, I haven't the faintest. I can't seem to find pictures of wiring, diagrams of where to look, instructions that make sense... all I know is the CTL doesn't come on for approx 20-30 seconds after starting, starts blinking really fast (2-3 times a second) and by whacking the throttle, it goes off until the revs drop.

Duh. And I looked under the dash for the trans box (from the other post) and I haven't a clue. There's nothing under there that says "transmission" anywhere that I can see. Mr. Analog is lost here.

I think I'll go crawl underneath and look for unplugged wires that I may have missed, again. If I can't find an answer tonight, I may have to drive this thing to Cali with a piece of electrical tape over the CTL...

Other Jim
Posted By: RubyTrooper

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/15/06 02:39 PM

Thanks Ed! <img src="/forums/images/graemlins/cheers.gif" alt="" /> Your answer to my question is concise AND thorough. I really appreciate your post.

Jim
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/15/06 07:47 PM

I'm a dope, officially. Two sets of wires, running along the left side of the intake, ending with large washers, calling out to be grounded - weren't. Bolt on the back of the left head, w/braided ground strap attached, when the two wires from the intake manifold loom were bolted down to the back of the left head - SHAZAM!

No more blinking Check Trans Light.

I saw that at like 1:30 this AM, but wasn't ready to go there.

Now you know, check all your grounds!
Posted By: randii

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/17/06 03:15 AM

I'd bet that a 5/8" offset distributor wrench would work on that 15mm bolt... if not, maybe a crow-foot socket on an extension?

Randii
Posted By: Oscar73

Re: 91 Trooper meets 95 3.4 V6, shotgun wedding! - 03/22/06 07:30 AM

Quote
I'd bet that a 5/8" offset distributor wrench would work on that 15mm bolt... if not, maybe a crow-foot socket on an extension?

Randii

A 9/16 distributor wrench, a grinder, a file and I'd have been in business...except my files were too wide, my grinder was elsewhere, and my machinist pal down the street had gone home. Oh, and Sears was out of 15MM crow's feet attachments. Trust me, I looked. But a Craftman 15 MM Universal socket/12"extension, (not a socket/universal joint/extension) worked just dandy.

Update: Just returned from the trip from Seattle to Bakersfield, CA and back. 2270 miles. Haven't figured out the milage yet, but for having one day from firing up the conversion to hittoing the road and driving 1100 miles, everything went pretty doggone well. A couple exhaust leaks (retightening bolts and nuts worked wonders), do NOT overfill the auto trans and drive 85 MPH... it'll puke the fluid out all over the exhaust! Smoke everywhere. Looks pretty bad threading the 99 between semi trucks...still have an issue with the TPS (trans position sensor), as 4th gear (OD) can only be achieved by moving the shifter between D and Neutral, and holding your mouth just right.It's just too tight in between the exhaust & torsion bars to get into and adjust without jackstands or a lift... I did drive up on a curb Friday AM and managed to get it a bit better. But there was a ton of rain, too, and that kept me out from under.

Used some oil, but I may have underfilled at the start, so it may be a non issue.

Anybody got some 4:10's for a 91 Trooper they want to get rid of? I need higher gears... maybe a set of chevy truck wheels with 265 or 275/75/16's or 17's.

Jim Sorenson
Posted By: badaddidude

Check Transmission light 4L30E trans - 05/05/16 01:43 AM

After roaming though the various pages, I noticed that there were some questions about the "check trans light" flashing on the 4L30E trans. The trans goes into "limp" mode, no power...
Many times you will find that the fluid is scorched or oxidized. Half a can of Berryman's Chemtool B-12 and drive it for a few miles usually stops the problem caused by sticky valves or solenoids. Change the fluid and you are good to go.
Posted By: 4x4Wire

Re: Check Transmission light 4L30E trans - 05/05/16 03:30 AM

People often take the auto transmission for granted and don't realize it also needs a little tender loving care -- as in a periodic change of fluids to keep things in good working order. Thanks for the information point and reminder...
Posted By: Jim_Paget

Re: Check Transmission light 4L30E trans - 07/31/16 01:39 AM

Quite often the limp home mode is generated because of a broken wire in the harness.
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