installing LA1 3400 into 1989 Trooper

[89Trooper]

Hi everyone I have a 1989 Isuzu trooper with the 2.8 TBI engine in it.I paid $200 for it knowing it had a blown intake gasket
The engine runs great with 210,000 miles ( which at 209,000 freshened it up with everything other than rings and bearings) so you ask why swap???

Well the Trooper came with 4.56 gears from the factory with that being said at 70mph on the interstate it's doing 3200rpms and at 55mph it's at 2500rpms.
So if I ride the interstate I only get 12mpg per gallon and off the interstate 17mpg and thats shifting at 2000rpms everytime.

SO I want to put a set of 33" tires on it to bring the RPMs down,but I know the 2.8 want have enough power to handle them I will be using 4th gear to much.

So my plan is not to use L32 3400 oh no i'm going with the LA1 3400.

Reasons why I chose the LA1 is,,,,
1st,,, 185hp and 210tq
2nd,,,the starter is on the correct side for my trooper.
3rd,,, I can use the 2.8 distributer and most of the sensors are close to the same location as the 2.8 so want have to do to much wire harness work.
4th,,,I should be able to use the 2.8 exhaust manifolds
5th,,, This i'm sure is going to make you ask why????,but I am NOT going to use the LA1 fuel system nope to much $$$ and work.I am going to smooth out the center section of the LA1 upper intake and mount a 4.3 TBI throttle body on it.And make a block off plate for the 3400 factory throttle body location( I really thought crazy ) about putting two 2.8 TBI throttle bodies on top of it,but I need to see how good the one 4.3 TBI does.

So this Sunday i'm going to pick up my LA1 3400 that was in a 1996 Chevrolet Lumina APV.

I don't think motor mounts will be much problem because my mounts are at the front of the engine on the chasis.
The only thing i'm not sure about is the accessories it would be nice to be able to make my factory accessories brakets work,but i'm pretty sure the LA1 water pump location will screw that up for me. So only time will tell.

Last,but not least your probly wonder why put this much time and money into something I only paid $200 dallors for??
Well the answer is it has a huge amount of room plus the windows are so big it feels like riding in a Bluebird bus and my 3 year old son can see everything because of the big windows. Plus for what ever reason I have grown an attachment to it.

Well people if you have any suggestions or things i'm not thinking about that my be an issue please let me know any help will be grateful.

I will update yall with pics of the progress if yall would like.

Wish me luck
Cliff

[geoffinbc]

Sorry to ruin all you plans. But the engine mounts are different, the exhaust manifolds aren't even close.

Putting a TBI on top of a plenum like that is a HORRIBLE idea. There is stagnant air inside that plenum and that means the fuel will drop out of suspension and fuel distribution would be the absolute shits. Plus 2 2BBL tbi throttle bodies would make for horrible throttle definition. It would be wiser to use 2 2.5L TBI units. You cannot use the 2.8L distributor with a 3400 manifold unless you modify it a lot.

The last issue is your theory that lowering your RPM's will increase gas millage. Well I'm sorry but it wont if you use a larger tire to do it. All your going to be doing is packing more weight and fighting more rolling resistance and air resistance and that would kill the millage right there.

In my opinion the best option is to stroke the 2.8L to a 3.1L and install a cam with the desired operating range right at the RPM you cruise at. You can even get more mileage right now by installing E-Fans, a better air filter or intake system, and by checking your current tire pressure.

[89Trooper]

Junkyard Saturday for research

Well I went to my local junk yard Saturday were there is plenty of LA1 3400 to test theories on.

Man was I disappointed the LA1 intake is wide enough for the TBI,but I busted one open to see inside of it and of course it want work.

Also the exhaust manifolds want work also.

The motor mounts I could have made with no problems,but still doesn't matter everything else want work.

So I am going to follow what BTU said.

I am going to find an aluminum radiator and install one large or two electric fans.

I am going to buy two straight threw CAT convertors one for the CAT the other in place of the muffler.

Then i'm going to buy the 90degree blower cap to go on the TBI and make my own snorkel.

To build a 2.8 will be last resort,the engine I have now runs to good to scrap.
I would find a Rodeo at the junkyard with 4.10 gears and swap the whole rearend to the Trooper and swap the front third members before building another engine.

I would swap rearends and front ends now if I could find a posi 4.10 Rodeo rearend because my rearend I have now is posi which I have to have to put my car trailer and travel trailer in my back yard which has a hill, also to remove them from the back yard too. My 2007 GMC 1500 (Classic) is only two wheel drive and posi,but it just spins in the grass on the hill.

What I am hoping for now is to atleast get 20mpg's off the interstate 55mph average speed before resulting to the 4.10 gears swap.

[Superdave]

grab a 3.4 from a 94/95 Camaro and toss the 3400 top end on it with a decent cam like the H260 from Crane, you might be able to modify some S10 or 3rd gen Camaro headers to fit.

IMO, ditch the TBI/Dizzy and go MPFI.. after a bit of tuning i don't see why you couldn't get 25+ MPG and 200+ crank HP. It'll be a bit of work but should pay for itself after a year or so...

[geoffinbc]

Man I would NEVER trade a rodeo rear end for a Trooper one. The Rodeo rear end is a Gm 7.5" and is not nearly as strong as the Trooper's Isuzu rear end. You should be able to score a newer set of 4.30 gears from a newer model Trooper. They got higher gears because the engines had more power in the later years. late model rodeo's did get D44 rears but weather or not they are a bolt in I am not sure.

If you want a TBI hat that fits the GM throttle body then check out spectreperformance.com they have single and double inlet tops that fit and clear the injectors. They are very heavy duty and built from cast aluminum. I have one on my s-10 and one on my Trooper.

Man maybe your Trooper just needs a tuneup because I get an easy 20MPG hell I get 16 MPG when in 4X4.

[89Trooper]

Isuzu rearends

Only the TBI Rodeo's came with the GM 7.5 and the 1990 newer trucks.

I would only trade for a Dana44 even though I don't want to.

I fixed an issue that I didn't relize I had until it started running rough this week.
The problem was the fuel filter was clogged up. The reason why I didn't change it in the first place is it looked like brand new and also the guy I bought it from said he had just changed it.
So anyway's I put on a new fuel filter and cleaned the idle control on the TBI.
Now I can't even feel her idle she runs so smooth.
I have not used all the fuel in the tank so not sure if I picked up any gas milage,but I do know I picked up alot more power than what I was getting before.

By the way I had already replaced the dist cap,rotor button,wires,and plugs

Also today or monday my two straight threw resonators should be here so i'm going to have them welded in.
By the way in my county we do not have emissions so not worried about that.

I am pretty sure just the fuel filter change should get me more milage and I know the exhaust work will to.

I just know that my 1991 S10 2wd with the 2.8 and 5 speed trans I was getting 26mpg.

I think i'll be getting hopefully around 21mpg to 22mpg at off interstate speeds soon.

[Ed_Mc.]

Remember the Trooper weighs close to 4000 lbs and has the aerodynamics of a brick! The S-10 2wd is far lighter and I expect quite a bit less drag going down the road.

My old '86 2.3 Troop with a Delta cam & free-flowing exhaust would get close to 25 mpg but I'd expect you'd have trouble getting a V6 Troop to do the same.

My old '90 Troop with Hot-Rodded 2.8 would get around 20 mpg on a long trip if driven reasonably. You can build a TBI'd 3.4 with the right cam and probably get close to the same, maybe better.

If you were to use a 'torquer' style cam, 2.8 TBI with 4.3 injectors, and perhaps a 2-1/4" exhaust, your top-end power might be limited but low-to-midrange should be excellent and you could pull a taller tire to get rpm down.

BTW this motor wants to breathe and the stock intake/exhaust are very strangling. Improving the exhaust will make quite a difference by itself and is mandatory to get the most benefit out of any other mods.

Here's some good info for extracting better performance from the little V6:

http://www.4x4wire.com/tech/60degreeV6/

Cheers............ed

[89Trooper]

I am in the process of making my cold air system.

Well this Weekend I went to my local junkyard looking for a 1980's Caddy with the 4100 engine to get the TBI hat off of it.

Then I found a rare find that you 60degree car guy's would love to come across it was a 1990 Pontiac Grand Prix turbo charged nothing had been touched on it yet. So I took the intercooler and all the plumbing I left all the exhaust stuff cause I had no use for it.

I ended up with a wheel barrow load of intake piping,hoses,clamps,and the intercooler for $20.

I will probly use the intercooler on my GMC because it will fit nice behind my grill and I only use this truck for towing my Travel Trailer and car trailer so I feel I can get the most use out of the intercooler on the GMC.

Back to the Trooper I went and bought a new cone filter now I have just been thinking how to make the snorkel without water getting to the filter when it rains.

I have been thinking about not even making a snorkel since I don't plan on going threw anything that will get water inside the cab they just look tuff on a 4x4.I will probly take sheet metal and make my own housing behind the drivers side head lamp.

Now for the gas milage I am getting around 20mpg. I have found that my tripOD is off atleast 5 miles per 20 miles traveled.

I have not done the exhaust yet or the cold air so I will be interested in see what difference is made to my MPG.

Also I feel I have plenty of power to pull the larger tires that is not a concern of mine anymore.

[Canyonero]

I'd like to see what you come up with for your intake. I have a K&N cone on my SFI setup for now. Warm air intake, right next to my radiator! :P It's a temporary anyway...

You can supercharge your 2.8-3.4L TBI setup (for a price of course). Maybe on my next Trooper.

[Canyonero]

Now that my SFI Trooper is nearing completion, I'm planning for a Trooper 2.0 project (funded by a friend lusting for a Trooper of his own... which we already have, it just needs a new engine). A hybrid 3.4L RWD + 3400 might fit the bill.

[geoffinbc]

Oh hey guys I have some CAI intake solutions for you that I added to my site recently.

http://members.shaw.ca/betterthanyoutoo/how-to/tbicai/tbicai.htm

I have it on my S-10 right now and already bought the parts for my Trooper. The difference is pretty impressive.

[89Trooper]

Well i'm going back to the LA1 3400

Well I did the exhaust and it really sounds good at idle,but under driving conditions it sounds like factory.It also improved power.

Ok I have not had time to do the intake yet I will try to do it Sunday.

BACK to gas mileage Well I was mistaken about my tripOD that thing is 100% accurate according to yahoo map.

So with that being said I am still only getting 15-17mpg

The crazy thing is after doing the exhaust I barely have to touch the gas pedal and she goes,but I still only got 16mpg it just doesn't make since

I checked all six cylinders and there all between 100-105 so no loss there which I new it was fine I just wanted to double check.

it is idleing at 700rpm like it is suppose to. You can't even feel it idle it runs so good.

Everything I have done has helped with power and less use of gas pedal,but no change in MPG.
I am starting to thinking that by getting rid of the clutch fan and cold air to the throttle body I will be just wasting my time on a loss cause.

SO I am going back to my original plan with the LA1 3400,but i'm going to use the LA1 3400 computer and have the wiring harness made for plug and go .

If the LA1 3400 will pull around the Chevy Venture and still get 25mpg I don't see why I shouldn't go for it.

So I called a guy that can reprogram the 3400 computer he said I needed to find atleast a 1997 or newer for programming because it is cheaper to program and easier.

The LA1 3400 that I know about people have already took parts from the engine or have already cut on the harness and such.
So i'm on the look out.

So my first question is can I take the upper intake and flip it around so the throttle body will be facing the radiator??

Also I think there is enough room to keep the exhaust pipe routed over the transmission like in the front wheel drive cars.

I will just have to make my own motor mounts which I don't think will be a problem.

Is there anything else that might cause me problems???? if so can you please let me know

[Canyonero]

My vote is still on a hybrid. I don't see any reason to fab motor mounts, exhaust and such when you can just get a block that bolts right in for RWD... But if you think you can do it, go nuts. Take lots of pictures.

[89Trooper]

I will be honest with you I have a friend that has the RWD 3.4 thats been rebuilt he had in his sons 1986 camaro he will sale to me for $125 with all the accessories and wiring harness and computer.

All the 1986 2.8 stuff and computer is whats on the engine the computer is also for the 2.8

if I could take his computer and engine and put it in the trooper without having to have a harness fixed up and such I would put it in.

If I can just use the 2.8 computer and plug it up and go please let me know and I will go that route,but if I can't plug it in and go I would rather go with the LA1 3400

I say all this is because if I put the RWD 3.4 and still have it TBI I want be getting any better gas mileage but if I can use all the fuel injection stuff without having to rig a harness then thats what I'll do.

Please if I can just plug and go with the RWD 3.4 with everything my friend has please respond quikly because I have found a LA1 3400 if I can plug and go then I want buy the LA1 3400 I will buy my friends

[Canyonero]

The easiest way is to pull the MPFI gear off the 3.4L and put the 2.8L's TBI stuff on. Then there are no wiring issues, you just use everything from the Trooper. Keeping the 3.4L MPFI gets a little... different. That's what I did. I ended up having a custom wiring harness built. Relocated the battery to the cargo area (cut away the battery tray to clear the alternator). Putting a flex-a-lite dual 10" electric fan at the bottom of the radiator to I could clear the air intake off the throttle body. You have to relocate the starter to the drivers side (there is a nice drill jig for that), true with any 3.4L swap to Trooper/Fiero. Exhaust manifolds are different, I kept the camaro manifolds and I'll have the downpipes made to match.

Probably some other stuff too. Look to the thread I hijacked for more info.

http://www.60degreev6.com/showthread.php?t=33801

I'll pay your friend double that + shipping for the 3.4L. Please? I need another one.