V6 4.3L TBI power ups?

Jerther · August 15, 2004

Hi there!

I got myself a 1988 GMC Sierra 1500 with a '89 4.3L V6 TBI a couple of weeks ago. I really love it, i did some offroad and i was surprised to see where i can go with that truck

The only thing is about on road performance... I remember taking a ride in a S-10 4.3L about same year and getting about the same... "poor" performances.

Then I tried a F-150, around 1995, and found it quite powerful, then got back to mine and... Nothing to say for the first two or three gears (got a 5 speeds manual) but when i get into 4th and Overdrive... I slow down on the smallest hills, and nothing significant happens when i put it to the floor, a "problem" the F-150 clearly doesn't have.

My first thoughts are as follow: My truck is a lot heavier that the Ford, and mine is TBI as the Ford prolly has a Full Injection system which, as far as i know, greatly improves that kind of performance...

I won't talk about MPG...

So I'm now checking if there's anything to do with that engine to get some extra power from it. I checked for a Throttle Body Spacer which is not very expensive and seems a good investment, and then for a performance Throttle Body (something like Holley), then for an Air intake system.

But with all this i'm almost paying more that i did for the whole truck ;) So i ask you ppl, what's the best thing i should do?

OUMike · August 15, 2004

I got myself a 1988 GMC Sierra 1500 with a '89 4.3L V6 TBI a couple of weeks ago. I really love it, i did some offroad and i was surprised to see where i can go with that truck

Fine truck as you'll soon see. I own a 94' with the TBI V6.

My first thoughts are as follow: My truck is a lot heavier that the Ford, and mine is TBI as the Ford prolly has a Full Injection system which, as far as i know, greatly improves that kind of performance...

Yes. The Ford is gonna be multi port, but TBI is still a form of Fuel Injection. There are no Carbs on these motors. I'd be surprised if there was much difference in weight between the two. Actually Fords have generally been the heavier trucks.

So I'm now checking if there's anything to do with that engine to get some extra power from it. I checked for a Throttle Body Spacer which is not very expensive and seems a good investment, and then for a performance Throttle Body (something like Holley), then for an Air intake system.

These 4.3L motors are EXACTLY 3/4s of the 5.7L V8. Therefor all the same concepts apply. Edlebrock has a few parts for these trucks I believe. I've glanced through their catalog from time to time to see what they have. Intake, headers and exhaust could be a good place to start. K&N (not sure if they make a complete system). If your 4.3L looks anything like mine (88 v 94) then you all that plastic duct crap they use to quiet the motor down. I'm thinking of tossing that, but I live in Houston where the climate is hot. I was told that pulling this out woudln't be ideal for colder climates.

Best bet IMO would be to call up the guys down there at Edlebrock and see if they make one of their Performance Plus kits. They usually include intake, cam, lifters and what not, valves and filters. Not sure about all the gaskets.

I won't talk about MPG...

As long as you go with a cam fairly close to factory specs you should see some improvement in MPG with these. I hadda buddy that just did intake and exhaust and gained about 3 MPG. Not to shabby.

Hope this helps.

BTW...They do make Superchargers for these.

Jerther · August 16, 2004

Supercharger eh..... But this is quite a big change and would cost a lot... hmmm, maybe less than that Holley Throttle Body..?

Well, i got another hint here. I was driving yesterday night. The engine was cold. When i press the gaz pedal, at a certain point the engine suddenly looses a lot of power... like if my timing had too much advance, but no pinging. That thing doesn't happen when the engine is at its normal running temperature, or if it does, it is less significant...

Could it be a cheap or faulty gaz pump problem? I may be completely out but i think a bad fuel pump causes that kind of thing...

Oh and by the way... I'm willing to make external changes first. I don'T think i will go as far as changing the valves ;)

I remember, I tried to flip the air intake bowl lid but it didn't bolt in so i just removed it and the filter, then got on the road and see what happened... Well nothing but a weaker engine (almost the same simptomes as above) and the noise coming out of the air intake which i liked pretty much... But i would choose perf against noise

Thanks for the tips

I live in south Quebec, Canada. The fall is coming and the winter is pretty cold...

OUMike · August 17, 2004

Your truck is old. I would definalty do all the proper things to maintain it first, before doing any power upgrades. I have a 94' with lots of miles and that is one of the first thigns I did. I'm a student so I had to do it when I could afford it. When I did do it this is what I did

* fuel filter

* plugs and wires (might wann a do cap and rotor)

* air filter

* PCV valve

* have the AC checked

Sounds like throttle and intake would be your best bet. You can gain power and a little more life from your motor. Call a few muffler shops about exhaust and they can help you pick the setup thats best for you.

I'll be going with a Flowmaster 40 Series Delta Flow (single in - dual out) here in a few months.

Jerther · August 17, 2004

I bought the truck with an almost dead engine so i replaced it. By doing that i did some overall maintenance on it.

From what you said, I replaced the fuel filter and.. that's about that. I've got no AC. I may want to change the rotor and cap, and the wires too... Is there a way to know if they need to be changed or is it only time based?

Also the air filter should be changed, but i would put a completely new air intake system, something like Airaid, anything better than that bowl ;) and something that would make more noise... I had a Dynasty with a V6 3.3L and had a P-Flow on it, and really loved te hear it roaring I would love to hear that 4.3L

Where is the PCV valve? Is its replacement also time based?

Oh and i also had my EGR valve checked and cleaned along with the holes in the manifold.

As for the muffler, mine isn'T replaced yet, I've read about the flow master DF 40, and it looks good, but would it still be good if i just replace the one i have with one like that or i should have to put another tail pipe, or even remake the whole system to see any difference?

I've got one question... Would a throttle body spacer alone do anything or it would have to be placed along with a whole new Throttle body to make a difference? Cause i don'T want to put that thing in and just say hey i've got a spacer in there... look!

Cool Zr2 · August 17, 2004

Take the v-6 out and sell it, then buy a 350 and get an exhaust job, your good to go.

Its a good weekend project.

Jerther · August 17, 2004

It took us 2 weeks to get the old V6 out and have this one running... And don't have the money for a 350... but i like the idea..

But then again, i would seek the same enhancements for the 350 ;)

OUMike · August 18, 2004

Jerther. The PCV valve is gonna be inside your valve cover. You should see a little tube out of one of the covers. Thats it. I don't remember if it just screws out or what, but they are inexpensive. Fuel Filter and PCV are both time based. Unless you begin to see poor performance like low mileage or whatever. Then change it. These are cheap fixes and inexpensive ones.

As far as the muffler goes you could probably just replace the OEM pipe with the Flowmaster DF and use the original pipe work. Most shops are gonna wanna put new pipes in though. I'd just make a few phone calls and see what you can do.

I don't know much about Throttle Body spacers, but if you happen to try it lemmy know. Might be something I wanna consider myself.

Jerther · August 22, 2004

The tube isn't screwed, I just pull and it comes out. I don't remember where the other sides goes though... So, just under the valves cover, under that tube, there's gonna be a valve, and that's what is to be changed.

Oh, and just before I put a new one, is there something that could tell me is the valve i have there is still in good condition?

As for the throttle body spacer... some say it makes a difference... some say it doesn't mush... well, it does make a difference. I also read that it is more efficient on carbs than on TB. I also noticed that all the feedbacks of the throttle body i was checking were for 1997 and newer trucks... Nothing for something as old as 1989

I havent read anything bad about the spacer, except for engines that have a lot of sensors on the injection system... which doesn'T seem to be my case ;)

OUMike · August 22, 2004

Oh, and just before I put a new one, is there something that could tell me is the valve i have there is still in good condition?

Not that I know of man. With me I just noticed a pretty severe loss of gas mileage and poor performance. That however wasn't the only thing that had gone south on mine.

As for the throttle body spacer... some say it makes a difference... some say it doesn't mush... well, it does make a difference. I also read that it is more efficient on carbs than on TB. I also noticed that all the feedbacks of the throttle body i was checking were for 1997 and newer trucks... Nothing for something as old as 1989

Sounds like they are Vortec only kinda thigns. I have a 1994. Maybe I'll try to find one.

Jerther · August 22, 2004

You can have a PowerAid (those who make AirAid) TB spacer for the 87-96 (or is it 97) gm 4.3L's

Isn't Vortec technology doing the same thing as the spacer?? creat an air+gaz vortec so they protuce a better mix?

I know the spacer has 2 main goals: the one i said above, and to insulate the TB from the intake, so it stays cooler

OUMike · August 22, 2004

You can have a PowerAid (those who make AirAid) TB spacer for the 87-96 (or is it 97) gm 4.3L's

Isn't Vortec technology doing the same thing as the spacer?? creat an air+gaz vortec so they protuce a better mix?

I know the spacer has 2 main goals: the one i said above, and to insulate the TB from the intake, so it stays cooler

beats me. I don't really know much about what Vortec really is. But I do know that the pre 95 Vortec V6s...really arn't Vortec.

Cool Zr2 · August 22, 2004

You can have a PowerAid (those who make AirAid) TB spacer for the 87-96 (or is it 97) gm 4.3L's

Isn't Vortec technology doing the same thing as the spacer?? creat an air+gaz vortec so they protuce a better mix?

I know the spacer has 2 main goals: the one i said above, and to insulate the TB from the intake, so it stays cooler

beats me. I don't really know much about what Vortec really is. But I do know that the pre 95 Vortec V6s...really arn't Vortec.

They don't have Multi port injection, but they do have a version of vortec heads, the 4.3's have had then since 87 or 88.

tryn2lrn · August 23, 2004

Change the gears in the rear, put in 4.10s or even 4.56s if you really want to feel a difference. You will run higher rpms and gas mileage will suffer but you'll definetly be shiftin quicker