85 2.8 4x4 to 3.4 swap help? - S-10 Forum
 
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post #1 of 23 Old 10-17-2013, 11:54 PM Thread Starter
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85 2.8 4x4 to 3.4 swap help?

Ok so i'm new to forums in general, I've been looking everywhere for the right thread but can't seem to find one that meets my needs. I found Jimmykickers thread but the link to his pdf parts list is no good.

I have a 1985 s10 blazer for automatic with the carbed 2.8. I want the 3.4, I don't want to go all out with a 4.3 or v8, more work than i'm willing to put into it at the moment.

I would like to use a 3.4 tbi set up I don't like carburetors. I am mechanically inclined and I have help with me on the more complicated stuff like wiring the tbi.

I would like a full parts list, what can I use from my 2.8, what do I need to get from newer 2.8's. its not currently my daily driver so I can leave it torn apart for a few weeks.

if there is another thread out there with the info im looking for please let me know.

any and all help will be much appreciated.

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post #2 of 23 Old 10-18-2013, 03:55 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

For the 3.4 swap, you will need the following:

1. A 3.4 short block from a salvaged 92-95 camaro or firebird. (I pulled one from a Firebird. Suggestion, if you find one in a scrap yard, then take a battery and a compression tester. Using some jumper cables to get at the starter in case there isn't a key, you will want to check the compression of that block before you waste the time pulling it.) Or, you can look for someone parting out one on craigslist and go from there.




2. Once you get the engine block, you will need to use the following on the 3.4 from your 2.8:
  • Timing cover, water pump, oil pump and oil pan.
  • You will be using the flexplate from the 3.4, so you need the starter for that also.
3. That is all I can think of from the block since you stated that you wanted to go tbi.

On the TBI stuff,



1. Get the TBI sytem from any of the 2.8l s10's that has TBI and the following:
  • The intake, throttle body, and associated brackets and cables.
  • The distributor, ESC module, knock sensor, relays, and map sensor, (pretty much everything that the ECM harness connects to, you want to take)
  • The ECM, BUT, if the ECM is a 1228062, then MORE IMPORTANTLY, ALSO, GRAB an ECM with the number 1227747. Will explain shortly.
  • The complete harness. The best way to do that is to unhook everything, then pull the harness through the firewall from inside the cab. Be careful about the connectors.
  • The VSS. This is a module in in the dash, under the instrument cluster. There is a sensor that plugs into the back of the speedo. The module will either be a yellow or green rectangular box. This sensor sends pulses to the ECM.
  • Find an Astrovan with the 4.3 throttle body and grab the injectors. You can grab the throttle body if you want, but the throttle assembly might be different. I know that if you use the 4.3 throttle body, you will have to have the 2.8 intake bored out to accomodate the larger bores of the throttle body and the butterflies. (personally, I like the low end of the 2.8 throttle body, and the real gains to that larger throttle body is in the high rpm's. I want a truck that runs, not one for race)
  • MAKE SURE YOU EITHER GRAB the emmisions label of the vehicle you are pulling the TBI system from, or, make sure you note the base timing listed. The 3.4 base timing must match because the ECM software has this number programmed into it.
  • You are also going to need an electric fuel pump that runs at least 13 psi. I will provide the part number of the fuel pump that I am running. It's max is 22 psi, but is regulated down to 13.5 via the fuel pressure regulator in the throttle body injector pod.
  • I'd recommend replaceing all the throttle body gaskets at the time you replace the 2.8 injectors with the 4.3l injectors. I bought the 305 tbi rebuild kit and then the throttle body base gasket seperately. If I recall correctly, the 2.8 kit was about $20 more than the 305 and the seperate gasket.....(who kmows.....)
In regards to the 1227747 ECM. The reason I suggest that is because that ECM has more software support than the 8062. The nice thing about the 7747 also is that the pinout of the ECM is the same as the 8062, so no rewiring of anything is required. I STRONGLY recommend the following due to the support for the ECM, (even though Jimmykicker is still using the 1228062 ECM )

Next up is going to a site called www.gearhead-efi.com and reading up. They have a forum specifically dedicated to GM OBD1 and data for wiring and programming. There, you can also find the wiring diagrams you are going to need along with info on what BIN file parameters you can modify.

If the 2.8 system you pull has the 1228062 ECM, note that the software in that ECM is written for the 2.8 engine. To put it simply, the 2.8 tbi system on the 3.4 engine, it will run leaner than it should and the programming in the ECM can only correct so much for the larger displacement, so there will be parameters in the BIN file that will ultimately have to be changed.

If you are willing to learn it, there is an awesome program called TunerPro Rt that you can run on a laptop and monitor the data stream from the ECM during normal driving. When you are at that point, there are quite a few fellas on that site that would happily help you interpret the data and advise you on what parameters would need to be changed in the programming to get the best tune on your engine.

That's all I have for the time being. I do have links posted here that goes to good info about the TBI system. You can search my posts and find these.

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #3 of 23 Old 10-24-2013, 10:07 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

All that document contains is the spec sheet. Most of everything is straightforward. Doing the TBI swap isn't that difficult. Just make sure you triple check everything. Throw away the old relays in the harness too before you connect everything and replace them with new ones. They can be shorted out and cook your ECM and/or harness...Ask me how I know this....I also have a thread on the swap that is pretty helpful I think. I would suggest taking the schematic, cutting out all the wires not related to the EFI and making it standalone and incorporate it back into your current setup....DOn't try to pull dashes and stuff...that's WAAAY too much work.

Let me know whatever you need. Bill (damanx) is pretty knowledgeable on this as well...especially on the EFI stuff. I probably know the 2.8/3.4 about as good as anyone does and the swap, so ask away!

JK



1984 xcab s-10 3.4L GM crate engine 91 S10 TBI swap w bored intake, Edelbrock headers. 2" Rough Country Lift. Custom exhaust, shift kit, e-fan.


EFI swap https://www.s10forum.com/forum/f106/...e-help-513616/

My build thread (3.4L)https://www.s10forum.com/forum/f106/...stions-427168/
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post #4 of 23 Old 10-24-2013, 06:44 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

Appreciate the props James, but there are a couple of other members here that are FAR more knowledgeable than I am in regards to the EFI stuff. I think 34Blazer is one of them, but yet don't know why he doesn't speak up more about it.

As of this moment, I am having to tweak my timing table due to the fact that the timing table I am currently using is working, but it was originally written for a V8, not a V6 60.

I'd go back to the 1228062 ECM for the timing table, but the support for the hacks are not as plentiful as is for the 1227747 ECM.

So it's pretty much a 6 of 1 and half dozen of the other situation.

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #5 of 23 Old 10-25-2013, 10:55 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

I wish I had the time....
It would be pretty wild to install the 3.4 multi port system from a 94/95 Camaro...
Is there anyone that has done this?

S10 addiction:
1)'82 S10, 383, 700R4, Shorty
2) '85 S10, 3.4, 700R4 4x4 stretch cab (Redneck)
3) '90 S10 2.5, 5 speed shorty
4) '91 S10, Built 3.4, 5 speed shorty (Voodoo)
5) '92 S10, 2.5, 5 speed shorty, (Barbie)
6) '92 S10, 2.5 5 speed, Shorty
7) 1979 LUV, Buick 3.8 V6, TH 350 Shorty.
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post #6 of 23 Old 11-01-2013, 09:18 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

that sounds like everything I need thus far and I greatly appreciate everything that has been said.

last question for now, what would I be looking at as far as gas mileage, horsepower and cost of the swap. I heard the 3.4 out of a Camaro are at 160hp, which sounds great compared to my 110hp dog. what little things could I do to boost the hp a little bit. not gunna race or anything would just like a little more power when I need it. thanks again.
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post #7 of 23 Old 04-19-2015, 12:20 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

Alright, finally getting around to actually doing this. i have the 3.4 getting cleaned up debating on if i paint it what color, i've got headers ordered, new valve cover gaskets, intake manifold gasket and rear main seal ( all Fel-Pro of course).

i bought a complete 1986 2wd pickup that wasn't running when i got it. ($450) new fuel pump, key/ignition lock and a can of throttle body cleaner and it runs like a dream. i was tempted of just keeping it the way it was but would have needed to work out some tilte issues (bought it from a guy who bought a property at auction and the previous owners pass away)

i bought for parts on the tbi swap, damanx said instead of using the s10's 1228062 ecm, use the 1227747 ecm, from the 4.3 full size trucks i believe, the truck i bought has the 1227429 ecm? does this one have more support than the 8062 or should i still go for the 7747?
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post #8 of 23 Old 04-19-2015, 12:27 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

Both 8062 and 7747 ecm's use the same pinout.

I started with the 8062 and used it for a short period of time because I had lots of people telling me that I should go to the 7747 ecm.

So I did.

But I went back to the 8062 ecm due to the fact that there is no BCC written for a 7747 that was on a 60v6.

All though the 7747 has a lot more parameters in TunerPro that you can edit, I found that it was TOO much, especially if you don't know what it all means.

The 8062 with the BCC already written for the 2.8 was much easier to go back to.

I'd have to look at the bin file for the 7429 and then the wiring diagram for it to see if those interchange.

I'll get back to you on that, but I STRONGLY suggest sticking with the 8062 to start.

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #9 of 23 Old 04-19-2015, 12:47 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

Thank you for the quick reply! I'll start looking for an 8062 then.

Do you know where I can find a wiring diagram for the efi stuff? Ive looked and haven't been able to find much.
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post #10 of 23 Old 04-19-2015, 12:50 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

Here:

http://www.gearhead-efi.com/Fuel-Inj...Information-4E

if those are hard to read, then use the pics listed in this thread:

http://www.gearhead-efi.com/Fuel-Inj...Information-42

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #11 of 23 Old 04-24-2015, 01:10 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

Deathpheonix99 has some pretty good diagrams on his signature too and they are really accurate and S10 specific. Word to wise. Study them thoroughly before attempting this. This ought to be a pretty easy setup for the EFI since you have a running truck to pull from.

You going to put the carb setup on the 86 or part it out? Since it has title issue it probably isn't worthwhile.

The 86 has the correct front cover if you are going to keep running V-belts too. It will mount to the 3.4 just fine. Course I'd do away with V-belts and go 87+ if I were you. That 86 cover will sell easy on here if you part the truck out. Are you planning on running the 4.3 TBI on a bored intake? Damanx is using the 4.3 TBI with the 4bbl top with the Edelbrock intake with good results too. I have a stock bored out intake with the 4.3 TBI on it.

Good luck man. I did the same thing you did. Bought the parts etc and got around to it like 2 years later. Haha!

Bill...any way you could build that cable for me ASAP? I'm getting the itch to start tuning this girl.



1984 xcab s-10 3.4L GM crate engine 91 S10 TBI swap w bored intake, Edelbrock headers. 2" Rough Country Lift. Custom exhaust, shift kit, e-fan.


EFI swap https://www.s10forum.com/forum/f106/...e-help-513616/

My build thread (3.4L)https://www.s10forum.com/forum/f106/...stions-427168/
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post #12 of 23 Old 04-24-2015, 03:29 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

Hey James,

Will do that tomorrow. You have the ALDL diagnostic connector hooked up?

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #13 of 23 Old 04-24-2015, 04:50 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

I don't think I can use the front cover because the donor is 2wd I have a 4x4. Or does that matter? I know I can only use 4x4 oil pan.

I can get a bonded title ($50-100) for the donor truck and if I do get it titled and registered I would put the carb stuff on it so I can move it easily and then maybe down the road do a V8 swap.

I've got plans to build my golf cart after my blazer is done so we'll see what happens.

As far as the serpentine setup I would love do that but the only local 4x4 blazer I found being parted out they won't part the engine out. And I always have bad luck at the pick n pull.

I'm not sure if I'm going with the 4.3 tbi or not. I hear that's mostly for top end power which im probably never going to use. It was my grandpa's truck so it gets driven like one lol.
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post #14 of 23 Old 04-24-2015, 06:30 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

I've noticed better mid-range response going from the 2.8 throttle body to the 4.3 throttle body, but I've had to go in and retune the VE tables in the programming to compensate.

1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #15 of 23 Old 04-24-2015, 09:58 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

Which vehicle should I pull the 4.3 tbi from? Read a certain year astro doesn't involve any modification for the cables.
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post #16 of 23 Old 04-24-2015, 10:31 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

I don't remember seeing the 4.3 throttle bodies in the astro's that had the same bracket, (the part attached to the throttle shaft), as used by the s10's.

look at the following picture, it's what you will need:


1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.
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post #17 of 23 Old 04-27-2015, 09:43 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

Z, the front cover is the same. Only the oil pan is different.

The TBI cable thing is correct. The Astro has the bracket in the same place without doing any thread tapping, but you will still need the correct throttle cable bracket, linkage or whatever you call that damn thing. I took a grinder and ground off the bump on the S10 2.8 one and did the same on the 4.3 one. The bracket will fall right off the shaft. Place it on the Astro one and tack weld it on. One spark from my arc welder did it fine.

Unfortunately that is the only way for it to work without guessing on the geometry and I think you'd be better off going as close to stock as you can. The Astro cable bracket won't work.... The 4.3 S10s used a different bracket altogether than their 2.8 counterparts so those won't work (easily) either which is just lovely.

In Bill's picture above if you see the black bracket on the left. Make sure the one you grab has those three bolt holes. I don't think the Astro uses them but make sure they are tapped at least.



1984 xcab s-10 3.4L GM crate engine 91 S10 TBI swap w bored intake, Edelbrock headers. 2" Rough Country Lift. Custom exhaust, shift kit, e-fan.


EFI swap https://www.s10forum.com/forum/f106/...e-help-513616/

My build thread (3.4L)https://www.s10forum.com/forum/f106/...stions-427168/
Quote:
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I had to cut my nut in half .
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post #18 of 23 Old 07-26-2015, 07:34 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

Ok, everything is coming together slowly, I have the 4.3 tbi from a 91' astro. I called around for quotes to have the intake bored to match. Only 1 shop in my area was willing to try it. Quoted me almost $200. Says it's based on the time it would take to set it up on the mill. Talked to a buddy of mine and said to just use a die grinder to get my size then use a boring tool to smooth it out.

As far as the serpentine setup, the yards around won't sell just the brackets I have to buy the accessories accompanied with them, costing me another $300 for everything. Is it possible to fabricate the current brackets? I'm a fitter/welder by trade so it shouldn't be hard to make, just not sure if anyone had tried it.

Where can I get key switch power for the fuel pump?

Thanks for all your help you guys are awesome!
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post #19 of 23 Old 07-26-2015, 11:38 PM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

or could i use the brackets from the 3.4?
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post #20 of 23 Old 07-28-2015, 10:24 AM
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Re: 85 2.8 4x4 to 3.4 swap help?

According to Max the Camaro accessories will work...You will have to run an electric fan however because the Camaro pump doesn't have one. You might be able to still run it on the s-10 pump though to get around that...Not sure.



1984 xcab s-10 3.4L GM crate engine 91 S10 TBI swap w bored intake, Edelbrock headers. 2" Rough Country Lift. Custom exhaust, shift kit, e-fan.


EFI swap https://www.s10forum.com/forum/f106/...e-help-513616/

My build thread (3.4L)https://www.s10forum.com/forum/f106/...stions-427168/
Quote:
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I had to cut my nut in half .
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post #21 of 23 Old 07-28-2015, 06:42 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

Quote:
Originally Posted by Mad Max View Post
I wish I had the time....
It would be pretty wild to install the 3.4 multi port system from a 94/95 Camaro...
Is there anyone that has done this?
I am doing exactly that with my truck, it isn't nearly as bad as most people think it is. I'll be going from the 8062 ECM to the 16196397 Beretta/Camaro ECM.

Mostly it'll just be untaping the harness in the truck, coaxing out every wire connected to the ECM, and then laying back in the wires that came from the Camaro harness. I may decide to extend/shorten some wires just make things a neater fit but it' not really that many wires unless you are running the automatic transmission (4L60e with the camaro ECM)
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post #22 of 23 Old 08-10-2015, 06:40 PM
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Re: 85 2.8 4x4 to 3.4 swap help?

Hi, I need advice desperately. Here's my situation. I have an 86 s15 4x4 with a 2.8 and 5 speed manual. I want to convert to a 4.3 with automatic trans. What I've done is bought a 1998 Jimmy blazer with the "W" series 4.3 vortex attached to the 406LE or something like that transmission. Can some one tell me what year and model of tranny and transfer case and or engine I can hook up to the existing transfer case on my 86 s15 4x4? Did I buy the wrong donor vehicle? I will be relieved when I know what I should do. Thanks in advance and I look forward to any help I can get.
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post #23 of 23 Old 09-08-2015, 11:10 AM Thread Starter
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Re: 85 2.8 4x4 to 3.4 swap help?

I'm having a hard time tracking down an oil pan from an 87+ 4x4 2.8. I know the isuzu rodeo are basically blazers with 3.1 v6, will an oil pan from that car work? What years should I be looking for?
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