3.4 engine swap info

Okay, I finally got my 3.4 to replace my wheezy 2.8. I want to keep the factory chev fuel injection. So what all is involved in getting it in and running. I already know about the fuel pump and balaced flywheel, what I'm trying to find out is if I can just get a wiring harness and computer from a 95 firebird (what the motor came from) and wire the motor up, I can think of a few problems like the ignition and the tach and some things like that. I'm not sure what is involved in this job, if anyone's tackled this before and can give me some hints I'd appreciate it.
Thanks
chris

here you go, hope it help:-
http://www.jeepsunlimited.com/forums/showthread.php?s=&threadid=417180&highlight=3.4L+swap

Ravi

rav said:

here you go, hope it helps:

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Lunghd stayed with the carb'd set-up from the XJ, and just bolted it onto the 3.4 instead of fiddling with the FI.
So that write-up won't help on the FI issue, tho it's great for the mechanics of the swap.

One thing occurs to me regarding FI:
The 'puter and wiring harness and sensors will communicate together.
But I think you'll have to run a duplicate set of sensors to operate the gauges. Maybe a 'T' fitting at the temp port and install two sensors.

You'll also have to fiddle with the power out of the ignition, since the 2.8's 'engine circuit' only feeds the ignition.
Now you'll have to feed the ignition, computer, and fuel pump; possible others.
Maybe take the existing ignition lead and feed a couple of relays to then feed the new set-up.

FI cars of the '80's-early '90's were OBD, with codes that you accessed by various means.
Chryco = turn the key three times, then count flashes of the 'engine warning' light.
GM = jump the two sockets of the OBD connector 2-pin connector, then count flashes.
Modern engines (since '96) are OBDII; can't read yourself, but Checker/AutoZone/PepBoys have readers for free use.
THE MID-90'S GM's had 'OBD1.5' with a three-pin connector that can't be jumpered like earlier GM's, yet nobody but GM dealers have the goofy old reader. So, trouble-shooting engine-management issues could be a bitch if you get the OBD1.5 system.

There's an outfit that makes custom wiring harnesses for engine swaps. http://www.injectiontechnology.com
Quite expensive ($400-$900), but possibly cheaper than a junkyard harness in the long run if it's plug-n-play.

Good luck.
-Rick

Lunghd posted this regarding the 3.4 FI (over at JU):

"Just got this reply from DynaTech regarding a standalone harness for 3.4L fuel injection systems.
Looks like they only need the engine harness to do the actual fab-work though you'll still need the donor computer.
I've posted their reply with contact info so you can get in touch with them directly if you need a conversion harness:"

Hi Dwayne
We can setup your EFI engine for standalone, you have to send me the
wiring harness (you dont need to ship the computer)
your price is $230.00 including shipping


DYNATECH MOTORSPORTS
8145 BYRON RD #B
WHITTIER CA 90606
562 945 5300

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Thanks guys, that's loads of help. I'll check my options and post an update of what I plan on doing.
As for tomorrow, it's out with the old engine.
-Chris

Okay, old engine's out. (Anyone want a greasy 2.8? ). Looks like it's steam cleaning time. Also time to go parts shopping, I hate that part.
Looks like the trany needs some new seals, maybe I should just get a whole new trans.
Does anyone know of a better trans that will fit behind my 3.4? I kinda want something with more than 3 speeds, and overdrive would be nice. Maybe a 700?

What about a tranny/transfer case combo from an S10. They came with the 2.8 also and I don't imagine Chevy used the Chryco auto in theirs. I would doubt that it is a bolt in. Probably need to change crossmember and driveshafts, but that lower first gear and the OD would be worth it. Have you seen this page?

http://home.earthlink.net/~jeepcherokee1/Project XJ/Project XJ.htm

Has a lot of good links on the S10. Good luck on the FI and let us know how it all turns out. Lot of us out here still with the 2.8's.

A 700 will bolt up, IF it was built for the 60* V6 pattern.
Most were built for the 90* V8 (and 4.3 V6) chevy pattern and will NOT bolt to the 60* family.

It's longer than your tranny, and you'll probably have to fab a rear mount.

Older 700's were notorious for bad durability, the newer ones had significant improvements. I don't know the transition years from bad to good.

The 700's come with different output shafts depending on whether the original application was 2wd or 4wd.

Yeah, I've thought of that, S10's came with 700's and 231's so I'm pretty sure I could get the 700 and trans/t-case adapter from one of them and it should mount up nicely. A crossmember wouldn't be too hard to fab up.
Another thought is since I'm using the computer and junk for the injection I could try to go with a 4L60E and wire it in, I guess I'll have to check with the wiring company that's going to modify my harness and see if it's a good idea.
Thanks for the link, that's going to be helpfull.

Okay, here's an update for those of you interested in this project.
The new engine is in, I did not switch over to the V-belt pulleys from my old motor since I'm going to keep the MPFI. So here's what I've found out so far.
I'm going to need a high pressure pump, at least 45 psi. The best one I could find was at AutoZone, # E2000, around $100. That's going to have to be wired in line. I'm going to need an electric fan since the new motor doesn't have one.
The wiring harness is at the shop being modified. Once that's done I should be able to plug everything into the motor and wire my existing wires, (temp, starter, alternator, etc...) into the harness. Shouldn't be too big of a deal.
One thing to note, when attatching the motor mounts to the engine block I had to notch a section out of the right side engine mount to accomodate the knock sensor, this was no big deal. Also, the firebird ac compressor will not work with the jeep motormounts and has to be removed. I'm going to have to find a smaller belt. I'll figure something out for the ac later, for now I'll just do without since it's winter.
I'll post more when I get a little more into it.

crimsonride said:

Yeah, I've thought of that, S10's came with 700's and 231's so I'm pretty sure I could get the 700 and trans/t-case adapter from one of them and it should mount up nicely. A crossmember wouldn't be too hard to fab up.
Another thought is since I'm using the computer and junk for the injection I could try to go with a 4L60E and wire it in, I guess I'll have to check with the wiring company that's going to modify my harness and see if it's a good idea.
Thanks for the link, that's going to be helpfull.

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Just a FYI - The 700R4 and the 4L60E are the same transmission. The 4L60E is just the electronically controlled version. They have perhaps the deepest 1st gear of any commonly available transmission. Also they have a .70:1 overdrive IIRC. If you want to beef one these things, the same trans is found in the corvette. You can use all the clutches and valve body from that trans version.

Jared

crimson why not use a 91-96 xj pump?

it should go in your tank and easly be wired. It puts out a lot of presure at least 40 psi IIRC maybe 45!

crimsonride said:

Okay, here's an update for those of you interested in this project.
One thing to note, when attatching the motor mounts to the engine block I had to notch a section out of the right side engine mount to accomodate the knock sensor, this was no big deal.

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Ya can also just put the knock sensor into another available block 'hole' that's threaded the same.

Any clearance issues w/ the oil pan? Looked like there was plenty of room to keep the CamBird pan. What about hood clearance over the SFI throttle valve & intake?

Glad ya are goin' the the fuelie - wish we could have. Anyone wanna buy a complete 3.4L fuelie set up (no ECU)?

:anon:

DeadEyeJ said:

Just a FYI - The 700R4 and the 4L60E are the same transmission. The 4L60E is just the electronically controlled version. They have perhaps the deepest 1st gear of any commonly available transmission. Also they have a .70:1 overdrive IIRC. If you want to beef one these things, the same trans is found in the corvette. You can use all the clutches and valve body from that trans version.

Jared

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Sorry guys, it's been a while since I checked the forum.
I can pick up a 4L60E from the same guy I got the engine from for cheap. It looks like I'll go that route sometime later. For now I've opted to keep my old trans till summer then I'll go for something better.

Re: crimson why not use a 91-96 xj pump?

Ghost said:

it should go in your tank and easly be wired. It puts out a lot of presure at least 40 psi IIRC maybe 45!

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I've thought of that, are the tanks the same? I haven't really looked into that since an inline pump seems easier to do to me. I'll check with Mepco and see if it's doable. The only problem is these dang 84's are so different from every other cherokee I'm willing to be the tanks are different too.

Ya can also just put the knock sensor into another available block 'hole' that's threaded the same.

Any clearance issues w/ the oil pan? Looked like there was plenty of room to keep the CamBird pan. What about hood clearance over the SFI throttle valve & intake?

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Yeah, wish I'd thought of that when I was grinding away at the motor mount.
The pan is definitely bigger but not by much, maybe an inch or so. I don't think there'll be any clearance issues. My jeep is lifted six inches, on a lower jeep it might cause some problems. I'll try to grab some digital photos here soon. Maybe I can take some tomorrow.
Hood clearance might be a problem. I measured this just about a hour ago. The throttle body stands an inch higher than the tops of the fenders. This is made slightly worse with my 1" t-case drop. I'm not sure how much the stock hood raises and I guess I won't till I get it bolted back on and closed. Maybe I oughta start looking at some cowl induction hoods.

Another thing, the stock throttle cable will work fine. I need to cut off the crimped fitting on the end and save as much cable as possible, then I can use a clamp on fitting (I'll get a pic up soon)and slip it right into the throttle body lever. Kick-down might be a little tricky but I think it's going to work out and I think I can even get my cruise to work with it. I'll have to work a little more on that. I did slip the old cable into the throttle body to see how it felt and the pedal is definitely lighter. Should be smoother without the carb.

Well actually......

They look the same. I was just under mine looking and compareing the mounts. Looks like they will work. I'll know more when I get mine out. I'll let you know what I find. Just in case you did not know I'm swaping a 94 2.5L into my 84.

Sounds like fun. This project was supposed to be short-term but the troubles of the fuel injection combined with my rash decision making (buying snowmobiles) has delayed the project some.

Yea so was mine......

Supose to be short term that is.....

But there were other issues under the carpet so to speak. LOL!

Ok here is the dope Crimson!

I just spent the better part of an hour but it fit. I pulled the 84 sending unit out and put a 94 sending unit in. (Those damn rings are a bitch!) If I were you I'd consider it. The sending unit I got was from Egypt1 and a 94 2.5L by the way. He has lots of jeep parts and he has done me right that unit with pump and everything was $50.

So it's an easy swap? The sending unit works the same? I just don't like the idea of having to drop the tank and then if I have a problem with it I've got to do it all over again.
Anyway, if you say it really is the better way to go then that's what I'll do. Give me an idea what it took to replace it.
thanks
Chris