Tough Question(swap 2.8 - 3800SC)

[cory]

I currently have an '88 cutlass supreme International, 2.8 auto. with digital dash. I want to swap it with a 3800 SC engine from a '93 pontiac bonniville can this be done? besides getting the computer out of it what else do I need? Will this work with a digital dash? Can I use my original trany or is it best to go with a different one?

[Robby1870]

I dont know about that 3800 SC. If your going for power, I would go with the 3800 S/C from the newer GTPs. 1) Its more power 2) its an easier swap, it pop right into place with stock motor mounts. I assume the 3800 S/C Gen I you are referring to might, but the reason I dont think it would, is because that motor was not used in a W-body. If you do a motor swap, you WILL NEED to change trannies. Get the tranny that came with the motor. The 4T60 you have will not handle much torque at all, and you will have a lot from a S/C motor. My advice, though is get he newer 3800 S/C, the swap itself is really easy. The only hard pary is the wiring.

 

Robby

[godofthunder]

does anyone have a write up on the wiring and everything?

 

jon

[Redfox340]

http://www.l67swap.com/

 

More is coming, so I've heard, but here's a start...

 

- RedFox340

[cory]

Would a trany out of a new series II work? would my digital dash interfere with this? (I think the series II trany's have silinoids in them) What year did the series II engine come out and what type of car would bolt right in?Does anyone have the wiring???

[NOHC_WBody]

I've been told that the L67 PCM will drive the digital dash from the Cutty.

 

here: http://l67swap.com/okidedrak.htm

[Robby1870]

Your tranny has solenoids too! The Gen II 3800 S/C can be found in 97-03 Grand Prix GTPs, 97-03 Buick Regal GSs, 97-03 Bonneville SSEIs, Some other Buicks too.

 

Robby

[cory]

Would I guy leave the original comp. in the car, take it out completly, or splice it into the new comp. does the pcm control anything else besides the engine controls? would I have two different aldl hook ups?

[NOHC_WBody]

The L67 pcm controls the tranny/engine, and will drive the dash and other in car stuff. IIRC, there's an l67swap.com member that has started making swap harness adapters to plug the engine harness to the body harness(to drive the dash), and bypass the passkey crap for the later 1st gen owners

I think that bypass just drives the fuel pump directly through an existing connection.

 

I don't know about the aldl connector though.

[Robby1870]

The L67 pcm controls the tranny/engine, and will drive the dash and other in car stuff. IIRC, there's an l67swap.com member that has started making swap harness adapters to plug the engine harness to the body harness(to drive the dash), and bypass the passkey crap for the later 1st gen owners

I think that bypass just drives the fuel pump directly through an existing connection.

 

I don't know about the aldl connector though.

 

Yeah I heard of someone making that interface harness too

 

Robby

[L67wanaB]

Other than the engine, you will need the down pipe, engine harness, the inner axels, and pcm from the donor car.

 

The engine harness will have to be adapted/spliced to interface with the internal harness.

 

You'll need a bigger fuel pump as well.

 

If the donor car is equiped with a BCM/Passkey system, you'll need to do some spoofing or transplant the BCM and Passkey.

 

Since we're talking a 93 Bonbon, it probably doesn't have a BCM. If you go gen II it most likely will.

 

The new PCM will have to relocated and the most popular place for this is where the battery is located. If you go this rout, move the battery to the trunk.

 

I finally got mine in the Lumina about two hours ago and I can already tell I'm going to have to some suspension upgrading.

 

Now comes the fun part ... wiring.

 

More fun stuff.

 

You need to make a new power sterring line using the engine side interface from the 3800 and the opposite end from your existing motor.

 

Make sure you snag the cruise control system from the donor as well.

[cory]

Know one has the exact wiring diagrams layed out for this swap do they? I know I'm not asking for much. What is the difference between a series I and series II? How do I get a hold of one of these harnesses?

[lukee1982]

Know one has the exact wiring diagrams layed out for this swap do they? I know I'm not asking for much. What is the difference between a series I and series II? How do I get a hold of one of these harnesses?

if you are looking for the harness talk to brianteel on http://www.l67swap.com

he is premaking them i think for the 98 l67 (not sure though) check the site out it has how to's and much more

[GnatGoSplat]

The tach will cease to function if you transplant an L67 into an '88-91 w/digital gauges cluster.

I think you could use the old ECM to act as a tach driver and hook it up to just the ignition circuits on the ignition module and it could possibly drive the tach in the digital cluster, but I haven't proven this yet.

[NOHC_WBody]

Dosen't the upgrade cluster use the same type of input signal as the analog one? I wonder why it wouldn't work?

[GnatGoSplat]

No. The digital gauges cluster gets its tach signal from the ALDL in the datastream. The analog gauges cluster gets its tach signal directly from the ignition module.

I don't know why, it might have something to do with the digital gauges cluster being made by Nippon Denso while the analog gauges cluster is made by AC Delco. That might also explain why the pinouts are completely different between the two.

[NOHC_WBody]

w3rd. Yuo da man, Shawn. :worship:

 

I'm gonna do some research on this, about the ALDL datastream, and see what the 97+ L67 PCM offers, in terms of tach data being sent. Besides, I don't want a 5 foot tall tach on the dash of my car after the L67 swap.