Jump to content

2.8 to 3.4 lq1


Nas Escobar
 Share

Recommended Posts

Has anyone done this?

 

I ask because I picked up an 89 base Regal and have a full lq1 and trans with harness. Thinking bout swapping out the 2.8 for the lq1.

 

Anyone else done it? What woulf i have to mod to get the car to run normal. All help is appreciated

Link to comment
Share on other sites

Swap the MEM-CALs appropriately.  But seriously, what would possess you to do something like that?  Bit of a masochist?

 

As much as the LQ1 is a thing to avoid I'm stuck with one with 93k in my Lumina. Thing is I ended up wrecking my Lumina and it's worth more to fix than what the car is worth. I got the Regal for a steal ($100). It runs, but it has issues staying that way. Right now it's not running, seems like it's not getting fuel. Added a gallon and it will crank but it seems it's not getting fuel. Long story short, I want to get the 2.8 running but I also need a place to put the LQ1 in. I know someone who has a 95 LQ1 that's dead but we're not sure how to go about using a 93 engine. Just seems easier to drop the cradle and put it in a pre 94 car (since 94 and 95 have added sensors for the funky OBD 1.5 it runs).

 

Anyways, I don't have to mess around with the C100 in order for the Regal to act normal?

Link to comment
Share on other sites

I think the biggest issue may be the transmission wiring?

 

It'll be best to grab a wiring diagram for both cars. The plugs I'd be most concerned about are

C100, ecu and trans.

 

You might be able to use the regal harness and just add the wiring for the trans. As I believe all lq1 got the electronic trans vs the vacuum operated regal trans.

 

 

You also may be able to use the lumina harness and drop in, although my experience with the 89 cutlass harness vs the 91+ harness is they don't match at all and you need to add 2-3 power wires and 5-6 grounds.

 

But I'd start with the wiring diagrams first and compare. I think the trans wiring will be the biggest hurdle but might be easily added to the regal harness so no other changes needed.

 

 

Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

First is the LQ1 a manual or automagic trans ?

 

Second the 89 would have a 4T60 and the 93 (if automatic) would have a 4T60E. Wiring and computers  are very different.

 

However if making a transplant, I suspect you could do a full transplant, cradle, wiring harness, computer, and all. Just have side by side and move one thing at a time.

 

Anything can be done.

Link to comment
Share on other sites

I think the biggest issue may be the transmission wiring?

 

It'll be best to grab a wiring diagram for both cars. The plugs I'd be most concerned about are

C100, ecu and trans.

 

You might be able to use the regal harness and just add the wiring for the trans. As I believe all lq1 got the electronic trans vs the vacuum operated regal trans.

 

 

You also may be able to use the lumina harness and drop in, although my experience with the 89 cutlass harness vs the 91+ harness is they don't match at all and you need to add 2-3 power wires and 5-6 grounds.

 

But I'd start with the wiring diagrams first and compare. I think the trans wiring will be the biggest hurdle but might be easily added to the regal harness so no other changes needed.

 

 

Sent from my iPhone using Tapatalk

 

My idea was to simply drop the 93 cradle down and raise it where the 89 cradle used to reside. I'm not sure if it's easier to make the 89 harness match the 93 or use as much 93 as possible then figure out the body side of things to get stuff like the ignition, turn signals, etc working. I'd prefer using the Z harness over depinning and repinning.

 

I have 2 W body bodies so this is moreso an idea to save a low mileage LQ1 rather than the typical situation where someone buys a car and doesn't want the engine in it so the typical issue of finding a "donor car" isn't so much the case here. I have a wrecked Z and a non rusty Regal Limited that needs a paint job but otherwise straight body.

 

As far as the ECU goes, I have it, a 92 Z computer I put in the 93 since the computer in the car was bad (idle issues). It's the C100 (the 4 plugs in the ECU I assume) that I need to figure out. That and if I need to swap radiators over too. I know my 93 has external fluid coolers which I assume the 89 doesn't. I'd also need to figure out how to keep the R12. I'd like to keep it R12 if possible.

 

First is the LQ1 a manual or automagic trans ?

 

Second the 89 would have a 4T60 and the 93 (if automatic) would have a 4T60E. Wiring and computers  are very different.

 

However if making a transplant, I suspect you could do a full transplant, cradle, wiring harness, computer, and all. Just have side by side and move one thing at a time.

 

Anything can be done.

 

Slowamatic sadly. I wish I could find the 284. Would make for a nice sleeper. Grandpa car that pulls off hard at the line.

 

I'm familiar 91 had the electric 440T4 whereas the 89 has the TV cable and all that fun stuff. I wasn't asking much about those because my idea to make this as painless as possible is gutting the cradle out of the 89 and leaving just the rack and pinion and raising the 93 where the 89's used to be. I just don't know how to make the ignition and all the fun stuff in the car work. I assume the C100 would control some of that.

 

I guess long story short is I know a guy who can do this swap mechanically since I assume the cradles didn't change much over the years but he's not versed in electrical stuff so that's where I'd step up and mess around with the wires to make it all work.

Link to comment
Share on other sites

Trannys were a continuous improvement process with many TSBs over the years. 440T4 to 4T60 was just a name change but the 4T60E (91) was quite improved so I'd suggest just swapping the whole powertrain and computers then the only things that might be a concern would be whether the dash works properly and the ABS or lack thereof.

 

Ryan at gmtuners.com may be able to help.

  • Like 1
Link to comment
Share on other sites

C100 is the firewall plug on the passenger side

 

 

I'm not sure if the luminas changed the engine harness side of things but I know the 88-90/91 cutlass is different than the 92+. The biggest difference is the aux battery terminal on the 88 atyle is all built into the main engine harness. On the 92+ it is a seperately harness all together.

 

When I swapped the 98 Monte Carlo harness into my 88 cutlass I had to add another fuse box and relays to make the car run.

 

It's not terribly difficult you just need the wiring diagrams for the regal and the lumina and make them match. It shouldn't be too difficult but you may need to add a few wires.

 

 

But without looking at wiring diagrams you'll never know what is "easiest" to do.

 

Also you may need to use the 93 cradle. I'm not sure if the regal would have the rear lower engine mount needed for the lq1.

 

 

 

 

Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

Well, you have the entire parts car. It should be pretty easy..

 

a 2.8 car's cradle won't have the provision for rear transmission mount on the LQ1, so you'll need to use your entire cradle from the Lumina.

 

ECM does NOT change over, so use the Lumina one. No, swapping the memcal over won't work either.

 

I'd have to pull wiring diagrams for the C100, but I can't imagine it will be very different, if at all.

 

Radiator may or may not be workable depending if you have a 3 or 4 speed automatic now. Though a 93' Z34 radiator is thicker, at least if its the original one. the 93' z34 will have an external trans cooler, change that over, it just bolts on. easy swap. So basically if you have it, change it over.

 

AC you may have to swap the manifold line set over to accommodate the 3.4, actually there is another line you'll need to swap over too to make the pressure switch work right on the 93' harness. Its a little elbow pipe that goes from behind the accumulator area to the condenser. Now would be a good time to change to 134a, Actually get that pipe I just described out of a 94+ car. In doing that you'll gain a proper R134A high side fitting. One other word of advise is where it attaches to the accumulator it has a tenancy to galvanic corrode really bad making it impossible to separate without breaking. So might want to plan on having to get a new ac condenser.

  • Like 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...