Hey everyone, I have been searching for info on this swap for a while and have found a lot of info but I'm still unsure of a few things.
Here's what I got:
1999 sunfire gt 2.4 LD9 with knock and rattle coming out of 3rd or 4th cylinder. This car is just for getting to work and back so I don't want to spend a lot of money on it. I have a 1999 sunfire se model with a 2200 OHV that runs great but the car couldn't pass a safety in a long shot.
I know I need the headers off the 2.4, but I'm not sure of they will bolt up to the 2200. I plan to drop the entire 2200 engine/ tranny into the gt. what I really need to know is if the ECU out of the 2200 will plug into the wiring harness of the GT, besides the engine sensors and what not, I'm sure I can rewire that myself. It's the whole idea of gutting the interior of the car that I don't like. Any info would be greatly appreciated. Thanks!

Swap anything that's different between the two cars.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs

Ok, sounds simple enough lol. Thx

Nothing on the 2.4 will swap to the 2.2... You'll need motor, trans, wiring, ecu, all accessories, all sensors, and radiator.

and our engines only have one Header.

Ok that's very helpful, is the instrument cluster part of the accessories that need to be switched or just engine accessories? Starting to think this is an expensive swap, I paid 1000$ for this car only 3 months ago. Haven't paid for itself yet do I really want to do this swap. If I can just switch the ECU under the dash and leave all lighting/ interior wiring in the car I will definitely tackle this project. Thanks mystic I'm not experienced with these, so much knowledge on this site!

Chris Bailey wrote:Ok that's very helpful, is the instrument cluster part of the accessories that need to be switched or just engine accessories? Starting to think this is an expensive swap, I paid 1000$ for this car only 3 months ago. Haven't paid for itself yet do I really want to do this swap. If I can just switch the ECU under the dash and leave all lighting/ interior wiring in the car I will definitely tackle this project. Thanks mystic I'm not experienced with these, so much knowledge on this site!

They are both 1999 cars, so you do not have to swap the clusters. The engine harness will need to be swapped, but it is not that big of a deal. You would also want to use the 2.2 PCM(ECU). It will plug up and everything. Keep your interior wiring. They are the same. You can also keep your body wiring for the lights as well.

That's exactly what I was hoping for, just read so much stuff on this I wasn't sure anymore. I will be doing this within the next few days and let u know how it turns out. I am gonna look into upgrading parts on the 2200 engine. I will check some other threads for this but if anybody wants to post their opinions on modding a used engine, please feel free. It has 125k miles on it.

Well....you can keep the 2.4 ECU and have it flashed to a 2.2 tune. Since Ryan and a few others have flashed the GM reflash on a 2.2 PCM. It should work the other way as well, BUT being a 99 you never know. I have flashed a GM reflash onto my 99 and it worked, but a lot of my gauges wouldn't work. I would guaranty it would work if you had a 00-02.

Engine harness is a must, but not sure if you need other "new" sensors since some are the same. I'm not completely familiar enough with a 2.2 to confirm how many are or aren't the same.

Even if the trans from a LD9 an LN2 are the same the cases/ bell housing are not. For instance the LD9 and LN2 both have 4T40E 4 speed automatics, but only the internals are the same. Nothing else is.





PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

Maybe I will try to get the ECU flashed, if there is any wire splicing involved in switching the ECU then I will try to avoid that. The transmission looks like it has the motor mounts and clutch linkage so it should bolt right in, My plan is to leave the motors and transmissioandrogen her and do a complete swap. Am I gonna run into issues doing this then?

A reminder I do have both cars sitting next to each other during this swap so I should have everything I need, I read if I switch the transmission the flywheel is not compatible.

the ECU you are looking for is located under the passenger fender well near the horn... i would avoid splicing wires all together... just swap over the complete engine wiring. None of the sensor locations are going to be completely close in location on the 2.2 as would be on the 2.4... big example, the intake mani is on the back side of the motor on the 2.2 but is on the front of the 2.4

Not too many people here have swapped from the 150 HP 2.4 engine to the 110 HP 2.2 engine. So there isn't as much info out there as would be several of the other engines that are swapable. Most people have to use forced induction (turbo) to get the 2.2 to be as fast as a stock 2.4, and the fuel economy is the same between the engines.

As for transmissions... you'll have to swap it over too... the bell housings are different between the engines...

what I would do is swap everything under the hood except for the brake system from the doner car to the other car...

Do yourself a serious favor and take pictures of the 2200 set up BEFORE you take it apart. Mounting locations, sensor locations, wire locations (where the harnesses run across the engine and engine bay), etc. You have everything you need if you have two complete cars. I don't know what kind of facilities you have, but if you have a lift, don't crack the engines apart from their transmissions. I've done this kind of thing a million times.

1.Unplug everything from the body, wiring, fuel, etc.
2.Leave as much wiring on the engine as possible
3.Take the 4 big bolts out of the engine cradle from the bottom (put it on jacks first, obviously
4.Drop the entire cradle out of the bottom and move it aside.
5.Do the same thing to the other car
6.Put the 2200 cradle in the GT.


"In Oldskool we trust"

the only thing you will hav to go in the car for is the throttle cable other then that if your taking apart the interior your doin something wrong

as for the cradle in the last post that could be easy to do and could be hard those bolts sometimes are so rusted its not worth the hassel i would avoid goin that route if you have to dropping engines in the top are easy i did my 3800 with trans in the top



JBO since July 30, 2001

I ripped the whole interior out looking for the ECU, then I googled it lol. Pain in my ass but I got the motor and wiring harness out yesterday and I am going to work on swapping everything out during the week. I left the brake system and clutch line cause they are the same on both cars. The plugs are a little different coming from interior to engine harness because my car had a/c and this motor didn't but they should work. I have cleaned up a lot of parts for the 2.2 and it's looking good, only trouble I had was with the axle joints, I broke the seals to get them off but they look the same on both cars so not worried. Will post pics when done son, thx for all the tips much appreciated everyone.

It was not hard to lift the motor and trans out of the top of the car, just removed the hood, wiring harness and engine brackets and it came out no problem.

Ok so the car won't start, won't turn over or anything after switching the engine wiring harness and ECU from the 2.2 to the 2.4 body. Not sure whats going on any ideas?

do you see the theftlock light?

You need to do the theft relearn, since the ECM is hooked to a different cluster now, but it sounds like you have another problem, because without the theft relearn, the engine should still be able to turn over. I would check all fuses, and then check all the wiring to your starter. Trace back everything. You should have a relay in between the starter solenoid and the C100. Also, as basic as this sounds, make sure you have the engine grounded.

As far as I know, there is nothing different at the C100 connector pinout between the 2.2 and 2.4 vehicles of the same year, but with GM, you never know.




Edited 1 time(s). Last edited Thursday, June 28, 2012 5:24 AM

Engine is grounded and the starter is hooked up properly but isnt getting any power when ignition is on. Battery has 11.8 volts and the crank position sensor has no voltage when ignition is on. I have checked all fuses and wiring connections. How do I go about a theft relearn?

Does it crank...if not keep checking wiring and relays.




PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

It doesn't crank, I havent bleeded the clutch yet I am gonna try that and check wiring

Ad mystic, The theft lock light is on constant, not flashing. So is the check engine light.

So if I bypass the ignition and put a wire from the starter selenoid to the battery it starts and runs for 3 seconds and the anti theft blinks and the car dies. The light stays on after it does but does not flash. There is 2 amps going to the red wire for the crank sensor I don't know what else I can check..

OK, so you obviously need to figure out why the ignition cylinder is not getting power to the starter. Could be the relay, could be a bad wire.

After you figure that out, you simply have to do a theft relearn. This is why it runs for 3 seconds then shuts off. The procedure is in the FAQ library, IIRC.

Thanks for all the info! Theft relearn worked car is running great except the alternator isn't putting out any voltage, I had it checked at a parts store and it was all good, so I put it back in with a direct ground to the engine and it worked for a day and quit. I tried connecting it directly to the negative on the battery and still nothing. It is recieveing the exciting current to the windings I don't know what else to do. I have two brand new batteries and have checked all fuses. Please help I miss my car. Thx