Ecotech to 3400 swap

Alerotgp · 03-12-2017, 08:23 PM

Ok, so I have an 02 alero 2.2 5speed that I swapped an 03 3400 into with a 5speed from a 91 z24 cavalier. I'm just about finished with the entire swap at this point. I just turned the key to make sure that the car would crank and I got nothing. I only replaced the pcm and engine wiring harness. I have read in a few posts about swapping from a 2.4 to 3400 that it might have been easier to swap the wiring for the whole car because of issues like this, headlights not working etc. the only issue I seem to be having is the no crank. I have also read that the bcm needs to be changed as well because the vins need to match. I did not change mine and the donor car is long gone. If this is my problem can my bcm be reprogrammed or do I need one from a same year 3400 car and would that need to be reprogrammed to match the vin? Could this whole problem be a pass lock issue? One other thing that I noticed is that there are no pins in the fuse block where the starter relay goes. The car ran without this with the 2.2, am I missing something? Any help would be greatly appreciated, thank you

3500Alero · 04-26-2017, 11:36 PM

Sounds like a couple issues. 1. You need to tune out the auto transmission on the pcm and possibly the theft system. 2. You may have to jump two of the wires on the harness that used to go to the shifter on the auto transmission (pcm is looking to see Park or neutral).

Redog · 05-01-2017, 08:21 PM

Do you have HPTuners? Because that is the main thing to get engine swap to work.

The PCM and BCM will need to have matching VINs or it will throw a code. I see you're a PA resident. This will be an issue at inspection time. Unless youre tight with the shop owner, they wont want to touch the car. The State Police to random check ups at garages and mine threw a red flag due to an incorrect VIN. I don't get emissions any more due to the car now being titled as a classic vehicle

Alerotgp · 06-01-2017, 10:33 PM

Thanks to everybody for the replies. Haven't been on in a while. I figured it out, I reset the theft system with no luck, but figured out I did have to splice the wires under the fuse block under the hood. As far as being a PA resident and getting the emissions done the Vin does not need to match the car. I did hold an emissions lisence up until a few years ago and it can still be run through but I forget what you need to do. I don't have HP tuners, I planned on sending the pcm out to have the auto transmission parameters disabled. I just got the car running about a week ago but now I have a new problem. I'm getting a very loud banging noise that seems to be coming from the bell housing. I'm afraid to leave the car running for too long to really pinpoint where the noise is coming from. The noise is not in time with the engine so it's not a rod knock and the engine ran fine when I pulled it from the donor car. Also I don't have the clutch hooked up yet, I think I'll need a custom line to get my master cylinder to work with the slave for that tranny. Could that have something to do with the noise I'm hearing? I will post this in another section as well. Thanks

Redog · 08-29-2017, 04:48 AM

Hmmmm, I'm not sure, but you mentioned the clutch.

My Alero is an automatic, but my Volvo is not. I had the clutch replaced in that and I heard the banging I think you are hearing. My mechanic did the job but broke a motor mount in the process and didn't notice it. He fixed it and towed the car on his dollar, so I can't complain.

5 speed Aleros are rare, so I hope my probelm helps. Mine was only when I would shift gears though, since the entire engine shifted in the bay