I am not sure which PCM to use, the one that came out of the 3800 donor car or the original ECU that came with my 2.8. I would think the OBD2 PCM is better due to the tuning and diagnostic capabilities. Can you guys tell me what you used in your swap and if you would've went with the other choice instead? Thanks guys, love this forum!!!

A stock 2.8 ECM not only sucks balls but also won't work for a 3800

OBD-II !! you would never get it running right with the 2.8 ECM ! And i you use the 3800's auto trans you need the PCM to control it.

Where would you put the distributor?

Im sorry, I'm confused...what distributor? The 3800 series II has a coil pack....

Exactly, the 2.8 ECM is for a distributor, so it wouldnt work.

[This message has been edited by Mike Gonzalez (edited 02-17-2011).]

oh ok, I got confused because I saw the GMTuners page that showed all the connections to the C500 and I think the C201 or something so I assumed that was how to re-wire the 3800 harness for use with the 2.8 ECM. But now that I think about it that wouldn't make sense as the fuel maps, timing and virtually everything else wouldn't work for the 3800. Duh! Sorry to waste your guy's time.

Not being rude but you really need to do some research and lots of reading if you are starting with this question.

np - it's cool. I at least got a good chuckle out of it. I was trying to think of how perhaps you could do some toothed belt off of the crank to run the distributor.

Yep the charts on gmtuners.com are to re-pin the connectors and harness to make the 3800 PCM pretty much 'plug into' the Fiero body harness. Again that is totally re-wiring the engine harness so it basically plugs into the body harness.

C203 and C500 are the two body harness connectors that the engine harness plugs into.

Like I said also the Fiero ECM is a POS. An early generation of port injection. It runs very slow. That causes some issues. The 3800 PCM is much much better.

[This message has been edited by phonedawgz (edited 02-17-2011).]

Rotrex, I take no offense to your comment but the way I see it is if everyone just searched all the time and never posted new threads then this would be a dying forum. Plus, this is a good way to find out new information and not outdated info from years ago . Also, its a good way to make new friends and meet people. It takes more effort to write negative stuff on here than its worth. Thanks for the reply though.

98 or newer PCM. Even if the engine is older.

The stock Fiero 2.8 ECM cannot be used with the 3800 - period.

If you've got a 3800 Series 1 engine, you would be best off using a PCM that came stock with that engine (all are OBD1). You could probably tune an OBD2 PCM to work with a Series 1 engine, but you're going to have a lot of tuning work to do to get it to run right.

All of the following are OBD2 PCMs...

If you've got a 3800 Series 2 engine (supercharged or non), and you are using a manual transmission, non-electronic auto transmission, or a 4T65-E that is older than 2003 model year, the best PCM to use would be a 1998-2000 model.

If you've got a 3800 Series 2 engine (supercharged or non), and you are using a 4T65-E transmission that was made in 2003 or later, you'll need to use a 2003 PCM.

If you've got a 3800 Series 2 Supercharged engine, and you are using a 4T60-E transmission, you'll need to use a 1996 PCM.

If you've got a 3800 Series 2 NON-supercharged engine, and you are using a 4T60-E transmission, you can use a 1996 or 1997 PCM.

You can use a 3800 Series 3 (supercharged or non) engine with a Series 2 PCM as long as you get an adapter plate and run a cable-op throttle body. If you are going to keep the fly-by-wire throttle body, then you MUST use a Series 3-specific PCM (2004-newer).

Hope this clears it up.

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

quote Yep the charts on gmtuners.com are to re-pin the connectors and harness to make the 3800 PCM pretty much 'plug into' the Fiero body harness. Again that is totally re-wiring less than 1/4 of the original engine harness so it basically plugs into the body harness.

Fixed

[This message has been edited by darkhorizon (edited 02-18-2011).]

hey Darth, if I use the original 4t65e-hd trans that came with the 3800 sc L67 (1998 Regal GS), can i just keep the 98's PCM or do I have to go with a 1996 PCM like you said? Thanks for the info.

Yes the 98 will work with the 4T65E, the 96 PCM is for the a supercharged engine with a 4T60E trans.

quote Originally posted by esco105: Im sorry, I'm confused...what distributor? The 3800 series II has a coil pack....

3 coils packs. 1 for 2 cyls.

Now does this mean that I could use any 3800 PCM, supercharged or not from '98 to '00 for my 1999 3800SC engine?

Cool. I'll be using the 98 PCM....can anyone recommend a person to flash the PCM for this swap? And what emissions should I take off since my state doesn't require tailpipe check for this year of car?

You could go to gmtuners.com to have it flashed.

If that doesn't work you could try Darth Fiero.

If he won't do it try Ryan.

quote Originally posted by esco105: Cool. I'll be using the 98 PCM....can anyone recommend a person to flash the PCM for this swap? And what emissions should I take off since my state doesn't require tailpipe check for this year of car?

It is not required you flash most 98 PCMs (if it came from a grand prix you are fine, others are hit and miss). You can take off all emmisions equipment as you see fit, but I probably would not delete them without some pcm adjustments.

quote Originally posted by phonedawgz: You could go to gmtuners.com to have it flashed. If that doesn't work you could try Darth Fiero. If he won't do it try Ryan.

All three are the same guy! (ME) LoL

-Ryan (aka: Darth Fiero) (owner: gmtuners.com / Sinister Performance, LLC.)

quote Originally posted by Darth Fiero: All three are the same guy! (ME) LoL -Ryan (aka: Darth Fiero) (owner: gmtuners.com / Sinister Performance, LLC.)

Awww - you ruined it Ryan - I was just playing a little with the noob.

quote Originally posted by phonedawgz: Awww - you ruined it Ryan - I was just playing a little with the noob.

I thought that was funny stuff! LOL