My 2.8 V6 blew about a week ago and I dont have the $17,000 for the 632 CID 925hp crate motor I want so I had to go to my local "salvage yard". I went through all kinds of crap with them wanting to sell me a 2.8 out of an S-10 and I would have had to make all kinds of changes. They were gonna give it to me for $300, but I wanted a pretty much "bolt-in" motor. I ended up taking a 3.1 out of a 1990 Firebird - talk about direct bolt-in. Now I totally forgot to ask about the computer and someone asked me about it. Anyone know if I need a whole new computer? Or can I just get the chip? And if I run it with the old computer, what kind of trouble will i run into? I'm willing to throw in about another $100, so if anyone has any ideas, I'd appreciate it. Thanks!

 

Hmm, your '89 is a MAF setup and the '90 is a SD (map) setup. The best way to go would be to get the computor and harness from the '90 and swap them into your '89. The computer is different between them. This way is also the most work. Also eliminates the expensive MAF which sooner or later will go bad.

There is no 3.1L chip available for the '89 computer as no MAF 3.1l f-body's were made. Being that the '89 is a MAF setup it may run well enough as is.

HTH

RBob.

And enjoy the new found power. . .

 

Yeah, don't even bother with any computer swap. Leave your car's electronics alone, bolt everything old to the 3.1 motor... injectors, sensors, etc. If the 2.8 computer/chip/injection can figure out an upgrade to a 3.4, it can handle an upgrade to a 3.1 motor.

 

Well you coulld pull the harness and computer for a 1990 3.1 F-body annd go through the hassle of changing harnesses but that's a major PITA. Do you still have your blown motor? If so, remove it from the car and set it next to the 3.1. Find all of the differences. Take any parts that are different off of the 2.8 and attach them to the 3.1. End result is the 3.1 will look exactly like your dead 2.8. Install the 3.1 in the car and use the original harness and computer. Check the tech articles on the main page as KED85's 2.8-3.4 swap boogie will help you in this endeavor -- even though you are not going to a 3.4 (2.8,3.1,3.4 are the same blocks)

 

This might be a good time for porting/polishing...

 

Well the 3.4 has a bigger bore and if you want to use the 3.1/3.4 crank in a 2.8 you have to use 3.1 engines pistons do to valve clearence. The 3.4 has different heads and bore so you can't mix up pistons there. Rods are all the same.