Help Mee!!!

[LiftedGmc355]

so i just did a motor swap in my 89 gmc i pulled out the stock tbi 305 and replaced it with a tbi 350 out of a 95 gmc. i never pulled the distributor out of the new motor and it was pulled out running just fine. i put the new motor in and swapped over all the wiring, knock sensor and throttle body from the 305 to the 350. the issue is that it sounds like its 180 degrees off timing. ive heard i need a new computer?? any help would be greatly apreciated. the truck is a base model 5 speed 4x4 if it makes any difference thanks

 

[Blue95]

THe computer is your issue, the computer still thinks it is running a 305 and now you have 350 injectors and a different engine.

 

[ChrisAU]

Did you swap in the ECM from the other truck? Or did you re-use yours? I'm not 100% positive, but I'd bet the ECM tuning is different between the 305 and 350.

 

[ChrisAU]

THe computer is your issue, the computer still thinks it is running a 305 and now you have 350 injectors and a different engine.

You beat me to it!

 

[Blue95]

haha, well he does not want the whole ecm from the 95 truck that would really make it bad, he needs a chip from a 5 speed/ 350 truck, not a 95 though, preferably from as close to 89 as possible.

 

[ChrisAU]

Ahh I didn't read about the year difference...yeah, but here's a twist, the '95 TB will have different injectors than the '89...

 

[LiftedGmc355]

thanks! but heres the deal my girlfriends dad is the commercial parts guy at advanced. we priced out a new ecm and there are two options, one is the same part number for both the 305 and the 350, and the other is different? so what do i do lol

 

[Blue95]

and more TM in the code of the computer, so I think to be for sure he needs a chip from a '92 5 speed/350 truck or older IMO

 

[Blue95]

thanks! but heres the deal my girlfriends dad is the commercial parts guy at advanced. we priced out a new ecm and there are two options, one is the same part number for both the 305 and the 350, and the other is different? so what do i do lol

I would confirm the right one at a dealer first then get the right one from advance, can you not look at any junkyards? maybe just get a stock chip from Brian at TBIChips.com?

 

[LiftedGmc355]

there is a pre 92 chevy at a local junkyard factory 5.7 5 speed i can get for 50 bucks but i can buy a brand new one for 74.00, ill check that website out right now