Fatguy Posted June 1, 2013 Report Share Posted June 1, 2013 I bought a 95 Cutlass Supreme body and am paying a guy to put a motor in it. The motor he has is from a 3100 from a 1997 Grand Prix. He is telling me that it will drop in, but I think hat there will be some issues with the wiring and trans control. I want to convert this over to full OBD2 in the future, maybe best to do it upfront. My big concern is the transmission control. Who is right here? Thanks Quote Link to comment Share on other sites More sharing options...
Timm Posted June 1, 2013 Report Share Posted June 1, 2013 You're right, the transmission will be controlled electronically in the GP, also, you won't be able to use the wiring harness unless you want to move everything around under the hood. (Put the battery & fuse box on the pass side, and the PCM on the drivers side.) You'd also need to find a way to get that wiring harness to mate up with your main "C100" connector on the firewall up by the passenger side strut tower. You'd be much better off finding an OBDII (1996) 1st gen grand prix, or a 1996 or 1997 cutlass, also, the 1996 regal's will be OBDII, but I believe their transmissions are still vacuum controlled rather than electronically like the GP & cutty. Someone should be able to chime in and verify the last part, but I'm fairly confident you're correct in that the 97 GP won't be a "drop in" as far as wiring goes. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 1, 2013 Report Share Posted June 1, 2013 a 97 3100 W is still a 4T60E(99 was the final year). a 97 3100 engine in a 95.... should be mostly drop-in, as long as the engine harness from the 95 is retained/used. big differences are EGR(need an adapter, or use the 93-95 upper intake), knock sensor(need to use 93-95 sensor), coolant temp sensor(wiring change, possibly swap)... i think that's everything. as far as converting it to OBD2, you could almost use a 97ish 3100 lumina/monte carlo underhood harness without modifying anything at all. probably 97 3100 CS as well. Quote Link to comment Share on other sites More sharing options...
Fatguy Posted June 1, 2013 Author Report Share Posted June 1, 2013 Thank you guys for your input. I thought the GP body style change also included a change in trans. I have a line on a 97 Lumina chassis that I can remove the harness from (original plan). The shop has the original motor, so swapping the parts won't be that big of a deal. i am keeping the original motor to tear down with my kids so I will have him put the GP parts back on so I have them later. I need this running ASAP and will do the conversion later. I have searched for details on this conversion, and have not found a whole lot of information. If anyone can please provide links that would be great. Thank you again. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 1, 2013 Report Share Posted June 1, 2013 the 2G W 4T60E SHOULD be the same as the 1 and 1.5G W 4T60E.... they have the same broadcast code anyways. might need to swap a mount bracket, at most. trans connector should be the same, pinout should also be identical, but i could confirm that when i have a spare moment to look at the diagrams. 3x00swap.com would have had the guide to using a newer engine in an older system, but it's down currently. i'm sure the PDF still exists elsewhere on the web(60degreev6.com), but i don't have time to do an in-depth search ATM. Quote Link to comment Share on other sites More sharing options...
Fatguy Posted July 12, 2013 Author Report Share Posted July 12, 2013 (edited) OK, so I finally got my car back. I don't think I will ever have someone else do this for me again!!!! There are still a few unresolved issues, but it runs GREAT!!! I forgot how zippy these cars are. There was a major snafuu with the intake manifold. Does someone have a wire diagram of a '97 GP 3100 egr valve? I installed the correct throttle body tonight so I have my cruise control again. Also, where is the coolant temp sensor for the gages in the 97 3100's? The dash gage doesn't work and tonight I found the round single wire plug with a green wire right behind the canister purge solenoid. I removed as much as I could and didn't see a CTS in the head on the backside of the motor near spark plug 6. Other issues, the ABS light is on as well as the 'brake' light. The PO installed a remote start so I have to figure out what is up with the mess of wires under the dash and if the brake switch wire is correctly connected. At least when he pulled it out he wire nutted and taped the ends of the wires so I am not as concerned about shorts at this time. The mechanic told me that it looked like one of the abs wires was broken near the outer plug, but I have yet to verify to address the abs light. Pictures will follow. Thank You all for your help!!!! Corey Edited July 12, 2013 by Fatguy Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 12, 2013 Report Share Posted July 12, 2013 i can pull the EGR diagram tomorrow, but you're not planning on using that EGR setup on the 95 PCM are you? you WILL run into issues doing that. 97 3100 only had a single coolant temp sensor, certain vehicles got a 3 wire unit that does both the PCM and the guages, others got a single 2 wire that the PCM reads and then drives the guage from a PCM output. Quote Link to comment Share on other sites More sharing options...
Fatguy Posted July 27, 2013 Author Report Share Posted July 27, 2013 (edited) OK, tomorrow, I am going to get the necessary parts to convert my Cutlass. I am planning on grabbing the entire underhood harness as the JY here has a Lumina with the engine/trans removed. I have the O2 sens, knock sensor, coolant temp, injectors/harness, MAF and the EGR is already installed. Edited July 27, 2013 by Fatguy Quote Link to comment Share on other sites More sharing options...
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