1996 Grand Prix 3100 (curiousity)

[3100 MPFI]

"Most people say that Curiousity killed the cat. I personally say that curiousity never killed anything except maybe a couple of hours!"

I started the OBD2 swap in my 1988 Cutlass Supreme. I am basically putting it to completely stock 1996 3100SFI (Vin J LG 8 )/4T60-E. I have a donor car (the pink car..... May it rest in pieces), so the wiring is not my issue.

I was going through some of the wiring to see what the main differences were, and I found some things that I am EXTREMLY curious about.

First of all, the OIL PRESSURE SENSOR only has one wire. Now my 1988 Cutlass Supreme was originally like that, but when I updated it, and then later when I did the original 3100MPFI, I had to put in the 3 wire sensor. The combined oil pressure sender, and fuel pump relay thingie.

The 1996 wiring only has the 1 wire. Not 3. What is up with that? I will get a pic of it tomorrow.


Also, it has that DOUBLE CANISTER PURGE thing. I did get a pic of it. What is it for, and why?






Lastly, the pink car seemed to be prewired for the VARIABLE ASSIST power steering. There was a red connector on the back of the engine near the EVAP stuff, but it was not plugged in. The terminals have turned green, and shit.

Is there a way to put that in without adding the ABS? Not that I am going to attempt it. Adding ABS to a 1988 car is close to impossible. Besides, the rear hubs were bad in the pink car and I can't afford new ones at this time.

I just know that it is controlled by the EBCM (I don't have the proper EBCM anyways. The pink car did not have the EVO, but my green 1995 Cutlass Surpeme does.

That is about it for now.

[Rhedalert]

Yes the oil sensor is 1-wire, it was also this way with my original '95 setup.

I don't know why GM changed the EVAP system, something to do with OBD2 diagnostics, but you have the parts and the computer so just use it. You'll throw a code if you use the older style EVAP solenoid setup.

My '95 has the wire hanging for the variable assist too. So in essence it's pre-wired thru the engine harness.

[3100 MPFI]

more curious if the variable assist can be used without the ABS working. Like, put in the rack, and pump, plug it in, and plug in the EBCM, but it not throw an ABS code. Then again, I could always add ABS, but I don't think I want to do THAT MUCH work.

[Rhedalert]

what does the ABS have to do with the variable assist? They share the ABS computer?

I never looked into it because I always thought that type of variable assist (where it alters the p/s pump output) is pointless. Just put in the FE3 rack that GM abandoned and call it a day.

[3100 MPFI]

I am just Curious about it, and I do have an FE3 rack to put in. In fact, I have the one that either YOU, or LORENZO gave me. It will be going in while I have the engine out of the car.

The variable assist is controlled by the ABS computer. Not 100% sure on the workings, but when I was looking for it as an upgrade to the pink car, I discovered that there were 2 listings for the EBCM. One with it, and one without it.

I was really asking more for a friend. He has a Cutlass Supreme convertible, and he already has the variable pump in his car (got it from a junkyard), but the previous owner REMOVED the ABS system when the pump went out. We were just curious if it could be added to his car without the ABS running working.

I will scan the wiring diagrams this evening to show you what I mean about its wiring.