supercharged 91 , pcm tuning list

[J Wikoff]

If you look in my random parts for sale thread, I've got a 92 PCM for reference.

[tpulliam79]

well after looking closer , i dont think its a pcm I think its something else, the warning sticker on it says its got something to do with the lighting? I will snap a pic in a bit and post it. thanks for the reference it looks the same and has same number as the one in the thread. I am pretty sure i was mistaking something else as a pcm, its about half the size and says dignostic something on it.I'm digging through he fsm to see if i can figure out what it is

[J Wikoff]

Retained accessory control or something like that?

[tpulliam79]

probably something, it has a lot of wires going to it I will figure out what it is or get a pic. I have been looking at the pinouts for the 92 you supplied and am confused, it looks as if the all the spots are used and leaves none for the gauges and such, do the wires from the gauges not go directly to the pcm? Probably sounds like a dumb question but wiring confuses the heck out of me

[J Wikoff]

I haven't looked into the wiring. I guess it'll become clear when I get pics of those pages in the FSM.

[tpulliam79]

hopefully it will make sense

[tpulliam79]

ok so , do the wires from the gauge cluster get wired into the pcm or are they wired to somewhere else? I was thinking of just pulling the connector for the gauges and rewiring each pin, but i need to know where to wire them from. I am hoping to tackle the fuel pump this weekend, and getting the pcm burned in the next week or so. once I get the fuel pump in and vats deleted I should be able to start her up

[willwren]

Taylor, I'll do some digging this weekend for you. I doubt the general gauge wiring 'method' varied greatly from 91 to 93 or 95. A 91 FSM would be great though.

[tpulliam79]

Taylor, I'll do some digging this weekend for you. I doubt the general gauge wiring 'method' varied greatly from 91 to 93 or 95. A 91 FSM would be great though.

I have the 91 fsm and know what each of the wires coming from the gauge does but am confused on where they get wired to. From looking at the pinout for the pcm harness above I dont see where they could go. I think i have enough info to send my pcm out monday.

[willwren]

I wish I had that 91 FSM here in my hands!

[tpulliam79]

I wish I had that 91 FSM here in my hands!

I wish you had the fsm in your hands here I have looked through all the pinouts I can find for the pcm connectors and don't see anything about gauges. the wires from the gauges do go to the pcm right? am I not looking in the right place ( fsm is difficult to navigate). is there a module or something that controls the gauges or are they run individually to each sensor or does the pcm control them?

[willwren]

I'll dig in my manuals, and if nothing else, give you a better idea of where to look. Tomorrow morning over coffee.

[tpulliam79]

I'll dig in my manuals, and if nothing else, give you a better idea of where to look. Tomorrow morning over coffee.

you're the man

[willwren]

Always worth the time for my couch bitch.

[tpulliam79]

Always worth the time for my couch bitch.

why is it when i look at the wiring section in this fsm it all looks like swaheelie?

[J Wikoff]

I took pics just now, but I'll post them tomorrow. I'm off to bed.

One thing of interest I found...

"The PERFORMANCE shift pattern has higher engine RPM upshifts, and downshifts which occur at a lower percentage of throttle position than the NORMAL shift pattern. The PERFORMANCE shift pattern also offers increased engine torque output during second and third gear transmission operation."

[tpulliam79]

do some of the wires from the engine wiring harness hook directly up to the gauge cluster wires? if so it might make a little bit of sense to me.

[J Wikoff]

Actually, it looks like little actually comes from the PCM. Most seemed to come from the sensors themselves.


...ok, so I'm not in bed yet...

[tpulliam79]

Actually, it looks like little actually comes from the PCM. Most seemed to come from the sensors themselves.


...ok, so I'm not in bed yet...

it looks like there are only about 4 wires or so from the pcm connectors that arent hooked up

[willwren]

Ok, for the warning LAMPS (dummy lights) it looks as if they all go back to their respective systems. Turn signals and bright indicator for instance are powered by those lighting circuits. Traction and ABS lights come from the ABS system (EBCM). Much of that obviously doesn't need to be changed, so good news. The only stuff that is affected are those things only controlled by the PCM or coming from the different drivetrain.

Keep in mind this is from the 93 FSM (should be similar to the 91 in wiring/function method, but probably not wire colors and actual pinouts, but it is something to use as a possible guide):

Coolant temp gauge directly back to the sensor. I need to figure out which one of the two sensors on your 92 motor is for the gauge. IIRC, the one to the REAR of the manifold is for the gauge, and the one under the TB is for the PCM.

Speedometer from the PCM (VSS output pin). Connector C3, Pin D10 for 93, 92 should be the same. 93 is a dark green wire.

Fuel gauge back to your sender. Stock wiring, if intact, should be fine.

If you have a tach, it'll go back to the ICM. If you convert to a delco ICM and coils (keeping what should be on that 92 motor), it's the white wire. Probably is if you have Magnavox too.

Oil pressure gauge (if you have one) goes back to the sender. Otherwise, just dummy light wiring (back to the sensor). The oil pressure sender on the 92 motor will have two outputs. One for the gauge, one for the PCM (or in your case, that output would go to the dummy light/PCM)

Can you post a pic of your gauge cluster to narrow down the other things for us?