Ok so Im installing my wideband and was looking for the AC input signal wire from the compressor but I cant find it!? I think when I had the wiring harness out and reworked for my thirdgen I had them delete some of the connections I wasnt going to use (AC, Smog etc) so my question is whats the pin number, connector color and wire color for the AC signal wire at the PCM? I need to find it so I tie in my output signal from the wideband to datalog my AFR. thanks!

The wiring harness and lt1 is from a 97 camaro.

 

Check the 95 wiring diagrams on Shoebox's Tech Pages.... not likely there are any significant differences in the A/C signals.

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_wiring

He also has the PCM pinouts, marked to show the differences for 96/97:

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_pinouts

 

Thanks great info!

 

will obd1 let you log an ac input? i dont remember it being an option or output in tunercats

 

You dont need it in TC, you just use it as a tool. the benifit of sending the output through the PCM is that you can data log it. datalogging it along with everything else lets you know exactly what you AFR is at the corresponding engine RPM/load.3

EDIT* the OBD1 pcm already has the input for the AC pressure, and as far as the PCM is concerened it thinks the wideband output is the AC pressure.

 

So this can be done with datamaster? I would definetly like more info on this. I am about to install a fast dual wideband.

 

DataMaster logs the A/C Temp and A/C Pressure.

 

Ya I cant tell you exactly how it works since I only have the wiring done, I havent actually logged it yet. What I have read and researched is that in the AC pressure clolumn it will for instance read 134 psi which means your at 13.4afr. finding the AC pressure wire was easy with the info on the Shoebox page. just make sure you use a good ground. my autometer wideband recomended using the block.

 

Thanks for the info, that will make tuning so much better.

 

So all you need is the Bosch wideband O2 sensor, and a bung? You weld in the sensor and run it directly to the AC pressure input?

I just want to confirm that all you need is the sensor and wire to get the signal to the AC pressure signal.

I have LT1 edit, and the ability to datalog with my OBDI conversion.

Dan

 

I would like more information on this as well. I will be installing a wideband sensor when I get my new engine in the car and have been looking into wideband options. The best I've found so far was the LC-1 plus, which is about $300. If I can use the OBD1 PCM without having to buy anything more than a wideband o2 and weld a new bung in my exhaust for it, that would save me a ton of money and time.

Also, would there be any interference with the A/C? I don't really want to delete the A/C or have any problems with it. Can you just disconnect the temp and pressure leads to the PCM and hook up the wideband in there place?

 

Anyone? I'm very interested in finding out an answer to this. Wideband O2s are a lot cheaper than the LC-1 plus package and I could use that money toward other parts for the Z.

 

You still have to have the wideband controller. It has the output signal needed. All this does is add your wideband reading to your data readings so you can have it along side all the other readings.

 

Does datamaster need any extra configuration to make it work?

 

What tap out said, you still need to buy a wideband setup like the lc-1 lm1 autometer etc... the O2 sensor is just a sensor you need the box that controls it ie heats it converts the data. what you need to look for in a wideband setup is that the controler has a 0-5v signal output. the signal output is what you connect to the ac pressure wire. I wish it was as easy as just wiring in the sensor

And no on the data master question. if you open datamaster, on the front PCM display you will see pretty much all you inputs (knock, tps%, IAC pos, MAP, etc.) you will see the A/C Press PSI output in the right column.