I am in the process of building an adapter to convert from 165 ECM to 7730. I have printed out the repinning table and I am stumped at what exactly I need to do about vss and vats wires. Which pins will I end up using and what needs to be done in the prom?

 

If you haven't already looked at this page, do so.

http://www.eecis.udel.edu/~davis/z28/

If you have and you still don't get it, I hear sending Michael an email with questions usually get answered.

 

I have already been there. That is where I got the repinning table. I just don't understand the part about the VSS and need to know what to do with VATS.

 

I don't know how to explain it any better. The only thing I think may be confusing you is that the vss wires go directly from the tranny to the ecm and not to the buffer. Of course, you will need to make a prom change for it. The VATS stuff is trivial. Uncheck the VATS box in the editor you are using and the system will be bypassed in the ecm.

Go search the diy-prom board with the keyword "vss". You'll find a few posts with questions like yours.

 

I switched over from 165 to 730 and the vats is no problem. In fact someone tried to steel the car the other day and they did not get it because of the vats. busted up my steering column good though. The way I understand it is there is a module that recievs the proper code/resistance from the key and sends a go or no go signal to the ecm. So as long as you have the original vats module and original key the computer should get the right signal and fire. I got a aftermarket VSS from jags that run and it works great.

Rich

 

What I didn't understand is that the repinning table showed pins BB9 VSS Low, BB10 VSS Hi, BB11 VSS output 4000ppm, and BC1 VSS output 2000 ppm. Do I just leave all of these open and connect BC6 on 7730 to A10 on 165 for buffered signal?
Sorry for the ignorance just can't understand why the 7730 has so many more VSS than the 165 in my 88.

 

No. the two computers use totally different vss signals. I had to get a aftermarket vss that sends the proper signal to the computer and drives my spedo cable. If interested I can look over all of my notes from my conversion. I know I left the orignal vss in the car and the wire is not hooked up and I ran two new wires from the new vss to the computer. I will have to dig out my notes to refresh my memory.

Rich

 

Thanks, I would like to see what ever info you can find but the other problem is I replaced the stock transmission with a turbo 400 and I will have to order an adapter to go from cable to electronic speed sensor.

 

The VSS I got screws into the tranny where the spedo cables goes and the spedo cable screws into it. Therefore it drives the spedo and sends 4000 pulse per mile signal to the ECM. there are two wires that come out of the VSS and I pined them into B9 and B10 of the computer. It is an AC signal so polarity does not matter. The other VSS signals you refered to are outputs and should not matter. The one at B11 goes to the spedo which in your case is cable driven so no connection in this situation. The other output at C1 goes to the cruse controll. Now I can not varify this because my cruse never worked and I have yet to fix it but with you old VSS still in place behind the spedo itself and still hooked up your cruse should get the 2000 pulse per mile sig it is looking for. So once again in your case no connection at C1. The only other part I had to change was the knock sensor. I bought a knock sensor for a 90 TPI. I pinned it into F9 by unpluging the ESC module and soldiering the white and black wires together. The white wire goes to the sensor and the black wire goes to the 7730 ECM. Also I took the plug for the old MAF sensor cut it off and used the wires to run the map to the ECM. This took some time and soldiering but it worked great. I can't go into detail on that now because my Girl friend has the car at work and my notes don't cover it so if you want to know how I did it I will look at the car. All said and done all of the sensors and wires either are or look like they are in the right place for a 90 to 92 and if you looked at my car now you would never know it used to be a MAF car.

Rich

 

My car does not have a speedometer cable. Only the VSS and two wires. The dash is digital, so does it get its readings from the ecm.

 

I am not sure there. I would say find out how the spedo gets its signal and what kind of signal it is. then try to match it. I do not think the signal comes from the 165 ECM. I don't recall the 165 having an VSS output so there is probally a secondary module that runs it. once you figure that out we should be able to come up with a solution. I know what the 730 ECM wants, now lets figure out what the spedo wants. Is this a camaro or a bird? What year?

Rich

 

I am converting an 88 corvette. Would there be any vehicle speed sensors at any of the wheels?

 

Corvettes I am not sure of but it should be in the transmission itself or in the spedo head with a buffer.

 

ok, one more question. Does anyone know how many times the vss (2k ppm or 4k ppm) pulses per revolution of the output shaft.

 

The 165 ECM receives 2000 PPM DC current and the 730 ECM gets 4000 PPM AC current.

 

I understand the 2000 pulses per mile and the 4000 pulses per mile but I am wondering how many pulses per revolution the vss makes. Does it just pulse one time per revolution of the output shaft or multiple times and how many? I am needing to know how many pulses per revolution so I can figure out which speedo gear to get.

 

Sorry I don't have the answer to that. As far as I am conserned 60 MPH is 60 MPH. If you have the right spedo gear for your rear gear and tire size then the VSS should fall into range. But I am not fluent in vettes so I could be way off.