I have an 87 5.0 TPI that is mostly stock except for the removal of some of the pollution goodies. I recently pulled the engine and transmission and went through both. While they were out I repainted the engine compartment and cleaned up some cosmetic issues under the hood. I now have everything back together and took the car for a test drive this past weekend. Seemed to have good power but the engine seemed to have a delayed response and the SES light came on.

I picked up a scanner from a buddy and found I had error code 33. After doing some research on this site I found that I had the MAF relay and the fuel pump relay switched. Switched the wires and started up the vehicle and the idle settled right in (it was faster before) and no SES light.

Now is where the gremlins come in. Since I had the scanner, I thought I would do some checks. When I connected the scanner back up it will not communicate with the ECM. I can not check for error codes or get any info. When I plug the scanner in I get the SES light to flash on. Same goes for plugging power into the cigarette lighter. The scanner I am using is an older snap on unit if that makes a difference.

Any advice to get the scanner working again would be appreciated.

Thanks

 

a commonly reported problem with the 7165 ECM is that they are hit or miss when connecting a scan tool . you may have better results using a lap top and "winaldl" or "tuner pro".

 

Thanks for the advice. I was thinking about getting set up to use my laptop but was not sure if I would have any better luck that way. One more question about the tuning softwares. Can I make any changes to set points with the laptop or is it diagnostic only.

 

that I don't know at present. BUT you will know whats going on with it in real time.

 

https://www.thirdgen.org/forums/tpi/...-pls-help.html