Hey there I have a 1991 camaro rs convertable. I have recently put a tune port 305 from a 1985 corvette or so that what im am told its from into my 1991 camaro wich was origional tbi. Now I have a wire harnesse under the hood from a 1988 and ecm aswell. Have swaped in a walbro fuel pump aswell as adjustable fuel pressure regulator also. Car will run great at idle all day but once u get out on the road she triggers the service engine soon light and has some hick ups along the way. My adal port dose not comunicate with my scanning tool? I have read few forms saying need to relocate the orange wire in adal port and I tried it last nite and no luck... anyhelp here would be greatly apappreciated. Im stumped at the moment. I know a and b in the port work as we had to reset the idle air controle motor on the throttle body and it did it like it should. Thats where I am stumped as to why my tool is not comunicateing with the car. Thanks

 

So your basically running an 88 MAF motor? Your using the 88 MAF TPI ECM and harness along with the complete 85 TPI motor and MAF sensor right? If so you bascially are running an 88 TPI MAF motor. Pin A8 should be the orange serial data wire that goes to the ALDL port on Pin M. Check the C100 connection under the passenger foot area and make sure the connection is correct there.

 

Have been messing with ideas here and I looked at few options here. At the ecm looks like tbi and tpi are the same. But where it connected to the dash tbi is two less wires than a tbi? Have been told that the dash should not make a diffrence. But why dose my adal port not function?