Computer Diagnostics 1991

[RJB44]

I need to diagnose a misfire on 1991 GMC Jimmy, but was recently told that my truck is to old to put on an electronic diagnostic machine?? I'm not sure I agree with that.

Feedback welcomed.

 

[Mav2u]

Your truck is OBD I vehicle. Not much stuff shows up on the diag tool when plugged in.

Timing is done manually on that year of truck.

 

[4X4HIGH]

Your truck is OBD I vehicle. Not much stuff shows up on the diag tool when plugged in.

Timing is done manually on that year of truck.

BASE timing is set manually but still computer controlled.

To the OP the OBDI system won't show you a misfire like the OBDII systems will.

 

[Jessie James]

Check the TBI section of the forums. You can pull the engine fault codes by jumping the OBD port with a paperclip, directions are in that forum somewhere.