So I just bought this truck, 95 jimmy nad it has been running great... Then today I ran a 4G cable for power to an amp in the back and after starting it up I now have a miss, or something and my CEL is flashing. I ran the 4G cable through the grommet in the passenger side floorboard, and under the carpeting to the back. pulled out the radio and plugged in the RCA cables and remote turn on wire, ran then down through the dash and under the center console then to the back.

I really dont think that I could have done anything to the truck doing that. I looked up how to pull codes and it seems I need a scanner, but the local parts places cant scan anything earlier than 96. Mines a 95... yay me... I read that I can jumper pin 1 and 2, but there are no connections inside either those pin spots.

I have a GMC Dealer about 15 miles from me, but I dont really want to drive it that far, and towing is out right now... Kinda waiting for a paycheck....

This sucks... any one have any ideas as to how i can check codes? If I can get the code I will have a start as to what to look for going wrong...

 

95 was a transition year between OBDI and OBDII. Flashing CEL is usually multiple misfire. You will need to find someone with a scanner capable of reading what they call OBD1.5

Does it flash right away, only under load, etc?

 

under load. first start up it is just steady, and idle dont feel bad. Oonce I start going down the road it feels like it is missing and running rough and the CEL starts flashing. Just read a bunch of other posts pertaining to OBD1, OBD1.5 and OBD2... My ECU is under the hood and on the coolant overflow tank. leads me to think this thing is OBD2... but the door tag says build date of November 94...

 

I don't think running the audio wire had anything to do with it either.

When's the last time it had a tune up? Plugs/wires/cap/rotor?

 

just bought it saturday... 14x,xxx miles. ran perfect this morning, unplugged batt and ran wire, then this started...

 

Maybe go back through and retrace everything you touched. I suppose it is possible you knocked a spark plug wire loose or something along those lines.

 

Yea, I did. the coil wire was backed off about 1/16th inch, re seated that, but that didnt change anything. I have new plugs for it, just standard autolite coppers. I will go out and get new wires tonight and fight to get them all put in tomorrow... Not looking forward to fighting #3 in the cold tomorrow... I am also going to lie to the parts store guy and say its a 97 so he will try to scan it. from everything I read I am pretty sure I have OBD2.

 

Go ac delco with all your tune up parts or you're just gunna end up in the same boat. There's a reason why so many people use them.

 

As mentioned, if the SES light is blinking, it's indicating a misfire. Start with AC Delco plugs, distributor cap & rotor, and good quality wires.

Early production '95 S&T body used OBDI. With a build date of November '94, (mid production '95 vehicle) and the PCM mounted on the right inner fender, I can just about guarantee it's OBD 1.5 and the standard OBDII scan tools will not communicate with it. There were very few late production '95 S&T body vehicles that were equipped with OBDII. GM did not produce the Oldsmobile Bravada in '95 partially due to the OBD inconsistencies.

 

My ecm is located on the coolent overflow tank, and mine has OBDII. They are out there, just ask your local parts store if they can try to read it.