is there any way to scan a 93 z28 other than counting check engine blinks?
i got a bad missfire right off idle once the car has been driven in city traffic for ten miles and needle in temp gauge is right in the middle when it start to miss real bad off idle threw outrpm range and does it some times after 2600 rpms?

 

Many of the new OBDII diagnostic tools have provisions for OBDI, or the ALDL port (as ours is called). I have one made my actron, it has detachable leads for ANY make or model, and can even read real time data on an OBDI system, freeze it and replay it. My second job is at Autozone, and if you sweet talk the manager you might be able to score one of their higher end units for a few minutes, they have them there, just arnt supposed to use em.

Charlie

 

Run it in open loop all the time, try unplugging the the MAP(or others) to get it to run off factory settings (no sensor input), only if you are in a stranded kind of situation.

 

maybe i can talk my boss into letting me use the snap it off one at work since i do all trouble shooting everyone else f-s up lol

 

TTS makes a version of DataMaster for the 93's.

 

Any OBD-I scanner with 12 pin cable should work on your car.

 

thank u box im so used to my obd 2 type data scan software that i was unsure if anything was avilable for the 93's i kinda wanna see whats going on before i do the H/C/intake swap

 

A typical off idle stumble is caused by the EGR. Easiest way to find out is pull of the vac line off the EGR valve and plug it then try it under the same condition.

While the idea above of forcing it into open loop is a great one. The method described won't do it. The only way to force it into open loop is to unplug at least one of the O2's. No other sensor will force it to open loop.

If the EGR test doesn't produce the right results, then forcing it to open loop can tell you if you have a closed loop control problem. Which will show up after the engine is warmed up.