burntorange

i have a 97 Camaro lt1 6spd about a week ago the car got a stumble in it but would ony stumble once or so and run fine the Monday as I was leaving work it dies at stop sign cranked few times fires up and runs great. well next morning same thing dies and fires up runs fine now the car has got hard to start smells flooded and tach jumps around bad, tried to scan and scan tool wont connect to car any ideas? im not a chevy guy so im lost any help would be great.

Injuneer

If an OBD-2 scan tool won't connect, check the fuse for the cigarette lighter - that's what supplies 12V power to the ALDL connector.

burntorange

fuses are all fine

Injuneer

What scan tool did you use?

burntorange

solus pro I put a icm on car it runs now but tach stil jumps around

Injuneer

Tach is driven off the PCM, based on the cam position signals from the Opti. If the high resolution pulse patter is going erratic, might cause the tach to jump around. The high res pulse signal won't set a code unless it totally disappears for 10 crank revolutions.

Might be worth checking the harness connector at the Opti, for corrosion or a bent pin.

I'd try another scanner. There are $25 cheapies that will pull the codes. If that shows no connection, the wiring for the ALDL connector needs to be checked. Did you verify you have 12V on pin 16?

burntorange

its powering scanner just wont read or comm. with car we tried cheap one as well