i fixed my code 28 QDM by replacing the EVAP purge valve and cleaning the throttle body out.

i found out some interesting info today

the PCM is the same for a supercharged and N/A in 1992

i called the dealer and the said they are the same i just have to swap the Eprom chip

yup......IIRC the 58 VATS code is a bug in the 92'* isn't it?

i guess


well i changed the PCM

the Quad B fault went away

but i still had the Quad A Fault

so i disconnected the Vacuum line going to the BCS and Cleared the Code and it didnt come back
one problem now at full boost is Misses could that have something to do with the BCS not being hooked up
BTW tune-up was perfromed recently plugs wires
Could the miss be the Knock sensor pullin timing?

no other codes came out

you can hear a slient miss at idle i checked wires and they are all on

The bcs being unhooked could be causing many issues. Do you suspect the bcs as the failure?

KR won't be felt as a miss. It just retards timing to reduce pre-ignition/detonation.

Can you check the resistance of your BCS? Across the two pins? Should be about 30 ohms. If it'* bad, it'll read infinite (or very high).

Was your foot on the brake when you got the QDMA? Make sure it'* not next time.

i suspect the BCS at the problem im going to check the resistence in a bit