Car runs good, except under load. In 6th gear at 1500 rpm, if I lean on the gas to pass someone (not tromped), it feels like 2 cylinders cut out. Same thing happens in any gear at any speed. Also under full acceration it feels and sounds like the same thing, until I let off to about 80% throttle.

65K miles, wires were changed about 10K miles ago. MAF sensor had gotten gunked with the oil from the K&N filter, so I cleaned that out, although I'm told I shouldn't do that.

Also, Check Engine Light is not coming on. How can I check the codes on this model?

Any thoughts?

 

Check codes same as any other pre 1996 auto, short the 2 pins in the diagnostic connector together ( looking at connector, the 2 in the right upper row of the connector). Sounds like ignition problem to me, could be crossfire in distributor cap considering known history of Optispark caps or spark plugs. Be sure and check plug wire routing for any chaffing of cuts or burn spots where it might also be arcing to ground. [8D]

 

I thought I read somewhere that it was pin positions 4 and 12 that needed to be connected to read codes?

No arcing that I can see. I'm gonna have a guy put it on a scope in a few days. If I need the optispark, do I buy genuine GM or an aftermarket from Summit? Looks like half the price or better.