IT'S BACK!
You're right Flash, cleaning the MAF was a big deal, and the car runs a thousand times better now.
I did say I'd give it a week before declaring victory...
Friday on the way to work, I passed a truck on the highway, going up hill in 6th gear, and the shudder reappeared!
Strange, but once that happened, I could get it to repeat any time I pushed the accelerator down past 1/2 way when around 2K to 2.5K RPM. Just like before.
The shudder was there on the trip home from work also.
Describing the problem to a friend of mine who used to do engine control system design for GM led him to the theory that it might be an intermittent spark problem.
Would the computer pick this up and record a fault if it were the source of the problem?
I'm thinking that I just might need to learn to live with this problem, and take the car back up to Pete if it gets more consistent so he can witness it.
Ugh!
