I know that this is an ignition related problem, but I'm having a bit of a problem trying to isolate it. I got this vehicle in Nov. of last year. As time and money permits I've been working on it to improve how it runs. Looks come later!
The vehicle now as 170K on it and is a '92 4.3 TBI Z. The thing had the ORIGINAL rotor and cap on the distrubutor, and the plugs wire were bundled together with zip ties! Fix that, and put new plug and wire in properly. Replaced the Fuel filter as this thing sat up a bit before I got it.
It runs way better now and for the most part will run so smooth that I forget how I ever stood it before I fixed it! BUT, every once and a while either during easy acceleration or even running on flat roadway with the cruise on, it will suddenly shudder violently in the front end! Man, that is aggravating. I know it's related to a crossfire event from plug wires I've seen when working in the shop years ago, but I've slept since then and have never encountered this type of problem until now. I've looked for places where the plug wires might be close to a ground source and such, but see nothing. Tonight, when it gets dark, I'll look to see if there is any arching going on there, but if that fails me, then I'll need some input as to another possible remedy.

Thanks, Wade

 

Might be a cracked or loose motor mount. They usually only do it under load, but you never know..Have someone sit in there, put it in gear, hold the brakes and give it a little gas, watch and see if one side of the motor raises up. It shouldn't.

 

ffox,

I feel like Homer Simpson saying "DDDDOOOOOOOHHH!!!!"

Of course, it makes sense. I got all fixated with the ignition issue and forgot all about the mounts!

Thanks buddy, ya got me back on track........

Wade