[John Wood]

Yes, it can be a bear on these older cars. I think I had to wedge an offset box wrench in over the nut on my 87 or perhaps it was a deep well socket with a wobble or u-joint adapter. All of that goes away in later years when they started using a nut with a flat piece of steel welded on it (so it doesn't turn when you loosen/tighten the bolt). Soak the nuts with PB blaster, Kroil, Nuts Off or equivalent penetrent.

 

[John Wood]

well the symptions are stumbling and bucking while warmed up. When the engine is "cold" it is fine.. does not stumble much.. but after about 15 min of driving .. i feel like I am on a roller coaster with the bucking...gas millage has gone down considerably from 27mpg to like 13mpg. Switched the map sensor today just to see if it was that .. but the same with both of them. There is vaccum on the line..

I am really beginning to wonder if it is the computer. just to check I left the o2 sensor disconnected for 15 min while running it. There was no change in the way it ran but the computer never registered the code. I would assume it would by then.

By disconnecting the O2 sensor and running it for 15 minutes, you ran the car in what is called "open loop", meaning that the computer did not have full control of the fuel mixture. If the engine continued to buck, I'd guess that you have more of a fuel delivery problem such as a pump thats cutting out after it warms up, or a bad injector, or a clogged filter. I recall 1 post where a bad injector caused a similar problem. I'd try a used injector from a bone yard first if that is possible.

 

[John Wood]

Good information on the electrical issue. Thanks for the report and good job troubleshooting. That ground failure is a somewhat common issue as I've had to replace that ring lug on both of my EEKs, and I just re-crimped a new lug on after cutting off the old one off.