Tire_rips

okay so I just got this GC yesterday. I posted a thread but for lack of a better title I believe it may not help me very well so here it is again with a better title to lure u in.
It's a 1994 Grand cherokee limited with 5.2 V8 and quadra trac. it's got 235,000 miles on the clock.

It won't idle. I have to keep my foot on the gas ever so lightly to keep it alive. When it's rolling down the high way it seems okay but if coasting to lightly the rpm will surge. It's also running super rich. You can smell it, it throws black smoke under heavier acceleration, it's getting about 2-4mpg right now.

Today with the helpfull advice and info from ol blue here on the forum I've checked and tested the TPs according to the repair manual specs and it's fine.
I have also checked the PCV and the hose and it's good.
I have also inspected all the vacuum lines and sprayed around with some wd40 to look for leaks.

I have not checked the EGR yet. The spark plugs are fouled out from running so rich. But I don't know if they're old or if they're fouled as a direct result of the current problem. Needless to say those are getting replaced tomorrow.
Also the plug wires are original mopar so I don't know if they've ever been changed or not but I'm going to replace them for reliability.


Thanks in advance for any and all help.
Cheers.

Tire_rips

Okay so I just changed the spark plugs.
All 8 of them. One at a time.
I parked the truck and got to work.
When I was done, just a few minutes ago, the truck will not turn on now.
The battery has a full charged, I just checked.
When I turn the key, the starter does nothing.
All electronics in the vehicle work.
When I turn the key to start it everything is as normal where the accessories cut out but the voltage does not drop.
The starter is not stuck.
Nothing is happening as if though the gear selector is in gear still. Ever do that? Well that's how it's acting.
All I did was change the plugs. What the hell happened?!?!?