89 MJ hard start erratic tach

'89 MJ 2wd 2.5 tbi four on the floor.
So here's the issue I first noticed a missfire/sputter while driving the other day but only once or twice during a half hour of continuous driving. So I didn't think much of it, 'til yesterday when it did not want to start and when it finally did I got about 3/4 of a mile before it sputtered. So I turned around as soon as I could and as I was turning around it died. Got it started again and headed home. Got half way up the hill just before my house and it died again. So I rolled back down to a flat area and recalled reading about the issues that the grounds to the engine can cause on a renix. So I got to cleaning the grounds by the dipstick and the one from the firewall to the head. Got in it and it started but did not seem to be happy about it. But I made up the hill and into my driveway right when it died. So I left it be and hopped in the xj. So today I decide to mess with it again and hopped in it and it fired right up. Let it idle for a few moments and noticed the tach was jumping around alot. And when I gave it gas it didn't seem to be right with the rpms. So I was wondering if there was a common ground between anything on the engine and the tach?

I guess this is what I get for putting some decent speakers, full gauges, and a rear view mirror that I can see out of in it.

Might want to check your coil - sounds like it could be the problem and I think the tach runs off of it.

Edit: On an unrelated note, looking in your sig it says you have an F250 light bar on your XJ. Mind showing a picture of it?

a bad o2 sensor can make it act up too

Here's some pics of the lightbar. I got it off a buddy for like $50 with lights and just cut it down to the right width.

Yah I need to check all the sensors and get some specs but all my stuff is at work so I'll have to mess with some of that this week.
The coil looks pretty new unless4 its just clean because it's kinda covered up by some plastic.
Oh and brand new fuel filter ran some fuel system cleaner through it and the cap looks newer, but the plug wires are covered in oil (damn plastic valve cover) and I haven't looked at the plugs yet.