Okay update I checked the vaccum while running again and the needle still bounces but not nearly as bad and still drops low when throttle opened when snapped shut it did as described. How ever I did test the crank sensor and found that it had resistance in range but didn't generate a voltage when cranked (test on DC and AC setting) and nothing I followed video of mat from bleepinjeep

 

Sucess everyone replaced the crankshaft sensor and re hooked up the exhaust I got a B.A. running little rig thanks everyone for your time and help. You guy are awesome

 

I knew it wasn't the dizzy pickup.........

 

Just to be clear. It would start and idle fine, but not rev up. Then the CPS on the bell-housing was changed and that solved it? Just want to be clear!

 

Yup.

 

A funny side story. Years ago Cruiser asked me, "go out and unplug the wires to your distributor, and come back and tell me how it runs". So assuming this obviously intelligent man was maybe a quadriplegic, or wheelchair bound, or maybe in prison somewhere, I dutifully ran out there, unplugged my cam sensor, and reported back. (so he would know), "About the same, maybe a little slower to start sometimes".

 

Just a FYI for anyone who thinks their cat may be clogged. Just unbolt the exhaust from your manifold a little bit. I mean just a tiny bit. Just opening it up 1/8" will tell you if the cat's clogged or not.

Open it up 1/8" or more, go drive it. You'll know immediately if that is the problem or not.

You don't even have to disconnect it all the way.

 

I tried unbolting first I really did but the heads on the ones to word the middle were so stripped and after you punch the bottom of your jeep enough times yo kinda just say screw it lol. Beside the old good parts of the exhaust is the header and cat and muffle everything else is rusted through

 

Ohh another quick question, this jeep is my first 4x4 and I have always been told take it out of 4 wheel before getting on dry pavement, I do but why?

 

Any difference in rotations between the fronts and rears can add up and put a bind between front and back. You want to be on gravel or snow or something, so when something gives, it's your tire sliding a tad on the surface.