So I recently did some stuff to the jeep, new water pump thermostat and radiator, ac delete bracket from an 87, I moved the vacuum canister and some stereo wiring as well.

A couple startups after this my rpms at idle were jumping up and down rythmically between ~200 and 1500. this went away and hasn't come back.

So I decided to go wheeling the other day and test out the new cooling system. At every hard bump the rpm's dropped off to nothing like the fuel pump just stopped working.

I've gone over all the vacuum lines and I don't think any wires are arcing. I'm at a loss any ideas?

 

Have you checked the fuel pressure?