Joe'sXJ

My 1990 xj is running rough. When it idles, the truck shakes a bit, not as a distraction, but im concerned. Also if i dont let it warm up for 2 mins when started it will die on me, and i have to restart it and then its fine. Sometimes however will reb to a high rpm... Do i need to change my TPS, or change out something eles?

Good Image if u need a diagram perhaps?

highmileage

there's a few sensors to check but for a start check all your vac lines for cracks mainly the one for the MAP sensor. also check and see if your CPS is covered in crud off the back of the engine. a weak signal from the CPS and a vac leak to the MAP can cause your symptoms.

Joe'sXJ

is a 90 to old to check for error codes?

Joe'sXJ

Also to add, when it starts up, u can smell a bit gas smell... Not a very strong scent, but enough to know its there, I replaced a piece at the back of the fuel rail that comes from the tank because it was cracked.

cruiser54

Yes. no code storage. You realize the photo you posted is of a different fuel injection system than you have if you have a 1990?

Let's start with a few basics. When is the last time the Jeep had plugs, wires, cap, rotor, and a thorough throttle body cleaning?

Have you ever done a good ground refreshing on your Jeep?

NYsNumba1Man

Could be the upstream o2 sensor. I had a very similar problem. Do you have an exhaust leak?

9hundred$ride

I had a leaking fuel injector that gave me the same problem. Took me two months to find it because I only take it out couple times a month. Wheeled it ppretty hard couple weeks ago. I put a set of 703 injectors and fuel filter and it fixed the problem.

LeRoy90laredo

x2, photo is for a 98, not a renix 90.
check for vacuum leaks.