I have a 98 XJ 4.0(106k miles) that has just been tuned up about 2 months ago-plugs, wire, cap, rotor, etc. It also has a new ignition switch installed in January and a new battery installed last week. It doesn't want to start on first crank, but will always start on the second crank (or after a very long first crank) and this didn't start to happen until just after I installed the new battery. Otherwise it runs perfectly. No chugging or RPM loss.

I don't think its the starter cause it starts just fine, just not right away.

Also, I don't think it is a fuel injector or pump since it runs great.

I'm guessing it is throttle position sensor but not too sure?

Any ideas??

 

Anybody??