slow start and high idle(couple seconds) when cold

help new problem on 98 cherokee 4.0 when warmed up everything great

When you say slow start do you mean it turns over slowly or you have to crank for a long time for it to start?

good fast cranking just slow to fire.

Try cylce the key on then off a couple times then start the engine. Any differance? If so you have a possible stopped up fuel filter or a fuel pump starting to go. High idle? How high? It is normal to idle at about 1-1200 rpm when cold.

Are taking about when you first start it you it automatically revs up to like 1500 rpm for 2 seconds then drops down to a normal cold high idle. If so below will fix your problem.

Clean your throttle body really good. The best way is to go buy a throttle body gasket and take it off and clean it on a bench with a tooth brush & cleaner. Also remove the IAC (Idle Air Control) clean it really well it is probably sticking and gummed up. Also check and re-adjust the TPS sensor.
It is a very easy job.