Eddie Skaggs

Ok so I can run my jeep on interstate fine but when I’m stop light to stoplight it starts hard missing I’ve replaced injectiors spark plugs fan relay oil I don’t know what it is it’s a 2000 Jeep Grand Cherokee limited with a 4.0

dave1123

A LOT more information is needed. Year, model, engine, etc would help.

Eddie Skaggs

updated

97grand4.0

Maybe take it to a competent repair shop? Hows the fuel pressure? Sensors? Fuel pump? Do you have the infamous cracked head?

dave1123

You should do a cylinder leakdown test to see if you have a burnt valve or one that is carboned up enough to leak past it's seat at idle. The 4.0 is notorious for carbon buildup on the valves because of ingesting oil thru the CCV system. There are many ways of decarbonizing the valves, and the cheapest and easiest way is pouring a couple of glasses of water down the throttle body slowly when the engine is hot and running at 2500rpm or so.

Drewpyyy

my recently bought 96 4.0 would do the same thing but to the point it stalled at lights. replaced the map sensor ,idle air control as well as the throttle position sensor and it fixed it. don’t know which of those sensors is was but i figured while i had the intake off replace them all