Could be many things.....Look and listen for any vaccuum leaks around the engine especially up around the fuel injection area. A vaccuum leak will have a high pitch whistling sound. With the engine sucking in extra air at a vaccuum leak this will pull down the engine and affect the RPM's. Run your hands along all of the vaccuum lines to see if you can find a leak. How long since you changed your spark plugs? Most likely it is the Idle Speed Control Valve located in the middle of the engine but on the top surface. If you take off this piece and spray it with Carberator Cleaner 3 to 4 times and let it sit for 15 minutes between sprays it will change things.
Yes.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
the crank position sensor can cause similar symptoms jeep is known for crank sensor problems
most common cause, a vacuum leak.
Just about all of the engine sensors could cause it to not run.
trash in your fuel filter
There are pages and pages of things that can cause a check engine light. Have the code checked with a scanner.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
A gasket could be the cause of a Jeep Cherokee engine to whistle when it's cold. Check the throttle body gasket to see if it needs to be replaced.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
If it was rebuilt wrong, Yes
Cause they lacked a written Language.