Hesitation with an idling problem.

[Bayoubob45]

93 Explorer Eddie Bauer, 270K+ miles, original engine/tranny, original owner. Hesitates, runs a bit rough at idle and hesitates starting from dead stop, seems worse on warm, humid days better on cold dry days. Left idling for a while, check engine light comes on, but upon moving and getting to highway speeds, light goes off. Maintenance status: Recently had new plug wires (was told mine were old and breaking down), MAF replaced, general tune up including injector cleaning. Problem still persists. The "Apocolytic" converter is original equipment, do not appear to have any obvious exhaust system obstruction, but have not checked back pressure. Not certain if throttle body was cleaned. At highway speeds runs smoothly, gas mileage is about the same it has always been. Could dirty throttle body alone be the problem, assuming all other work was done properly ?

 

[1st explorer]

ever have the upper and lower intake gaskets replaced?if i'm not mistakin you should spray some throttle body cleaner in the valley of the intake.try to hit the intake openings.does the idle change.maybe someone can elaborate on a better testing meathod,good luck ,mike

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 91-94 section. Clean the mass air flow sensor, and find out what the code numbers are.

 

[Reejerey]

even if the light isn't actively on it should still read the codes for you. Find out what those are. It sounds like an airflow issue, either a vac leak or unmetered air (air after the maf). I've seen both cause hesitation and idle issues.

 

[Bayoubob45]

ever have the upper and lower intake gaskets replaced?if i'm not mistakin you should spray some throttle body cleaner in the valley of the intake.try to hit the intake openings.does the idle change.maybe someone can elaborate on a better testing meathod,good luck ,mike

Thanks for the hints...will give it a shot as soon as I get some time after the holidays.