Hi All
I Have A 93 Ranger 4.0 It Runs fine Except On Idle.Ive cleaned The Iac Valve Out But Its Not Made Any Difference.Can The Pcv Valve Cause Rough Ideling,They Used To Cause Problems On The Old Escorts As I Remember,Ive Cleaned It But Thats Not Helped Either,Any Ideas Before We Get To Changing Inlet Manifold Gasket,Oh Ive Checked All The Vac Pipes For Splits Or Leaks But Ive Found Nothing.

 

clean the MAF and welcome to RF

 

yep, what mossy said, i just cleaned mine last night and its alot smoother, at least in my head it is lol.

 

Thanx Never Thought Of That ,Anything In particular I Should Use,Would carb Claener Be Ok??

 

get some electrical cleaner or MAF cleaner

 

a & a you got a pm, just follow them instructions

 

Thanx A Lot Kevin,Soon As I Get Rid Of This Crappy Discovery Out My Garage Door ,Ill Get Ranger In And Clean Maf.Will Let You Know How I Get On.

 

Well I ve Cleaned Out The Sensor And Id Be Lieing If I Said It Wasnt Better,But Its Just Not Quite Right.If You Watch The Rev Counter It Seems To Surge up and Down Slightly.Ill Run It A Few Days To See If It Gets Any Better Maybee Ecu Needs To Adapt To A Clean Sensor.Will Keep U Posted.

 

if you pull your number 5 spark plug out and it looks fuzzy or coated in oil you may have a loose intake manifold. if you go to the tech page on that link i sent ya in the pm it goes into detail.

 

Cheers Kev Ill Have a Look At That.

 

My 97 4.0 ohv was doing the same thing and it took me forever to realise what it was. Check ur plenum gasket. Mine was loose and causing a surge at idle. take carb cleaner and spray around the bottem of the plenum. if it revs up u have found ur problem. hopefuly this saves u some headach. and that gasket is easy and quick to change