Strange Idle / Throttle issue

[jackdod]

I have a 2005 Ford Explorer xlt (White Edge Edition) with the 4.0 SOHC Engine it has 89,000 miles on it.
The issue I have is it is fine when idling and above 1,000 rpm onwards okay and drives fine but if you are travelling very slowly and
the revs are above idle and between 1,000 to maybe 1,100 rpm then there is a definite lumpiness / roughness.
No codes get thrown up even if you hold it at the rough spot when stationary which is a little awkward as wants to shoot over 1,000rpm.

I have carried out following below, not just to try to get rid of roughness only but as vehicle is 18 years old and Jap import I am going through it.
Especially when the parts even original from rock auto are so good even with delivery and tax to my country.

Work done.

new spark plug leads (motorcraft)
new spark plugs (double platinum)
new coil pack
new Evap purge canister solenoid valve (I though could feel it pulling through inlet manifold when shouldn't)
replaced purge canister pipe to inlet manifold as was crushing under vacuum due to age of pipe
removed throttle body and cleaned up, also sealed gasket behind throttle body as plastic looked a bit gappy
engine flush and oil / filter change
Auto box transmission filter / fluid change
coolant flush and change

I have a fuel filter yet to fit but doubt that is causing the lumpiness.

So anyone out there who possibly has any suggestions would be greatly appreciated.
thanks for taking time to read.
Cheers Darren

 

[Fix4Dirt]

I have a 2005 Ford Explorer xlt (White Edge Edition) with the 4.0 SOHC Engine it has 89,000 miles on it.
The issue I have is it is fine when idling and above 1,000 rpm onwards okay and drives fine but if you are travelling very slowly and
the revs are above idle and between 1,000 to maybe 1,100 rpm then there is a definite lumpiness / roughness.
No codes get thrown up even if you hold it at the rough spot when stationary which is a little awkward as wants to shoot over 1,000rpm.

I have carried out following below, not just to try to get rid of roughness only but as vehicle is 18 years old and Jap import I am going through it.
Especially when the parts even original from rock auto are so good even with delivery and tax to my country.

Work done.

new spark plug leads (motorcraft)
new spark plugs (double platinum)
new coil pack
new Evap purge canister solenoid valve (I though could feel it pulling through inlet manifold when shouldn't)
replaced purge canister pipe to inlet manifold as was crushing under vacuum due to age of pipe
removed throttle body and cleaned up, also sealed gasket behind throttle body as plastic looked a bit gappy
engine flush and oil / filter change
Auto box transmission filter / fluid change
coolant flush and change

I have a fuel filter yet to fit but doubt that is causing the lumpiness.

So anyone out there who possibly has any suggestions would be greatly appreciated.
thanks for taking time to read.
Cheers Darren

i wonder if its IAC? though then i assume you'd see it at idle too... hmmm... bump for someone to see it!

 

[jackdod]

i wonder if its IAC? though then i assume you'd see it at idle too... hmmm... bump for someone to see it!

Hi thanks for the reply, don't believe there is an IAC on mine as electronic throttle.
Also what do you mean bump for someone to see it.
Cheers Darren

 

[Fix4Dirt]

Hi thanks for the reply, don't believe there is an IAC on mine as electronic throttle.
Also what do you mean bump for someone to see it.
Cheers Darren

that's right they removed IAC at some point...........

it just bumps the thread up to the front so hopefully the right folks will see it, or if not it falls back ad less and less people see it