Intermittent Rough Idle 96 2.3

[RF76]

120,000 miles
new plugs wires ect.
new air bypass valve
tb is clean
no loose vacuum lines

The truck runs great going down the road, no hesitation at all. When I take it out of gear and coast to a stop the idle is a bit high untill I completly stop then the idle sometimes will be very rough. I can give it some gas and it clears up, but then it happens again randomly? I don't get it.....

I have never replaced the tps, it's original, can a tps start to go bad or does it just quit? Just about every other sensor is new. Oh and no cel.

Starts fine, goes down the road fine it's just the random rough idle, any suggestions?

 

[modelageek]

120,000 miles
new plugs wires ect.
new air bypass valve
tb is clean
no loose vacuum lines

The truck runs great going down the road, no hesitation at all. When I take it out of gear and coast to a stop the idle is a bit high untill I completly stop then the idle sometimes will be very rough. I can give it some gas and it clears up, but then it happens again randomly? I don't get it.....

I have never replaced the tps, it's original, can a tps start to go bad or does it just quit? Just about every other sensor is new. Oh and no cel.

Starts fine, goes down the road fine it's just the random rough idle, any suggestions?

I am not sure if the tps could affect the idle but i imagine it could.......the water temperature sensor can go bad and feed the wrong info to the pcm causing and issue........make sure your coolant is topped off so the sensor is covered with coolant. I would also clean the maf..

 

[RF76]

I just did some searching here and found a thread where the owner had similar problems. All he did was replace the fuel filter and it stopped, weird, how could a clogged filter make the engine randomly idle rough?

Mine has about 70,000 miles on it. I'll change it asap and let you all know..

 

[ForOffRoadDriving]

+2 on cleaning the MAF.

 

[RF76]

Cleaned the maf, nothing different. Just bought the tool for the filter line so that's next.

 

[RF76]

Changed the fuel filter (pain in the ass & stupid design by Ford) still doing the same thing.

Any other ideas?

 

[RF76]

Sorry for the back to back posts.

I forgot to mention that the problem started immediately after I installed E3 Diamond fire plugs. Could this be the problem?

 

[modelageek]

yes

 

[RF76]

Based on what my friend?

 

[Cyrus2000]

just from doing my own searches and readings on this site, it seems most people do not recommend using anything other than motorcraft plugs and wires for these engines... also specifically, something about multi tip plugs = no bueno, if i recall correctly. do some a search on "spark plugs" or something and i bet you can find more info. my truck also has an intermittent rough idle that i am working on... so far ive changed the fuel filter, and this weekend im changing out the plugs and wires with a fresh set of motorcraft's.

 

[RF76]

I'm putting the old plugs back in, Bosch.

There was nothing wrong with them but the HPTV bit sold me on the E3's.

 

[RF76]

I didn't take the e3's out, I put about 50 interstate miles on it and now it idles like a champ. Go figure......

It does still idle a bit high (not much) until I come to a complete stop but it's always done that. I can start the truck and once I coast backwards it immediately jumps 100 rpms, it's done that for almost 100,000 miles.

Anywhoo, back to normal for now.