Idle Issues

[Markjr]

My truck this summer has randomly idled anywhere between 1500-2500rpm's. It would run fine and totally at random would idle high like this. I cleaned the MAF, cleaned the IAC and nothing happened. The problem went away for a while so I didnt think too much about it even though I knew problems don't fix themselves. Well now its back and here are the symptoms and some solutions I think will work.

Symptoms:
-Random high idling between 1500-2500rpms
-If I shut the car off while its idling high it take about 30 seconds of the engine turning over to start back up.
-When it does start, tons of black smoke poors out of the exhaust (flooded engine)

Solutions:
-Replace TPS
-Replace ETC (Engine Temp Control)

Someone with similar problems on this forum said that replacing the ETC fixed their problem. Due to the sensor going bad it was telling the engine to speed up to warm up. He said he had the check engine light on that put out a code. I do not have a check engine light on and I did a test with the obd2 and nothing seemed out of place. Any solutions or ideas? I do not want to just start swapping sensors. I have cleaned connections and all. Thanks

 

[4-Ripcord]

Seafoam?

 

[SCRunner12]

It's the synthetic...:jk:

 

[Markjr]

Seafoam?

I'v heard of this, what does it do and how would I do it. Looks like it comes in an aerosol can.

 

[Markjr]

It's the synthetic...:jk:

Lol, well it happened before and after the synthetic change.

 

[Markjr]

I just sprayed electrical cleaner on the MAF and TPS plugs, checked all the hoses, then turned the truck on and started bending the hoses slightly to see which one could have a hole in it. Nothing worked. I forgot to mention that the PCV was replaced and the throttle body housing was cleaned out, inside and out.