Archived "Throttles up" on it's own!

[10-9jc]

Completely stock 2005 (auto trans), 70K miles - original owner.



No problems until this strange (to me)... .



Normally drive truck daily, but it has not been driven for two days.

Full tank of fuel. Daytime temps in the hight 80's.



Start truck, put it in gear - start to accelerate - and the RPMs jump.

Wow! Caught me off guard.

RPMs would fluctuate up and down - run rough.



So - try revving the engine (in Park, of course) - take RPMs up to 2K, runs just fine.

Take foot off the accelerator, RPM's drop to around 1K - then jump to 1. 5K - then back to

below idle - like it wants to die. Then "adjusts" to about 800 RPM smooth idle.



Repeated several times - with same results.

After a few more tries - it seems to be "normal" ... . (I think - haven't done a test drive yet).



*NO* codes. Changed fuel filter - old one looked fine, no water.

(Forgot to check exhaust for unusual smoke)



Suggestions, ideas welcome!

Thanx!



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[cerberusiam]

Sticky FCA is the most common source. Try a heavy dose of Power Service fuel conditioner and TC-3 2 stroke oil in the tank.

If you don't run additives all the time or a lot of fuel thru the truck it will tend to gum things up a bit. Without extra filtration the FCA is highly susceptible to minute scoring that interferes with its operation.

 

[10-9jc]

Thanks cerber - will give it a try.

On test drive it ran completely normal.

BTW - I usually give it a it an additive "dose" - but -my bad- got lax/lazy for the last several tanks of fuel.

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