sedy

My 2000 Crown Vic has a problem that happens occasionally.
While driving slowly in traffic the engine speeds up to about 30 mph with my foot OFF the gas.
Sometimes while stopped the engine speeds up without touching the gas.
I have taken the car to the dealer and another garage with neither being able to see the problem.
It just doesn't happen while in the shop and only happens a couple of times a week but I always have to keep it in mind while driving so I always keep my foot near the brake.
The repair shop said he thinks there might be a tech bulliten on this but he wouldn't produce it and I couldn't find anything on my own.
The car does not return any computer codes that could shed any light on the problem.
The car was a corporate lease car (not a police car) that was purchased at 30,000 miles and now has 76,000 with no other issues.
Does anyone have any idea about this?

BlueSteel

Does it start pulesating when at an idle. Also does it do it when it warms up or when its cold? I had a buddy with a similar problem. He had a 4.6 ohc that when it warmed it pulesed and ran high rpm every now and then. Found out the chain for the cams was warn and stretched. Every time the tolerence for the chain went over the computers limit it would raise the RPM in order to correct the error with a dienostic aperiently. We replaced the timing chain and oil pump along with spark plugs and never had the problem again.

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Blue Anodized Steel
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