2000 Vic 'missing' at cruise & idle

[oovah]

My 2000 Factory CNG Vic w/ 61,000 miles has a hesitation while running at a constant speed. This could be idle, 30 mph or 60 mph. This clears up when I accelerate, but the outside or engine temperature do not seem to have any effect on the symptom.

The hesitation almost feels like a missing ignition spark, so I am suspect of coils / spark plugs but, not being a mechanic, I understand that fuel injection / delivery could be a cause as well.

Any input or previous experience with these conditions?

Thanks, oovah

[hoofnit]

Re: 2000 Vic 'missing' at cruise & idle

Two issues that can be affecting the hesitation. COPs (Coils over Plugs) do slowly fail or allow moisture in through micro-cracks in the boots. Ford replacements are pricey, but you can find white label ones on Ebay that work just as well. The removal and replacement is pretty easy for a shade tree mechanice. A dirty MAF (Mass-Airlflow sensor), the electronic device on the air intake, can also provide an inaccurate reading to computer and cause hesitation as well. Cleaning this requires specialized tools and solvents.
You can find more infomation on non-CNG related issues with Crown Vic engines and powertrains at http://www.crownvic.net

[happily]

Re: 2000 Vic 'missing' at cruise & idle

I just started experiencing same in my contour and I believe it is the maf sensor......I'll let u know saturday how it turns out

[fquinonez]

Re: 2000 Vic 'missing' at cruise & idle

Was there any more input on this one? I also have the same issues on my 97Crown Vic.

[happily]

Re: 2000 Vic 'missing' at cruise & idle

finally found mine.......it was a vacuum hose on throttle body, but spark and maf sensor can do it..............also on my throttle body in my contour is a idle control motor with can cause this. try unplugging the maf sensor and idle control motor and see if it runs better unplugged

[Conundrum68]

Re: 2000 Vic 'missing' at cruise & idle

I had the exact same symptoms.
Mine was one dead spark plug and one half-dead spark plug. One measured open circuit from electrode to tip and the other measured 22k-ohms (all the good ones measure ~5k-ohms).

Additionally I found that the crimp-style hose-clamp that secures the plastic intake plenum to the rubber adapter on the throttle body was not grabbing any more, and I had a substantial vacuum leak at that point.
Replaced it with a screw-type hose clamp and disconnected the battery for 20 min to let the engine computer forget the way it tuned itself to the formerly lean mixture conditions.