OU8aCHVY2

Sounds to me like you have a couple different issues...Has the throttle body been cleaned properly? "coking" develops around the throttle plate and can definately cause the "bog" and unstable idle sound. If it needs cleaned it is easy to clean just dont do what most people do and just spray the throttle plate with carb cleaner. It has to be completely hand wiped or the problem will reoccur quickly because of the transducent film buildup. Secondly...has a running compression check or a leakdown ever been done? If so and there are no valve spring issues then i would probably look to a coil issue. We need more info to help better..detailed specs would help greatly...what is compression on each cylinder and what method did they use etc.

bell206doc

Ok, The TB was cleaned by hand, i watched them do it, I suggested carb cleaner, and they said that was a NO NO!, The compression test Passed with Only a 5% degeration between 3 cylinders. They went cylinder to cylinder with there equiptment, and it was a wet test i believe. Like i said, Ive been fighting this for a year and a half, I read info off here and relayed my ideas to them.. All COPs have been replaced with no change, and yes they were OEM lol, also PCM update was checked and it had the latest Flash as of
Dec 08

Sxynerd

I think both whitefox and Cliff are on the right track.

The cats can screw with mileage and acceleration. Before this started happening, did you recently run injector cleaner or any sort of "mystery oil" through the engine?

O2's are also notorious for "just being bad enough to screw it up".

And running engine cleaners reek havoc with o2's.

My only other suggestion would be make sure your grounds are good.

bell206doc

Sxynerd, I understand what u mean by engine cleaners, I did not run anything through the engine until all this happened, all i used was fuel injector cleaner and a few months later seafoam, that was a little over a year ago nothing since, After reading replies, I remembered somethin odd, If i just start the car when its cold and go it runs great for a couple of minutes, then crappy, My mechanic has talked alot about open and closed loop
and i believe when its in Closed Loop is when it runs the best

Thanks for the replies and please keep the ideas
comming, I REFUSE TO GIVE UP ON MY PONY LOL

Sxynerd

Do you have a custom tune on your car?

Also, never use seafoam again. They are o2 killers. There is no reason to need to clean out the insides of a 4.6 engine with seafoam or any of the other stuff if the vehicle has been standardly maintained. Sometimes on HIGH mile engines it can even cause the engine to loose a piston ring or worse.

bell206doc

No custom tune, just OEM, and noted about the cleaners, have not used since. I drive and mod my 87 F250 4x4 with 460 more than my pony due to the issues its having, and its killing me lol

cliffyk

Tired, sluggish, and reduced output but "within parameters" O2 sensors will cause exactly this--the lousy gas mileaage and bogging.

The bogging is because it's running pig rich when you first accelerate, once the O2 sensors get a bit hotter as the exhaust gas flow speeds up they are giving the PCM better information, or at least good enough to run better.

I'd replace the O2 sensors 'twas me...

bell206doc

Then thats what I will do, I will do myself, I have spent over $400 thus far for diagnostics with no results, I was told by my dealer to and i Quote " drive it till it either breaks or throws a CEL". I will do it Next weekend, due the Flying schedule being to busy this weekend.

Thanks guys and please keep other ideas comming

sweger

good luck! keep us posted and i really hope this fixes her for ya so you can enjoy it how its meant to be