[Gimpdiggity]

Hi everyone.

I decided to start a new thread because my other one was a few weeks old now.

I have a 2003 Taurus Wagon. About 6 weeks ago I was trying to pass someone on the highway and the car started bucking and hesitating right around 4,000-4,200 RPM.

I posted on here about it and got some advice.

Here is what I have done to the car in the order it was done:
1. New spark plugs
2. New plug wires
3. New air filter
4. New fuel filter

These were done first, and all at the same time. After that, the problem seemed to be a bit "smoother," but was still there and very noticeable.

After that, we put in a new coil pack and that did absolutely nothing. My mechanic has a pretty good working relationship with the AutoZone here, so he bought one new, tested it, then took it back to them.

I drove the car for a couple of weeks after that because at anything other than highway speeds and high RPMs it still drives like a dream. Finally, it gave me a check engine light. Bad catalyst on bank 2.

So I found out the catalytic converter was still under warranty and took it to the dealership. Today I got the car back with a brand new catalytic converter, the ones that attach directly to the exhaust manifolds.

On the way home, the car is STILL doing the same thing. The guy at the Ford dealership said that it seemed like there was a problem with the rev limiter, and that for some reason it was engaging even while the car was in gear.

I'm stuck on what to do, now. The dealership told me the O2 sensors on the car were still good, so those haven't been replaced. I also haven't replaced the downstream catalytic converter.

Has anyone ever heard of a rev limiter for some reason engaging while the car was in gear?? If so, what is the fix for that??

Any suggestions would be greatly appreciated.

Thanks.
Jeff

 

[nytaurusabuser]

It's cheap enough to do as I suggested before - change out the thermostat. I believe what happens is the heat build up causes a problem with the fuel pressure regulation. Seriously, I had the same issue and the one thing that seems to have 'cured it' was changing out the thermostat.

If that works, then my next suggestion would be to have the cooling system flushed.

I believe you stated in your old post that you thought the thermostat was original.

Maybe it's a crap shoot, but even in your old post, someone suggested fuel pressure.

Another point is in your old post you said it only happened when the car had been driven for a while, not when it was cold - which is why I never chased the rev-limiter.

 

[Gimpdiggity]

It's cheap enough to do as I suggested before - change out the thermostat. I believe what happens is the heat build up causes a problem with the fuel pressure regulation. Seriously, I had the same issue and the one thing that seems to have 'cured it' was changing out the thermostat.

If that works, then my next suggestion would be to have the cooling system flushed.

I believe you stated in your old post that you thought the thermostat was original.

Maybe it's a crap shoot, but even in your old post, someone suggested fuel pressure.

Another point is in your old post you said it only happened when the car had been driven for a while, not when it was cold - which is why I never chased the rev-limiter.

I completely forgot about replacing the thermostat. I will have to give that a shot. It should be a pretty easy and quick fix.

 

[bull geek]

Unrelated to the issue but since you said the car was "bucking", I have to ask...what is the condition of your ignition coil? On the underside do you see any fine, minute cracks in the mold?

 

[sheila]

^+1.

 

[Jeff K]

+2

Classic coil pack failure mode.

 

[sheila]

^ Nevermind, i went back and reread the old thread and saw the coil pack had been changed out. With a new one i hope?

 

[sheila]

Does the 03 wagon have a 3.0 duratec or vulcan engine?

 

[Gimpdiggity]

Sorry guys...I forgot to add that I tried a new coil pack and it did nothing.

I edited that into this initial post so that people will see it.



The engine is the Vulcan engine...at least I think it is. The Vulcan is the lower ended engine, right??

 

[sheila]

Jeff, dont call it lower end or ol rudy will be fetchin his rope (Texas justice). Vulcan is the 3.0 ohv (overhead valve). Duratec is the 3.0 dohc (dual overhead cam).

 

[Gimpdiggity]

I didn't mean it in a derogatory sense!!!

More in a "it costs less" sense!!

 

[sheila]

Eighth digit of vulcan vin will be a U (or 2 if it is flex-fuel?). It will be an S on a duratec. I know not always, but i thought most times they stuck a duratec in the wagons?

 

[Gimpdiggity]

Eighth digit of vulcan vin will be a U (or 2 if it is flex-fuel?). It will be an S on a duratec. I know not always, but i thought most times they stuck a duratec in the wagons?

No, it's got the U in it.

 

[Taurus360]

OK so I have the same problem with my car what is the final solution?

 

[Taurus360]

I can't beleive you stopped short of posted your final solution?????????

 

[Taurus360]

Hey why did this thread stop?

 

[Bigdogg2830]

i would start a new thread with all ur info and what has been done to try to solve it. make sure you post what engine you have.

 

[00greenlx]

I've posted this MANY times (It should be in our search system by now) But take a look at this TSB, sounds like a cam Synchronizer on it's way out.

Troy.

 

[Taurus360]

Thank you