[andysZX3]

I did a search, but everyone has modded Focuses it seems. My '02 ZX3 has developed this problem where it sort of lurches or stutters when I am trying to hold a constant speed in 2nd, 3rd, or 4th at somewhere between 2500 and 4500 rpm. It doesn't seem to happen at highway speeds or when accelerating.

I tried some Castrol fuel system or injector cleaner, and it almost seemed liked it helped initially, but now it's back after about 100 miles or so.

The car has about 32,000 miles, and is still under warranty, but I know that the dealership will just say that they didn't notice it. What could be wrong? What can I do?

 

[MichaelXi]

I'll go on a Limb and say it's 90% likely it's your DPFE Sensor, and Should be covered by the Dealer.

 

[Ray]

I did a quick search and got some part numbers

 

[andysZX3]

Thanks a lot guys. It's possible that this thing would already fail after 32,000 miles? Given the history of the Focus, I wouldn't be too surprised. But, this would be the first problem I have had with it.

 

[mycannon]

I would say the DPFE sensor.

 

[AtBlue5spZX3]

How much would the DPFE sensor be OFF warranty??

 

[Focus_Is_Art]

Try this,
1)next time when you have the problem see if it is below 1/2 tank of gas
2)go fill it up and see if the problem is still there.
1) + 2) = fuel pump

If not the fuel pump it will be more like TPS. Like other said dpfe is possible but I is more likely fuel pump or TPS.

 

[Jibberish18]

I have a similar problem but it doesn't happen very often at all. It only happens at very low RPM's when I am trying to hold the speed steady or when I lightly have my foot on the gas. It does it for a split second. I always thought it may have something to do with the TPS but maybe I'm wrong. It just seemed like an appropriate candidate.

 

[andysZX3]

I'll go on a Limb and say it's 90% likely it's your DPFE Sensor, and Should be covered by the Dealer.

I just wanted to say thank you and you were 100% correct. I called the dealer, and they said that this was probably correct, and that they believed that Ford even extended the warranty for this part. Apparently, it is prone to water intrusion (the service guy even said that it was a bad design). So, to anyone else that is having similar problems, I would urge you to call your service dept.

Once again MichaelXI and other, thank you!!!

 

[firstonraceday]

I have a brand new pzev 2000 miles and i notice the hesitation at 2000 rpms in 3rd and 4th i was hoping to get some air induction to see if it would help it probably will, but now you have me thinking about tht dpfe sensor

 

[andysZX3]

You'll have to wait for responses from the gurus, but if you have driven in a bad rainstorm or through puddles, or possibley hosed your engine off, it seems that it could be feasible.

 

[MichaelXi]

I'll go on a Limb and say it's 90% likely it's your DPFE Sensor, and Should be covered by the Dealer.

I just wanted to say thank you and you were 100% correct. I called the dealer, and they said that this was probably correct, and that they believed that Ford even extended the warranty for this part. Apparently, it is prone to water intrusion (the service guy even said that it was a bad design). So, to anyone else that is having similar problems, I would urge you to call your service dept.

Once again MichaelXI and other, thank you!!!

Thanks.

And, You're Welcome.
Yup, I've been through two of them.
They are usually THE Culprit behind "Steady-Throttle" Stumble.
I also recognize an O2-Sensor stumble pretty well, and I'm afraid that I have one as of Tonight.
The way it really shows itself is to drive slowly, in a gear that has your RPM around 1500, and Floor it.
If she falls flat on her face, it's Lkely an O2 sensor, or something related to it.
I'm Hoping mine is still covered, whatever it was that happened tonight.

Money's too tight to go fixing things, and I don't know yet if it's MY Fault, or just a simple sensor-failure.

 

[forge]

Hey guys, quick question here. I have a 2000 ZTS and have noticed a really bad stumble developing in my car that's every 6 seconds like clockwork at 4k rpm and when I took it to the shop they just said it's probably the plugs and didn't look at anything since maintinance isn't covered.

I've got just over 50k miles on it so I went to replace the plugs and when I pulled the boot it was covered in rust along with the entire enclosure housing the spark plugs. Seems to me like the headgasket is blown letting water and/or coolant in there. Has anyone ever seen something like this before or know what else may have caused this?

Also, at times when I have needed to give the car some gas to get into traffic the car would hesitate really bad at 4k rpm or so and start to decelerate and buck like it wasn't getting fuel and/or spark then it'd be fine if I went easy on the gas and kept movin' right along.

I'm bringing the car back to the dealership monday. If the problem is more severe they may end up having to swap the motor since everything is still under Ford Warranty. Please help!

 

[EggYolk]

Mine aren't "covered" in rust, but oxidation is visible - on the boots and inside the head. BTW, I have 30k miles.

 

[forge]

I just don't understand how the head could be so oxidized. The car is still pretty new and the head is literally *bright* orange inside top to bottom. The car doesn't have an excessive amount of mileage on it, standard maintinance, no other noticable issues, yet the level of oxidation is unbelievable.

Thanks for the info EggYolk.

If anyone else has any insite please feel free to let me know. I'm going back to the dealer tomorrow to see what can be done.

 

[EggYolk]

Let me just clairify what I said a little bit. When I say the head has oxidized a little bit, it's only in the spark plug area (the little "valley" in the middle where the plugs are), not anywhere else. Outside the of head or except in that "valley". I re-read wrote I wrote and thought this would be a little more accurate.