[BowerR64]

I cant seem to find it on my car but i want to check and make sure its hooked up and working properly.

This is what it looks like, and my engine.

 

[kkspeed]

Bolted to the firewall, to the right (driver's side) of center.

 

[BowerR64]

Bolted to the firewall, to the right (driver's side) of center.

Behind the battery? i dont see it man. What lines go to it that i can see?

 

[whynotthinkwhynot]

I thought the DPFE was integrated into the EGR on this vehicle, but I'd have to run outside and check.

What problems are you having with your engine? DPFE issues are common with Zetecs, but I haven't seen that problem yet on a Dtec.

 

[BowerR64]

I thought the DPFE was integrated into the EGR on this vehicle, but I'd have to run outside and check.

What problems are you having with your engine? DPFE issues are common with Zetecs, but I haven't seen that problem yet on a Dtec.

It just idles really rough and it has ever since i got it. The car shakes and vibrates stuff in my car. If the windows are down a little they vibrate and causes pressure inside the car its really messed up.

I have a feeling its the alternator about to take a dump but i thought ide look at some of the easier things first.

Im about to put on a header and im wondering if i shouldnt switch out the alternator at the same time that way its out of the way to slip the alternator out too.

 

[BowerR64]

I thought the DPFE was integrated into the EGR on this vehicle, but I'd have to run outside and check.

What problems are you having with your engine? DPFE issues are common with Zetecs, but I haven't seen that problem yet on a Dtec.

Is it bolted to the intake?

I went on google and searched the DPFE for a duratec and i couldnt really find much. I then searched "ford focus DPFE" on e-bay and it shows on like in the picture for "05-07 focus" it looks different then the one form the 2000-2004 so i figured there actually is one. I cant find mine though unless its in the same spot as the Zetec wich would be under the fusebox behind the battery. ?

sid enote: i replaced the IAC a few days ago and it didnt help. While the new one is on i messed around with the stock one and it still functions when i put 12V to it. It snaps open and springs closed i guess like it should? or is it a stepped voltage that slowly opens it in small amounts?

 

[jetrinka]

The IAC is run off a voltage duty cycle.

Have you checked out obvious mechanical failures such as in the mounts themselves? Even if an engine is running very rough more often than not the mounts are enough to isolate the vibration from the passenger compartment, at least to the point that it won't vibrate the windows around...

There is a TSB out describing rocks getting wedged in between the subframe and rear engine mount causing a solid connection between the two and vibration. Check out all your mounts. And if everything mechanical is in good condition then look somewhere else.

 

[BowerR64]

The IAC is run off a voltage duty cycle.

Have you checked out obvious mechanical failures such as in the mounts themselves? Even if an engine is running very rough more often than not the mounts are enough to isolate the vibration from the passenger compartment, at least to the point that it won't vibrate the windows around...

There is a TSB out describing rocks getting wedged in between the subframe and rear engine mount causing a solid connection between the two and vibration. Check out all your mounts. And if everything mechanical is in good condition then look somewhere else.

How can i check the mounts? will they look bad? can i wiggle the engine?

If i make a video can you tell by watching the engine if i rev it if the engine is moving to much?

What i dont get is when i removed the IAC and put it back on upside down why it ran so smooth? The idle was higher but it was so much smoother. Thats why i replaced it because when it did that i figured that was it.

It also seems smooth in park and in neutral but in drive its shakes and just runs like crap.

 

[jetrinka]

A visual look at the mounts usually suffices. Look for large tears in the bushings.

Its strange the car would run better with the IAC upside down. I had mine in upside down once and it never found its idle and threw a code repeatedly.

Do you have the ability to datalog?

 

[BowerR64]

The IAC is run off a voltage duty cycle.

What controls the voltage duty cycle? maybe its something before the IAC?

I tested the old IAC but i have checked the plug with a meter to see if maybe its not getting voltage or something to the IAC.

Maybe its in the SCT tune? what is a normal idle RPM?

 

[BowerR64]

A visual look at the mounts usually suffices. Look for large tears in the bushings.

Its strange the car would run better with the IAC upside down. I had mine in upside down once and it never found its idle and threw a code repeatedly.

Do you have the ability to datalog?

Yes i can data log but my wideband is not installed yet. What should i log? i have some past logs.

 

[BowerR64]

I even took my intake off to replace the PCV thinking that was an issue but that didnt even help. I bypassed it thought so now i wont have to worry about it anymore.

Do you know what they sensors are inside the intake? in that picture up there i posted?

When i had my intake off i tipped it on its side and it leaked a bunch of oil out and im wondering if maybe i got some of that oil in those 2 parts on the side where the TB is mounted. The long runner comming down the side from the TB is where it leaked out.

I think it was collected at the bottom of the intake from the PCV tube and i didnt realize it was filled with old oil.

 

[jetrinka]

Boy its been a while since i've seen the pids for the SCT datalogging software. .

Go ahead and log the following. (these are probably not the exact names in the datalogging software you have... Im just going off what I usually see at work on our scantool)

ECT (coolant temp)
RPM
IACV duty cycle or voltage (basically what the computer is commanding)
MAF counts (grams/second)
O2 voltage bank 1 sensor 1
IAT (intake air temp)
If there is a pid for misfire counts on different cylinders, select all of them

I can't think of anything else at this time... lol.

Log these things with the problem happening and we'll see if there is anything weird.

 

[whynotthinkwhynot]

What controls the voltage duty cycle? maybe its something before the IAC?

The PCM. What happens when you turn the AC on? That's the simple test for the IAC. If the idle goes up, then the IAC is probably working.

I tested the old IAC but i have checked the plug with a meter to see if maybe its not getting voltage or something to the IAC.

A more common test is to simply unplug the IAC while the engine is idling. If the idle goes down, then the IAC was doing something.

Maybe its in the SCT tune? what is a normal idle RPM?

Manual transmission should be 700 rpm. For an Auto, I think it's more like 850 in N and 750 in gear.

FYI: those Zetec problems with DPFEs caused missing not low idle. This is typical of EGR related problems. EGR closed= missing at low rpm until engine is warm, EGR open= missing at mid- higher rpm.

Yes it could simply be in the tune, but I would certainly check out the motor mounts especially the lower motor mount. Have you cleaned your MAF? What all have you done to your engine? Do you have a larger TB, for example?

 

[BowerR64]

The PCM. What happens when you turn the AC on? That's the simple test for the IAC. If the idle goes up, then the IAC is probably working.

A more common test is to simply unplug the IAC while the engine is idling. If the idle goes down, then the IAC was doing something.


Manual transmission should be 700 rpm. For an Auto, I think it's more like 850 in N and 750 in gear.

FYI: those Zetec problems with DPFEs caused missing not low idle. This is typical of EGR related problems. EGR closed= missing at low rpm until engine is warm, EGR open= missing at mid- higher rpm.

Yes it could simply be in the tune, but I would certainly check out the motor mounts especially the lower motor mount. Have you cleaned your MAF? What all have you done to your engine? Do you have a larger TB, for example?

Its not that its a low idle its a ruff low idle. Vibrates the car and just doesnt seem quite right.

Ill check that stuff today. Im not sure where the motor mounts are.

 

[whynotthinkwhynot]

One is at the front of the engine, the other is under the battery- but is also called the transmission mount. The 3rd mount, commonly called the dog-bone mount, or torque-strut mount, is located in the center of the car behind the engine. You'll have to jack the vehicle up and crawl under it to find it. It is near where the passenger side CV axle enters the transmission, and is held in by one horizontal bolt on the engine side, and a vertical bolt on the crossmember side.

All 3 are available from RockAuto, I am only unsure if the front engine mount is hydraulic on these vehicles. I think I read somewhere that Ford stopped using hydraulic front mounts in 05. If so, then the aftermarket mounts will be fine.

Since you have a modded vehicle, the mount most likely to be damaged is the torque-strut mount in the rear. Since you might drive you car hard, I suggest either getting the $100 VF poly mount, or poly mount inserts. Before you get the inserts, be sure to check out how to install those in the How-To Archive. It might be more than you want to take on.