Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec ?Help tracking down the stuttering problem....Long...

I think that you should try that restrictive airfilter trick. I remember getting my paper element wet, and it did reduce airflow.

I am convinced that my car is running too lean when in CL operation because my exhaust is so large. I am going to put the stock exhaust back on, reset everything, then see what happens. If the stuttering issue goes away, then I know that the SVT PCM will not allow me to move that much air through at low rpm.
The pcm from a 00 3L with oval intake runners might be able to do it, but they don't support manual transmissions, or IMRC points.
I looked, and the Jaguar S type has the 3L with a manual transmission. That pcm might be ideal. I'm going to contact Terry H. about possibly getting one.
In the mean time, I will get the exhuast put back next week, then let you know what happens.

The other best possible answer that I have is a variable fuel pressure regulator, but I don't know of any that would fit our car.

Good luck.
warmonger

The Duratec 3L PCM will support a manual transmission and IRMC (at least a 98 module). You will have to swap some pins to make it work.

...BlackPantherSVT,

Here is an interesting story concerning EGR...

"Focus Flutter"

Have you tried disabling EGR?

...Ed

Hi All,

Here's something interesting...certainly not for me...Tom??

EECSucka

EEC-IV and a little V data

Funny name for the first one.

...Ed

More stuff...I've been searching like a fool!

New EEC

...Ed

And more!!!

more EGR woes

...Ed

EDIT: MORE! DPFE

Phew...it's late! I really think BlackPantherSVT is on to something with the EGR! Hope we get some answers soon!

...Ed

Well...morning has come..

I went out and tried a few things and got subtle results...nothing FIXED it completely.

Prior to the following checks I removed the DPFE and checked to see if there was any evidence of corrosion or carbon fouling. It was sooty but showed no signs of being gunked up or moisture contaminated. You can't see much of anything down the two ports. I shot some carb cleaner down the ports and "aired" them out before the runs.

First I disconnected/plugged the vacuum hose to the EGR valve diaphragm and it seemed a little smoother.

Next, reconnect vacuum hose and disconnect the DPFE connector...that produced the best results, however it was not gone.

Third, I left the DPFE disconnected and also disconnected/plugged the EGR vacuum hose...not much if any difference from the previous run.

Conclusion...this might be a contributor, however I don't think it is the total answer.

...Ed

I checked the vacuum regulator solenoid with instructions in my CD manual...it says it's supposed to have 26~40 ohms resistance across the solenoid coil. Can I assume that means across the connector contacts? (how else would you do that?) If so, mine reads "0". That means... its shorted? Another contributing factor?

??????????????????????

...Ed

Wow my car was stuttering very bad today. It did it the whole way up the RPM band. It felt like the IMRC was opening and closing all the way up to redline. I have spring break in a week so I will be bringing it in to a shop to get some advice and if I have enough money have them fix it.

Later,
Chris

To all: I decided to test the egr idea. I plugged the end of the rubber boot going into the EGR valve, I disconnected the DPFE sensor, and I disconnected the egr solonoid. Basically, the car had no way of using the egr system. I waited till operating temp and drove around. No help at all. In my mind, this says that it isnt the control of re-introduced exhaust gas that is causing the stuttering - this further reinforces that it is the PCM fuel management strategy for part throttle (non idle/wot) cruising and acceleration. Of course, after this test, I normalized all the tubing and sensors. This week, I am going to investigate the different PCM's used and the PCM's on svt/v6 mn's that do NOT stutter. Maybe if we start a list of who has what PCM number we can find a pattern? Something to try. You know, we may be dealing with faulty/corrupted PCMs that just have to be re-flashed/replaced... IF there are a large number of 99/2000 svt and reg v6 manuals that do NOT sutter that have the same PCM's as we do, then it def. is just corrupted/faulty PCMs or the code in ours need to be reflashed with what is in the PCMs that dont stutter (that match us). I really want to find out the PCMs / tear tags of those who have no stutter or hesitation, who match our vehicles, to try and confirm this. TtEl!