Feels like a misfire under load 🤷****♂️

[blue62]

Originally Posted by ike84

the injectors for the 2.7, 3.2, and 3.4 are all the same from 00 - 02. the dme just runs them on different duty cycles to adjust for different fueling needs.

these injectors are no longer being made. they were a special part made by bosch specifcally for porsche. you can remove yours and send them out for cleaning and testing (which costs about $30 per injector plus shipping), buy a remanufactured set from a company called reman, or do the 986.2 injector swap. If youre worried about the injectors, I recommend the latter - you can get them for $25 a piece and the modification takes less than 5 min per injector with a dremmel.

before you do this though, do as blue says - repeat your vac test. if your vac is still low then you haven't fixed your problem. bad injectors dont cause low vac pressure.

Actually anything that causes a misfire results in what is called "cylinder power imbalance" which results in a drop in vacuum for the cylinder or cylinders experiencing the misfire. It is commonly seen as a "tick" of the vacuum gauge needle when the misfire occurs.
The needle reacts very much like a single cylinder valve train issue. (if it is a single cyl misfire) or multiple cylinder valve train issues if it is multiple cylinder misfires.
The needle action is identical in some instances.

[blue62]

Colacharlie,

This is going to sound crazy:
With the recent work done on your car (the Variocam work).
Was any of fuel injector wiring disconnected????
If it was go back thru them and make "certain" the right wiring connector is connected to the proper injector.
A Fella here on the forum has been having a very similar problem as you.
Misfires without any codes. Bogging or judder when trying to accelerate.
He had two injectors crossed up.

Let us know what you find.

[colacharlie]

Originally Posted by blue62

Colacharlie,

This is going to sound crazy:
With the recent work done on your car (the Variocam work).
Was any of fuel injector wiring disconnected????
If it was go back thru them and make "certain" the right wiring connector is connected to the proper injector.
A Fella here on the forum has been having a very similar problem as you.
Misfires without any codes. Bogging or judder when trying to accelerate.
He had two injectors crossed up.

Let us know what you find.

Good thought and point that buddy and a good check for anyone going through anything similar…. for me though it’s all good as I was able to replace the variocam etc from underneath with no need to remove the injectors or their rail 👁👍

[blue62]

Originally Posted by colacharlie

Good thought and point that buddy and a good check for anyone going through anything similar…. for me though it’s all good as I was able to replace the variocam etc from underneath with no need to remove the injectors or their rail 👁👍

Well crap...looks like you want to keep things interesting

[colacharlie]

Originally Posted by blue62

Well crap...looks like you want to keep things interesting

Arrrggghh I am loosing the will to live.

Replaced all six injectors and it’s still the same, plus I’ve got more codes up now ��

Any thoughts on what to do next / what process to follow now I’ve got this **************** list?

[blue62]

Originally Posted by colacharlie

Arrrggghh I am loosing the will to live.

Replaced all six injectors and it’s still the same, plus I’ve got more codes up now ��

Any thoughts on what to do next / what process to follow now I’ve got this **************** list?

My guess and it is just that "a guess" is that you messed up some wiring when you replaced the injectors. Or at the very least some wiring is not connected fully or correctly. Go back and double check your work. Then clear the codes and see what happens.

[colacharlie]

Originally Posted by blue62

My guess and it is just that "a guess" is that you messed up some wiring when you replaced the injectors. Or at the very least some wiring is not connected fully or correctly. Go back and double check your work. Then clear the codes and see what happens.

Okay Blue will do 👍