Hi, Thanks, spot on..Markski found that mine came off from FPR when he did his pressure test on it , plus a few other little leaks..I hope that was it also. .
He is going over everything now..
He does know his stuff ,as he said at the beginning it was most likely a leek .

 

Maybe I'm missing something here, but how exactly do you know it's not misfiring? Just because you replaced the plugs and coils doesn't mean it's not misfiring since there are a lot of possible causes for misfiring. A new battery isn't going to make any difference in whether it misfires either. And just because it logs fine when it's warmed up doesn't mean it's not misfiring when it's cold. As a matter of fact, data logging it when it's warm doesn't help you prove anything since the problem only happens when it's cold...

If it walks like a duck and quacks like a duck and misfires like a duck then I bet it's a <misfiring> duck.

 

Thanks for your input,,But a lean condition from what ever source will cause misfires,,basic 101 fueling.
Also no signs or clue off Any coil or plug problems after a few minutes of cold start are over or no signs of missing under load on data log at 1.4 bars or any areas ,runs strong and awesome.
When any engine is cold it needs more fuel and if it it is not given it it will produce these type of signs. Any vacuum leaks will worsen that because the ECU will only compensate for so much fuel delivery.
We will see when I pick it up from Mark.

 

^ i bet when you get over to markskii it will have been sorted. only reason i can think of to be near chi town LOL! good luck john..!

 

Hi,Thanks..Yes, read one of my above posts.

 

HI,Thanks for you input..
A weak battery can cause a misfire as the techs at the Porsche dealer have seen it happen,they told me to get the new battery..
On a cold start up the motor doesn't turn over fast enough for the crank sensor to read at first ,thus a misfire until voltage goes up...Also a bad crank sensor or to big of a gap can cause a cold misfire ..Its not as simple as a coils and plugs sometimes.
As a lean condition can also,,like when cold and or a bad vacuum leak that the computer can not compensate the fueling.
Just sharing info now since I have been gone through this .
So far it seemed Marski found several vacuum leaks ,the main one was the FPR line.
Since fixed it has not done it but it is still it is not a silky smooth cold idle for the first 2 minutes or so like I would like.But I don't think it ever was that smooth since my build.

 

Glad she is improving for you John. I wonder if it's just the cold adding to it?

 

i have never in all of my cars seen the vast number of issues a low or dying battery can mimic that this car can/does. it's confounding in its peculiarity.

on the rare occasions i see a cel, or even when seeing an obd code, i often check or mess with the battery first. i can see it happening. cold? i wouldn't think so. it snows in deutschland.
but hey, ya never know.

 

Yup same thing on my car the hose from plenum to FPR was completely off.

 

HI,, The Porsche Tech at Loeber Motors,Rich H.,who has been a master tech for 30 years told me to buy a battery the first time I brought it in to them for the problem ..My battery was about 5 yrs old and the car sat for a few weeks in the coldest of the winter in Chicago...I posted a thread on Battery purchase.
Well the car sat in the dealer and it was replaced,,the problem didn't happen again but the weather temps went from 0/teens back to 40s after that..NO PROBLEM after that..THOUGHT it was fixed.
But when it went back down to the 20s it happened again on ice cold start ups..Back to square one after that and then all of the above posts for info.
So far no cells or dash board messages after Markski vacuum hose repair.
Hopefully he fixed it.
If it happens again,,I hope it gets that cold again to be sure,,
I was told it could also be the secondary air pump module .
But the above advice about the temp sensor could also do it..
And of course the crank sensor..

 

well it sucks you haven't fully isolated the issue, but that battery thread may be timely for you? a 770 bosch c/a aint bad @ 125$!

but i'll share last months battery issue to illustrate our mutual point about batteries. i regularly trickle charge with a ctek and yet am notoriously lazy, so consequently didn't for a month or two. i drive the car most every day whether i need to or not, and never thought about my 1.5 yr old battery even being near to low on amps.

began to get "cam position sensor low imput" cels!? ordered a new cam position sensor from pelican parts for 50 bucks, put the car on the ctek again, and now am again doing so weekly.. and guess what!?

i STILL have a brand new 50$ cam position sensor sitting in a box lol. was the battery being low is all.

good luck tho john speed.i hope you sort it.

 

John had a similar problem turned out to be a hair size crack on one of the welds on my 3" y pipe.

If u still have the stock y-pipe maybe check ur cooler welds etc.

 

Hi,Thanks ..But Markski did a pressure test and came with other leaks which we thought was the problem..

 

OK,,Has not had any lights come back on since Markski fixed the vacuum leaks and the temp has been warmer out,,,BUT NOW
The temps went back to the 20s yeaterday and at night ,,
When I went to start it up this morning it happened again ,,lights went on and very rough idle for the first 2 minutes only ,,
Then after that is everything fine, idle and drivabilty and no start up problems after that intial overnight cold start up..
Thanks everyone for your input,,time to take a look at the other causes of a misfire condition other then coils or plugs.

 

OK this is one for the books,after the above post,
I put about 100 miles on the car last night going to events including a few stops,,
After one of the stops I noticed the cell light went off and the dash memo didn't appear ...Is that strange or what?
Now to go out this morning and start it and see what transpires.