Idle problems + misfire

[Knockout87]

H!

 

I have an 996 - 99mod manual 3,4L.

 

When i start up it seems like it misfires. It`s kind of a knocking sound. Sometimes it stops on idle.

When i push the throttle for a ouple of seconds, it smokes a lot and then the knocking goes away. 

After that, I let it Idle - but it slowly rises from 800rpm to around 2000rpm, then it drops to 800rpm again and do the same thing over and over again,

 

Does anybody have a clue?

 

This is the fault codes i found:

 

P1601  -CAN timeout - instrument cluster

P0600 - CAN timeout Tiptronic

P0102 Hot film MAF sensor (erased and didn`t come back)

 

 

60 - Central locking limit pos

13 - Left door secured, but not locket

14 - Left door secured, but not locket

16 - Signal from airbag

1 - Doors secures and terminal 15 on

43 - passenger - side release stuck

44 - Driver-side release stuck

61 - Central locking limit position Unlock not reached

 

 

 

 

[kbollaert]

It's been reported that these cars will show up with several anomalies like yours when the ignition switch is failing/about to fail.

I don't encourage throwing parts at a problem until it goes away, but at the price of a replacement switch, it's a "start". I keep a spare switch in my car: it failed once before and stranded me.

[Loren]

Clear all the codes and see what comes back.

None of those codes including the MAF code could cause idle issues. You can unplug the MAF and the car should still idle fine.

 

 

[serbox]

I had similar symptoms with my 2000 boxster but the codes were 1128 and 1130,so this may not help you but it did fix my issues.

I will add that I replaced the MAF twice with no success until I read that the fuel filter could be the issue.

Well, I replaced the fuel filter, the MAF and added Techron to the gas then I cleared all the faulty codes, disconnected the battery for 5 minutes and started the car, It coughed for a few times then started fine...I have to add that it has been really cold here in Colorado so I was expecting a rough start. I drove the car today (Dec 13) to work with no issues and no error codes. I learned that provably the gas filter was not allowing enough gas to start the car in cold. Cheers