Navaros911

Guys,

I need some help again.

There is a very good guide related to cleaning the ISV and the air-flow meter. Click here for the Rennlist thread. There is no need for me to describe the process it has been described in good detail many times before.

My main question is: What do I use to clean the air-flow meter?

The ISV I cleaned already with some carb cleaner. Pics are below.

Secondly: Can anybody identify the parts in numbers 1 through 8 in the picture below?



1/ This seems to be closed off. I've seen something connected to this in pictures of other cars. The electrical connector that connects to something here on other cars seems to be disconnected (but it looks like that's what it should be). It can be seen just above the arrow numbered 2.
2/ This has a connector with a Mercedes logo on it Then there seem to be some vacume lines leading to/from it.
3/ Where is this vacume tube going to?
4/ Where is this vacume tube going to?
5/ Where is this vacume tube going to?
6/ The cable connected to the circled part is going down to the case. Where is this going?
7/ This vacume line seems to go to some solenoid and may have something to do with the resonance flap/valve. What is it for?
8/ What is this little cylinder?

Here's a shot of the air-flow meter:


Both the parts ready for cleaning:


What does this little cylinder do? It seems like a vacume container:


The ISV clean:


Thanks for your help guys!

Navaros911

Guys, come on... How do I clean that air-flow meter?

Cosmos99

I haven't done the job on a Porsche yet, but I used a MAF cleaner that I picked up at the local auto parts store. Make sure is says its safe for airflow meters / MAF safe.

Navaros911

While I was blasting the hell out of the air-flow meter with contact spray I noticed some liquid was visible at the joint between the airbox and the meter.

Some closer inspection confirmed this and if liquid can pass by it, so can air... and it will throw the metering off.

So off came the meter from the airbox and... no seal was present. Someone (probably the dealer here) must have taken the parts apart and didn't replace the seal.

The car was hunting intermittently and I hope this was the cause. The parts are on order... a seal and an airbox clamp (that was also missing).

Here's a pic of the parts, before the airbox got cleaned. Also one of the bushing like metal rings is missing from the air-box.

Rocket Rob

Does this help? I can't remember which Rennlister created it but its very handy.

PNine64

Rob, I've spent the last half hour looking for that pic so could post it to his Pelican thread. Time to download and archive. TY!!

Ryan360

Rob- very nice. who ever created it, really took time to labeling it.

mac109

Thanks Rob.....

Navaros911

Time to update this thread as well.

What I did after ordering a new seal as in post #4 was open the air meter cover and spray it with contact spray. Then sealed it again with silicone. Put everything back together (with the newly ordered seal) and voila!

No more stalling issues.

Silvertarga

*I never use silicone sealer near MAF or O2 sensor..., fumes can cause problems...just sayin...

altarchsa

That gasket is only there to seal the air box to the meter to keep dust out of the meter.

The joint is outside the air intake point for the airflow meter. A leaky gasket couldn't throw the meter off. The meter doesn't know whether the air is coming from a leak, a removed filter, through a clean filter, a dirty filter, etc. It only measures how much air goes THROUGH the meter, not where it comes from. I'll bet the difference between air volume through a new air filter vs a dirty filter is much more than the volume of air coming through your leaky gasket.

Even if the air box were completely removed, the car would run basically the same (except maybe a litle better because it could get more air).

anto1150

964s don't use MAFs, but a much simpler flapper system which only reads the quantity of air, not the type of gas/fume getting through the system.

anto1150

I think it would probably run a little better at high revs, but it would likely loose something in the low/mid area.