jetskied

I just adjusted my CO mixture with the air pump disconected. It was set at 2.7%, but I did did not test drive the car right away. After 2 days I hooked up the pump and went for a test drive. I drove crappy off boost, I thought it was lean. I hooked up the gas analyzier and it read 1.5% with the pump connected. I richened the mixture back to 2.5% with the pump hooked up and it ran better. My question is does the air pump lean out the mixture that much? I know your suppose to adjust with the pump disconected. Any help out there? Or maybe my WUR is not functioning right?

Tom F

Try 3.5% with the pump disconnected. I had a bad experience with a hot exhaust, when the fuel mixture was set too rich. This was from the prior owner, but I'd bet that the mistake came about because he tried to set it with the pump connected.

jhunt@huntinter

The air pump is a sad example of meeting the rule of the law but not the spirit of the law. The CO2 emmissions could not be higher than a certain amount of the total exhaust, so Porsche just added air and hence diluted the bad stuff. Did not reduce the bad stuff.

Should not have been allowed if you ask me.

PorschePhD

John is so correct here. If they wanted to really keep the exhaust clean a CO reading wihtout a hair dryer in the tail pipe would have yeilded a "real" reading. Talk about pleasing the political powers.

Make sure that the car is at operating temp when you go to set the CO. Unhook and leave unhooked the air injection. Set the CO at 3.5ish. This will allow a little give one way or the other is your machine is off. Try that and see what happens.

S4drifter

Sorry to hijack this thread but......
Can anyone point me to a resource where I can learn how to adjust the CO? I am not completely mechanically dis-inclined, but new to these engines. I am still having the surging engine/black smoke issue and can find no leaks around the IC. Stephen had suggested checking the CO but I have no clue how to do this. I have the 101 projects for your 911 book but there is no reference in there. Or, am I just better off bringing it to the shop? (but I don't learn anything that way). thanks

A930Rocket

Get one of the Gunston (sp?) gas tester to check your CO.

Here's a pic showing which way to richen and lean the A/F.

estrellajon

How do you disconnect the air pump and where is it located?

jetskied

It is on the drivers side behind the air intake pipe to the turbo. Its a hose you can disconnect.

estrellajon

Thanks, is it underneath the intake pipe or right to the left of it?

jetskied

More to the left, it is a fiber braided ruber hose with a clamp on it. Its about 1/2-3/4 inch and mounted to the pump. Check the pelican web site. They have a part book veiw so you can see it.

estrellajon

Great for the direction. I will go that way.