TheSamba.com :: View topic - Stinky exhaust

Tue Sep 30, 2008 6:15 am

86 Westy Syncro. Bone stock 2.1. Starts fine, runs fine, no hickups. Idles smoothly at 1100 - maybe occasionally surges to slightly above that. TPS switch engaging, but of course I haven't voltage testted to see if it's actually working. Exhaust is smelly at idle - like she's running too rich. I know there are a billion potential causes but wondering if this sounds like a good candidate for an O2 sensor replacement. I just fine sanded all the electrical contacts in the distributor cap and that definitely smoothed the idle from a surgy 1100 to 1200. Probably should replace the plugs too. Advice on the stench? BTW, she passed strict Atlanta, GA emissions six months ago. Thanks!

Tue Sep 30, 2008 7:15 am

dixoncj wrote: 86 Westy Syncro. Bone stock 2.1. Starts fine, runs fine, no hickups. Idles smoothly at 1100 - maybe occasionally surges to slightly above that. TPS switch engaging, but of course I haven't voltage testted to see if it's actually working. Exhaust is smelly at idle - like she's running too rich. I know there are a billion potential causes but wondering if this sounds like a good candidate for an O2 sensor replacement. I just fine sanded all the electrical contacts in the distributor cap and that definitely smoothed the idle from a surgy 1100 to 1200. Probably should replace the plugs too. Advice on the stench? BTW, she passed strict Atlanta, GA emissions six months ago. Thanks!

Hey Dude,

So, smelly as in "rich fuel" smell or stinky as in, "rotten eggs?"

Inquiring minds want to know,

Chester

Tue Sep 30, 2008 7:15 am

Stinky. That encompasses a vast world of pleasances. What kinda stinky? Rotten eggs stinky, like sulphur? or a sort of carboniferous miasma redolent of used motor oil? Because rotten eggs is the cat, and some of them just do that, but the gassy smell might be a tuning issue. Is the ignition timing set up right?

Tue Sep 30, 2008 7:16 am

Rich fuel. Not rotten eggs.

Tue Sep 30, 2008 7:28 am

Tencent - timing shouldn't be an issue. It purrs on the road - no hesitation or hickups. And nothing has changed to my knowledge since she passed Atlanta emissions.
CD

Tue Sep 30, 2008 7:35 am

"Shouldn't." You're assuming. You know what happens when you assume. Gotta walk before you can run; begin with the basics.

Tue Sep 30, 2008 7:37 am

Word.
Ass/U/Me

Tue Sep 30, 2008 9:45 am

There is an intricate relationship of the settings at the bottom end, If the timing is off there, it cascades up the range. The computer has the least amount of options at idle, so it needs to be set up right.

Check the timing, but before you do change out the Temp II sensor. It a form of offerings to the gods of Vanagondium. You may want to replace your O2 sensor at this point as well (pays for itself quickly in saved gas). The other item to check, as you mentioned, is the Throttle Switch. Get those three correct, then check the timing. Adjust the idle as per the ProTraing or Bentley procedures and check the timing again. Sometimes it is a three or four round game.

If you ever get the rotten egg smell, it is indeed your cat, but you also need to change gas stations. It is the fuel.

Get you own electronic versions of the ProTraining Manuals, go to my public folder and get:

86 Vanagon Protraining.pdf
Vanagon Protraining 86-91 Fuel Systems.pdf
Vanagon Protraining Digifant I 86-91.pdf
Vanagon Wiring Diagram.pdf

http://homepage.mac.com/WebObjects/FileSharing.woa...mp;lang=en