Date: Tue, 9 Sep 2003 14:12:26 -0600
Reply-To: Steve Blackham <ssblackham@MAIL.BIGZOO.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steve Blackham <ssblackham@MAIL.BIGZOO.NET>
Subject: Re: HC high at Idle - Any Ideas?
In-Reply-To: <Law9-F96o2omjpD3zCP0000168c@hotmail.com>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"
There are several causes for High HC, basically unburned gas.
Excessive richness cause by a fault in the injection system. high
fuel pressure, bad temp sensor, bad O2 sensor, a bad plug, bad
timing, etc. You test the easy things first . Timing and plugs,
then you check the others depending on what the plugs tell you.
Steve
>I falied CA smog with high HCs on high rpm test. Took to a vanagon
>place to repair before I retook test. They said my timing was way
>off and adjusted it. I past smog yesterday with flying colors. My
>high rpm hc lmit was 180 and I had 344. After the timing fix, it
>was 29.
>
>
>
>
>>From: Steve Blackham <ssblackham@MAIL.BIGZOO.NET>
>>Reply-To: Steve Blackham <ssblackham@MAIL.BIGZOO.NET>
>>To: vanagon@GERRY.VANAGON.COM
>>Subject: Re: HC high at Idle - Any Ideas?
>>Date: Tue, 9 Sep 2003 13:03:23 -0600
>>
>>Phil:
>>
>>A leak in the exhaust system upstream from the O2 sensor will also
>>cause your symptoms. Check for leaks and bad gaskets. Put a rag
>>over the tail pipe and listen for leaks. The exhaust leaks cause the
>>O2 sensor to think its running lean from the air leaks. It
>>compensates by enriching the system. The volume at open throttle
>>keeps the air out so the O2 sensor operates normally
>>
>>
>>Steve
>>
>> "Walker, Phil" <Phil.Walker@BROOKS.COM>Wrote:
>><Subject: HC high at Idle - Any Ideas?
>>
>><Well it is inspection time again, only this time I am having emissions
>><problems.
>>
>>My 2.1 engine has about 30K on it and the rotor/cap/plugs were changed about
>>20K ago (3 years). I went in for the emissions and inspection and got the
>>following feedback...
>>
>>RPM 2550
>> HC CO
>>STD 220 1.2%
>>Read 59 .61%
>> Pass Pass
>>
>>RPM 895
>> HC CO
>>STD 220 1.2%
>>Read 505 .26%
>> Fail Pass
>>
>>So I combed the archives and I found a post from Steve Blackham in 2001
>>(Steve happens to live about 5 miles from my house!). He was having the same
>>scenario and he documented (quite thoroughly I might add) how he addressed
>>the problem. Most of the fix stemmed from an adjustment of idle and timing.
>>
>>I emailed Steve to get some more advice and he recommended I check the plugs
>>because he thought I might have a leaky injector. Tonight I checked the
>>plugs (all white - chocolaty). While I was getting to the plug under the air
>>filter I noticed the clamp on the engine side of the AFM was very loose from
>>the fuel line job I did a couple of weeks ago (YEA! - I got that done). I
>>basically never tightened it (good thing I've only driven to the inspection
>>since!). Could this also be contributing to the high HC at IDLE? Maybe the
>>O2 sensor is showing lean from the extra O2 so the computer is squirting
>>more juice?
>>
>>Anyway, I'm going to correct that, but I want to do anything else to make
>>sure I pass for sure when I go back. I don't have a timing light, so I
>>hesitant to jump into the idle and advance. The idle is around 900 and
>>although I told Steve it might be a little rough, I'm really not sure. It
>>has never idled like my old Acura legend, but it doesn't hunt. It just
>>seems....well....you know a little weird, but after all it is a VW!
>>
>>I took a look at the cap and rotor and they look descent, but there was
>>nothing suspicious.
>>
>>Any other advice would be helpful. I'm going to do plugs, cap, rotor, and
>>air filter (it's dusty out here in Utah on those dirt roads!) just to be
>>sure.
>>
>>Steve, thanks for the email. Your advice was helpful.
>>
>>Phil
>>89 Westy
>
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