Rotten Egg Smell From Exhaust

[DuallyGuy]

I tried to search for a similar thread but couldn't find one. Forgive me if there is one out there. I've been going through my truck pretty consistently for the past year. I'm aware I have a 454 TBI, but I still think that my fuel is being used up just a little bit faster than it should. I also have this rotten egg smell coming from my exhaust. So I'm guessing that maybe unused fuel is getting by? Any suggestions? Thanks in advance.

P.S. Can someone also recommend a good donut gasket at the exhaust manifold flange? The guy I took it to put these cheesy flimsy donuts on and twice they've blown. Thanks

 

[87sierra]

rotten egg smell means there is to much un-burnt gas getting to the catalytic converter

 

[DuallyGuy]

What can I do about that?

 

[Jims86]

Do a compression check, look at the plugs. Maybe got some high sulfer gas too...dunnonhow that would happen in Cali though.
Usually happens when you floor it.

 

[87sierra]

it could be possible that the exhaust leak is causing a lean mixture in the exhaust system and the o2 sensor is trying to fix it by adding more fuel

 

[DuallyGuy]

The smell's always been there. I bought the truck just over a year ago. Even when the exhaust was ok it still had that bad smell. I just assumed it was some bad gas or something. But it's never gone away.

 

[DuallyGuy]

There's no smoke exiting the exhaust pipe or anything odd as far as the engines performance. What could be the likely cause?

 

[87sierra]

another is to look at the spray pattern of the injectors they should be a fine cone spray also a cheap possible fix is to install a fuel pressure regulator which uses a heavier spring making the fuel pressure higher this is what I have been told and I did this to my truck but I don't seem much of a difference

 

[Jims86]

another is to look at the spray pattern of the injectors they should be a fine cone spray also a cheap possible fix is to install a fuel pressure regulator which uses a heavier spring making the fuel pressure higher this is what I have been told and I did this to my truck but I don't seem much of a difference

Yup, and a good way to check thte pattern, is to hook up antiming light to the coil wire, and point the light at the injectors.
No No on the heavier regulator spring, either replace, or have the injectors sonically cleaned.

 

[87sierra]

okay thanks for the info about not using the heavier spring and when I compared my old spring to the new one they looked identical so I think it was the same tension

 

[chengny]

From the 1987 Fuel & Emissions (including driveability) manual - and the link to the whole manual (262 pages):

http://depositfiles.com/files/ohagdkmqx

 

[DuallyGuy]

Thanks for that info and for the paperwork. According to that page, I have noticed that my truck idles high when it gets hot. Not too high but def higher than it should. I've searched high and low for a vac leak. Maybe I just don't know how to check. The fuel injectors seem to spray just fine. I just inspected them last weekend. I wish you guys were my neighbors. LOL Come over and check out my truck.

 

[eastcoastmat]

Ive always thought that a rotten egg smell was a plugged or over heated catalytic converter.

 

[1986K5Wa]

My exhaust smells like alcohol, after being drove a bit. Is it to lean?

 

[MrMarty51]

My exhaust smells like alcohol, after being drove a bit. Is it to lean?

OH crap, another truck having to go to them A.A. meetings.