EGR Issue?

Hi. I have a 87 Chev Caprice with the 305 and a 4 Barrel Carb. It has 180,000 miles on it and has been sitting for a month or two. The motor runs pretty rough at idle...also at idle I can smell what amounts to, but stronger, exhaust inside the car and under the hood when idling. When I take it for a test drive, under load, the smell goes away, and it runs fine. It's just when it is idling that it operates very rough and the exhaust smell is apparent. Also, as it idles, a carbon-like substance comes out of the tailpipe. The cap, plugs and wires are all new and the catalytic converter is relatively new. I've played with air and fuel mixtures on the carb and it doesn't seem to affect the way it runs. I have yet to play with the EGR at all.....What do you think?

 

[evelrod]

jc355---To have an operable Chevy @ 180,000 miles---you have done well for yourself. Consider---the EGR is a vacuum operated , spring loaded valve. Simple, yes, but it either operates or it doesn't (to state the obvious). If it is stuck open, low speed performance and idle will be compromised. If it is stuck closed, emissions will be well out of specs but performance may not be affected. As to the carbon in the tailpipe, at that mileage, I would not hazard a guess without further explainations. The possibilities include excessive oil consumption, rich mixture, clogged intake system , ECU problems, and on and on. The smell could very well be leaks in the exhaust system, and if that is the fact, you should take care and be wary of CO poisioning.


Rod

 

[sbc]

see posts on pg. 1 lots of info