yeah just got my 77 comet 250 insured and at a stop light it really really smells bad - no black smoke just really bad stink and idles a little rough otherwise runs like a dream ?? any help appreciated !
you got a valve or two stuck. It smells like unburned gas? Has a lopey idle? Your clothes stink like gas when you get home? Pull your spark plugs one at a time while it is running and see which unplugged cylinders do not affect the idle. Be aware, those plugs BITE!!! Use an oven mitt or something similar for insulation. Personally, I stick a voltage tester light into the wire to short them out to the frame. Less shocking experience. But it messes the wires up over time.
A '77 should have emissions. My '72 only stinks when you first start it up. Runs a little rich when it's cold. But once it's warmed up and going down the road it don't stink at all unless you stick your face right in front of the tail pipes.
yeah it must be the cat. Where does the egr get it's vacuum signal from the vacuum under/on air cleaner or intake ? Thanks guy's I really don't think it's valves - only 22,000 kilometers on car !
I got mine with around 50k miles (don't know what that is in kilometers, 80km ) and it had 4 stuck valves on a V8. I think the fact that it sat for so long without running would lead to those valves sticking. 1st, check that it is not running too rich, even though this is usually an "idle only" issue. If it is a gas smell, go for the valves. Egg smell is more a catalytic converter issue. If you don't want to work on them mechanically, you might try to add a quart of "Mystery Oil" and see if that works them loose. I opted for a head job instead (found 4 slightly bent valve stems, probably from running them against frozen lifters).
If it is the cat it has to be caused by something. Eggy smell is usually a hot cat and that's usually caused by too much fuel, i.e. running rich.
I am thinking the stuck valves because of the smell COMBINED with the rough idle. On my V8, I really LIKED the rough idle...it sounded low and lopey. When I figured out I was running on only 5 cylinders and had the heads reworked, I picked up ALL KINDS of power, but lost the lope, until I swapped the cam out Otherwise, if you have a bad idle combined with gassy smell, you are probably running REALLY rich...but that can be fixed with the turn of a screw. But that won't affect running rich, only idling rich. Let us know what you find.
I'm thinking catalytic converter also. With it running, take a look at the converter and see if it is starting to glow red hot at the front of it. If it's clogged up, it will get extremely hot. I used to manage a Midas Muffler shop and we replaced many of them for that reason.
