Rich Exhaust Smell

[87Dodgeman]

I have an ’87 D150 with 318/auto. The engine is all stock with 2 barrel Holly carb (recently overhauled) and the original converter. The engine runs perfectly, idles very smoothly, starts up first time every time, no hesitations or stumbles, no smoke, good power & throttle response & 15 mpg which I consider about right for this truck. But the exhaust smells noticeably rich at idle. I’ve checked the plugs and they are a nice tan/white color as they should be. The oil doesn’t smell ‘gassy’ and everything seems great. Even when driving in stop & go gridlock with lots of idling, the engine never loads up or behaves in any way that might indicate any problem. So, I’m hoping someone might have some clues as to the source of my overly rich exhaust smell?

[87Dodgeman]

I discovered source of the problem. When I overhauled the carb, I didn't adjust the idle mixture screws in enough. Didn't seem necessary as the truck ran great. I got out the vacuum gauge this afternoon, and went through the procedure. Truck still runs great, maybe a fuzz better, but the rich smell is gone. I'm happy!

[charlie1935]

Good deal. I've had a carb kit for my 87 D100 on the shelf for 3 years and it ain't helped it a bit. Guess I'll have to make use of it. :D :gr_patrio