BAD EMISSIONS PROBLEM! HELP!
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
BAD EMISSIONS PROBLEM! HELP!
My brother brought a 72 coupe without an engine for $1500. Needs alot of work but hey, its a start. He installed an engine out of an 88 Monty Carlo that he had laying around. The install was simple and the car runs good BUT it has extremely high hydrocarbon emisions. The engine is stock 305 with 120,00 miles on it with a stock rebuilt Q jet. The car has a good high flow CAT and stock exhaust. The engine is sound and does not smoke at all.
The EGR valve is in good shape and works . The EGR diaphram is intact, holds a vacuum, and if you lift the valve manualy it stalls the engine like it is suppose to but the selonoid that controls it does not seem to be working properly. Would the EGR operation cause this problem? The valve remains shut even at part throttle. What else would cause extermely high hydrocarbons from the exhaust. Man it makes my eye water something fierce!!!!!!!!!!!!!!!!! :sad:
ANY help at all would be MUCH APPRECIATED! :thumbs:
The EGR valve is in good shape and works . The EGR diaphram is intact, holds a vacuum, and if you lift the valve manualy it stalls the engine like it is suppose to but the selonoid that controls it does not seem to be working properly. Would the EGR operation cause this problem? The valve remains shut even at part throttle. What else would cause extermely high hydrocarbons from the exhaust. Man it makes my eye water something fierce!!!!!!!!!!!!!!!!! :sad:
ANY help at all would be MUCH APPRECIATED! :thumbs:
Burning Brakes
Joined: Nov 2000
Posts: 1,040
Likes: 2
From: BowlingGreen KY
Re: BAD EMISSIONS PROBLEM! HELP! (fullboogie)
Carb running way rich, bad egr control solenoid, bad vacumm going to the egr valve. Do you have an air pump going to the cat? If you don't, the air pump pumps air into the cat to help raise it's temp to convert the nox to less harmful stuff.
