So I own a 1974 ford mav with 250 6-cyl. I have had the car for the past four years now with out any problems with emissions however, the past year to keep the car running i had to make some serious repairs. Radiator, replacing and removing vaccum hoses, switching to a breakerless ingnition system, new spark plugs, wires, rotor, and cap, ignition coil, etc. Now I took the car in for emissions and it failed so here are my results: Hydrocarbons: loaded reading 397 ppm out of 400 ppm passed idle reading 1198 ppm out of 400 ppm FAILED!!! Percent of Carbon Monoxide : Loaded 0.16 out of 3.75 Pass Idle 0.27 out of 5.00 Pass If any one has any ideas what could help make this car pass emissions that would be awesome!!!!!!!
your timing is way off, and your idle is too low.. i would set the timing and adjust the idle to idle around 1000-1200 rpms. this will help the car to burn off the excess hydrocarbons while it is idling the hydrocarbons is unburnt gas. if the car is not running efficiently, it wont burn the extra gas. and the timing is the first thing to look at. i had the same problem in tucson when i had to worry about emissions. also check your spark plug gap and make sure the gap is set right.
Wow, I always assumed that in the emissions controlled areas, the older cars would be exempt or grandfathered in. Good luck.
a healthy dose of isopropyl alcohol, or methanol usually helps me. just had my 88 van flunk. cleaned up the idle & added 20% methanol. 2nd try was a fast pass.
You can also buy stuff at the Auto Parts store called Guaranteed to Pass it is an additive for the fuel.
the addtives wont work that well if the car is too far out.. i found that out... and i am still waiting for the money they owe me for the Guaranteed to Pass stuff
Dang... when a State has harsher laws than CA... you know you are in trouble!!! We don't have to smog anything 1975 and older...
I'm glad we dont have emissions testing here. If I wanted to I could run headers with 18" long turndowns off of them and even then the only thing I would have to worry about is the police.
i have a 1971 maverick.. and i had to get it emission tested every year in arizona lucky for me, the car never came with a cat.. otherwise i would have had to put one on.
Your carb is jetted ok and the engine seems to be in good shape. The hydrocarbons at idle are way high so you are either running real lean and the fuel is not burning well or your are running real rich. Check for vacuum leaks - use some WD40 and spray it on hoses, carb base plate,and around the manifold. Anyplace that the engine rpm picks up or drops there is a leak there. Fix it and go on. Advancing the timing over factory specs will help some cars but it can add to the HC levels if you go too far. Set the idle speed according to factory specs and then set the timing to factory specs. Using a tach get the mixture set to where it produces the highest idle. Now reset the speed with the idle stop screw. Readjust the mixture for the highest idle again. Keep repeating those two steps until you have the idle at factory specs and turning either mixture screw lowers the rpm. turn the mixture screws lean 1/8 turn. Lock it down with a little RTV. You will pass emissions. Stay away from alcohol or other gas additives because the gasoline already has alcohol in it for the winter months to make cars run leaner in the months that the choke is on for the longest (winter). That is a mandate from the Feds. It is 10% alcohol. if you add more and there is any water present it will precipitate the alcohol and water out of the gas. The alcohol and water will mix and sink to the bottom of your tank. when that mixture hits the pick-up and gets pulled into the carb it will feel like you are running out of gas. Its a nightmare. When it happened to me I was lucky my fuel tank had a drain so I just drained out the first gallon that came out of the tank and I got it out. The only other way to get it out if you don't have a drain is to pull the tank and clean it out. Don't add anything with ethanol, methanol, alcohol to your fuel.You can get the emissions down without it.
what worked for me.... empty the tank. put in 1 gallon of cheap regular and 2 bottles of drygas. since they don't test for voc i breezed through emmisions. of course, right after i passed, it was a tanks of super! regular burns faster than super so i know the gas would all burn off. of course, make sure the car is tuned up to factory specs. make sure thermostat is working right so you are running to normal temps. best of luck.
