The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Just failed emission test, now what do I do?

walker · 07-23-2005, 02:12 PM

Here are the numbers from my emissions test

loaded read loaded std idle read idle std
HC 115 450 180 450

CO 4.54 3.75 1.76 5.00

So, I passed on all but loaded CO, which I failed by 0.79. As it is right now it has a 1405 edelbrock, with one step leaner metering rods, initial timing at 5*btdc, total timing is about 24*ish, idle is at 750rpm, idle mixtures screws are set to lean best idle, new air filter, changed oil, I do have a pcv system (no more road draft tube). The test is a rolling at 34mph. I am running regular 87 octane fuel and did add a bottle of dry gas(isopropyl alcohol).
So what do I tinker with before I take it back, any suggestions would be greatly appreciated.
Thanks, Walker.

07-23-2005, 02:12 PM	#1
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	Just failed emission test, now what do I do? Here are the numbers from my emissions test loaded read loaded std idle read idle std HC 115 450 180 450 CO 4.54 3.75 1.76 5.00 So, I passed on all but loaded CO, which I failed by 0.79. As it is right now it has a 1405 edelbrock, with one step leaner metering rods, initial timing at 5btdc, total timing is about 24ish, idle is at 750rpm, idle mixtures screws are set to lean best idle, new air filter, changed oil, I do have a pcv system (no more road draft tube). The test is a rolling at 34mph. I am running regular 87 octane fuel and did add a bottle of dry gas(isopropyl alcohol). So what do I tinker with before I take it back, any suggestions would be greatly appreciated. Thanks, Walker. __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold