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Removed Smog pump - Great success but ques remain

Started by chinny4290, 11 April 2009, 02:04 AM


So I removed the smog/air pump and the contributing charcoal canister (got rid of the leaf blower sound oscar!)

So far so good. i just have to plug up the air lines in the carb but a few questions remain.

Before I removed the smog pump, I adjusted the ignition timing via pivoting the distributor (fiddled with it then put in a position that's slightly more clockwise than original position, don't know if that's retarding or advancing).

When I did that I was happy. No more misfires (it still needs valve adjustments), sounded better, ran better, idled better, and delivered power better and got MUCH better fuel economy (I run it on USDOT 89 Octane btw). There was a sputter in power delivery in WOT like misfiring but i cured it by doing the latter.

Now with the smog pump off, it idles just as well, but fuel economy went back down, and there are now sputters when doing WOT. they are subtle but you can feel it. It happens a couple times and doesnt bog down like a fuel delivery issue...I'd be doing WOT and i'd be accelerating but it would sputter but no real change in RPM.

Do I just have to plug up the two air lines on the front and back of the carb where the air lines went from the charcoal canister? Or would I have to play with the ignition timing again?

On another positive note, I sourced the coolant leak (many of you thought it was the steel line leading from the thermo to the carb). It was on that line but a metal clamp snapped from being completely rusted through. Just cured it with some zip ties until I get a new clamp. Hose is still soft and fresh.

Thanks guys!

1975 W116 280S - SOLD
1994 W124 E320 Coupe - Gone

CURRENT - 1974 450SEL