Carburetor altitude adjusting

[C-Gaia]

Hey everyone,

I bought my '84 FJ60 from Denver which has an elevation of about 6000ft and drove it back to Providence, which is at sea level and the emissions failed because of the HC levels being too high.

I was thinking that the carburetor may need to be adjusted for the new altitude, but I'm not really sure, nor am I sure how to even do that so I can get a passing inspection.

The truck has a rebuilt 6 cyl with about 50K on it.

Thanks for any tips or advice.

 

[Cruisergreg]

Only adjustment is idle mixture, which is set at the factory and sealed. There is a small screw at the passenger side base of the carb. If you can see the screw it has been readjusted, if there is only a metal plug it's still got the factory setting.

Also check that the High Altitude Compensator isn't stuck in high altitude mode (ig timing will be at about 13 deg BTDC) from being in Denver 20 years.

 

[swank60]

Time to test everything in your emissions system. Do a search here, there's tons of info (God knows I've helped generate WAY too much of said info...)

As I understand it, your HCs won't be higher because of the altitude. If the carb was fiddled with at all for Denver, it would have been set up to run more lean, not rich.

Might be time to look at that smog pump and consider a repalcement, too. But get that FSM for the emissions and start going through everything - you might be surprised what you'll find.

 

[C-Gaia]

Thanks for the tips guys. Turned out to be a timing issue. All fixed now.