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gebbiepress@pipeline.com

76 california car de-smog after effects

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1976 stock california car.

I have: removed and blocked off EGR and air pump systems, removed dashpot and "timer" box. White and red EM valves plugged and disabled. I have left the two relays (next to timer box) in place and have left adv. and ret. vacum lines to stock distributor as well as the black EM valve.. Other vac. lines plugged. Air pump removed, check valve plugged.

It seems to run rich at idle. Not a surpise, as there is no "after burner" effect due to lack of air injection and no dilution due to injected exhaust gas. However, my EGR was carbon deposit blocked, so this did not come into play.

I am a confessed neophyte, but all theory points to a richer idle once I did what I did. Should I, could I...somehow de-rich the idle? Moderate to small amount of black smoke from exhaust at idle.

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and if Weber, manual or automatic choke? Reason for asking about the choke: it may be not turning off all the way and causing a rich condition.

If it's the original Solex, they didn't do very well when new, and haven't improved with age. Most can be tuned to either run well when the auto choke is engaged, and then not idle well when warm, or vice-versa.

Let us know what you have carb-wise and more of the symptoms. And BTW, IIRC the entire emission system wiring harness can be unplugged from the car's main harness and removed, along with all the vacuum valves, etc to clean up the engine compartment considerably.

cheers

mike

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THANKS! It's the solex 2 barrel. Perhaps I'm lucky, or it's just that the car has only 40,000 original miles on it, but it ran perfectly before I started to "fix" it ;>)

So it has the water and elec. choke, idle shut off valve and thermostart valve.

What I did was to disable just one thing at a time and do a cold start, warmup and then test drive. I'd unplug the adv. to the diz, the ret. to the diz, this relay, that relay, all the various permutations, etc. and what I have left seems to be the best.

But am I at least correct in theory that minus the AIR injection, it should be running a tad rich at idle? I would then guess my next step would be to advance the static timing by a degree or three and see what that might do? From what little I know, the stock timing is quite late, the idea being to lower cylinder temps at idle and burn off the fuel in the exhaust manifold via the AIR system.

Oh, the only thing I notice is a mild amount of darker exhaust/less well burned fuel smell at idle.

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What I did was to disable just one thing at a time and do a cold start, warmup and then test drive. I'd unplug the adv. to the diz, the ret. to the diz, this relay, that relay, all the various permutations, etc. and what I have left seems to be the best.

* I'm no expert on 76s, but the setup is similar to the 72-74 plus an air pump. It seems to me that if you appropriately remove/unplug/plug all the add-on emission stuff, you'll be left with essentially a Euro setup. Don't think I'd disconnect the vacuum advance on the dizzy; the retard, yes, but not the advance. And I presume you also removed the throttle positioner--that vacuum capsule that keeps the throttle from snapping shut when you release the accelerator. It's bolted to the intake manifold and touches the throttle linkage.

But am I at least correct in theory that minus the AIR injection, it should be running a tad rich at idle?

* I think you're correct.

I would then guess my next step would be to advance the static timing by a degree or three and see what that might do?

* Yep, and you might check the primary barrel idle jet and see what size it is, the go down one size (i.e. if it's a 55, go to a 52.5 or 50). If you can't find Solex jets, lemme know, I may be able to help.

cheers

mike

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Guest Anonymous

California in 1976 was totally clueless and dangerous on smog. Still are! If you have the decal on the fender passenger side you should have tune settings. The co at idle with the air pump disconnected as I remember was an astounding 6%CO so the exhaust was set for producing a flame thrower in the exhaust manifold when the air pump pushed in extra air. Most smog techs just reduced the CO to avoid lean miss-fires. Of course this completely voided the airpump thing as the exhaust was too lean to sustain a flame and then the hydrocarbons wouldn't meet spec and bingo you lose.

Just lean out your idle so you get a solid non fluctuating rpm and be done with it. The heads weren't designed to idle well on a lean idle mixture and the stock ignition spark system didn't help.

Have fun

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