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-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   GSL-SE Idle/Cold Start Problem and exhaust leak (https://www.rx7club.com/1st-generation-specific-1979-1985-18/gsl-se-idle-cold-start-problem-exhaust-leak-1053012/)

LongDuck 03-24-15 04:27 PM

It's typical for the engine to run rich when started cold, and that's because it's effectively a choke mechanism and also a means of getting your catalytic converters up to operating temperature quickly.

The -SE has secondary throttle plates which are mounted in front of the true secondary butterfly valves which are CLOSED on cold start by the thermowax pellet and associated springs. Until the coolant heats up sufficiently and passes from the thermostate to the throttle body to the thermowax pellet - melting the wax - these secondary throttle plates are closed, inducing a rich mixture. Once hot coolant flows and melts the wax, internal springs allow the secondary throttle plates to open fully, thereby not restricting incoming air to the secondaries.

There's another thread on here about -SE throttle body swapping where we discussed this fully. Good luck, and that rich cold start idle is normal.

RX-7 Chris 03-25-15 10:08 AM

When I say smoke, I mean enough to make the car vanish in a cloud of gas fumes. Not the normal amount. I might have to take a picture the next time it does it.

One thing to note though is that the car hasn't done it the last two days. The amount of smoke has been normal.

I still need to figure out the idle. it is still idling too high, around 1000rpm.

NCross 03-28-15 07:50 PM

You need to check the return line for blockage and check the vent line for the charcoal canister for blockage. If the charcoal canister is clogged the fuel system will over pressurize and run rough at times.

RX-7 Chris 03-29-15 10:11 AM

I know for a fact we found out the charcoal canister is clogged. When we were messing with it a week ago, I pulled the hose off the canister and gas sprayed out of it. I've just left it off since then. Could that have been a big part of my problem?

Has anyone figured out how to rebuild the charcoal canister? I do know that you can put fish tank charcoal in it. How do you get it open though?

NCross 03-30-15 09:07 AM

Its a throw away deal.id keep it off. Blow through the vent an return lines with compressed air to clean them out. That will cause a huge problem. I had the vent line capped off once and a small clog in my return and the car went from idling like a bridgeport and overwhelming the floats to a normal idle after cleaning And uncapping.

RX-7 Chris 03-30-15 10:20 AM

I have an extra charcoal canister that is clogged that I may try and get open. I'm just a stickler for the details. I'll leave it off till I figure it out.


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