CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
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Hi guys, I have adjusted the electric choke on my CCC carb to take about 4 minutes to completely pull off, per factory manual.
When the car is dead cold, I know I step on the gas once, which allows the choke flap to close, and also allows the tension of the choke's bimetal spring to ramp up the fast idle cam to the full fast idle position. When the car is cold it starts easy without having to hit the gas again.
Hot starts are the problem. If I shut the car off and immediately turn it back on, it restarts fine. However, if I shut the car off and come back 10-15 minutes later, and I hit the gas once before cranking, the electric choke bimetal spring has already cooled off enough to shut completely, and the engine nearly floods trying to start it. I notice that if I do not hit the gas once to do a 10-15 minute off time, still hot restart, the car starts fine.
Is it standard procedure, to NOT hit the gas once to let the choke come on, when the car is semi hot still?
I don't understand how the average person got around back when carburetors were the norm. Thank god for EFI!
__________________ 1989 Trans Am, 1979 Z28 w/ Holley Stealth ram and MAF '165 ECM, 1988 Chevy K1500 w/ L98 and TPI swap, 2003 Mercury Marauder, 2004 Taurus SEL
Ok thanks. I guess a heat choke would actually have an advantage over the electric choke in this aspect, that it would retain engine heat longer when shut down to more accurately reflect how much choke is needed on re-start
Huh, that's exactly what happens to me. Cold start is fine. "Warm" start - I just have to make sure I DON'T hit the gas, or else it will crank forever and I have to hold the gas to the floor and crank it over to let it clear it's throat. Nice black exhaust cloud to let everyone know I drive a beat up old Chevy
But without touching the gas it'll fire up perfectly.
I had your exact same symptoms and lived with it for a year and a half. Always careful not to give it gas or just enough when starting it hot. I replaced the distributor last Summer (along with all of my other ignition components) and it's like a different car.
The replacement was prompted by a rare, every few months or so, no start likely related to heat soak. The dist was the last piece I finally knuckled down and replaced (the PO had a receipt that it had been recently replaced). I suspect the choke/hot issue can be compounded by the weaker spark of an older, hot ignition system.
Now I can give it gas or not give it gas when starting warm and it starts right up-yes I've tested (but not like pumping it or anything, let's be reasonable). Just my experiences and certainly no recommendation to your situation or anything...
Interesting info NAF. I barely got to use my new coil/module that I dropped in my dist. maybe it has helped out. I'll remember to test that theory when I get all the pieces back together.
The only wear item in the dist., other than improper rotor to pickup gap or shaft slop, is the ignition module. I always see them missing in U pull it junkyards so it must be a high failure rate item. I have never had a hot "no start" condition, but I suppose a weak ignition module won't help anything. I will go ahead and replace it and check the coil out too and see if that makes any difference.
Ignition module didn't do it for me. I had replaced several of them, tried the generic AZ brand then ordered the AC Delco. I also replaced the usual items including coil/cap/rotor and re-did the short wire harness pieces chasing down my no-start. Ignition module is usually the prime candidate for a hot 'no start', one of the reasons it took me so long to go ahead and replace the dist.
'Bout once every six months or so I'd be stranded for about 45 minutes or so unless I opened up the cap and fiddled with stuff (probably helped cool it down-I'm sure now the fiddling had nothing to do with it).
The reluctor, or trigger wheel, will also get weak.
To address the original comment about the electric choke coil, things haven't changed that much - other than electric tends to be better than other methods. In the early days of automatic chokes, a tube was stuck into the exhaust manifold, with a tube going up to the choke thermostat. A small vaccum "leak" pulled air through those tubes, which was heated by the exhaust, which would heat the thermostat coil. Another version used a heated tube in the exhaust cross-over in the intake manifold. Point being that unless the engine was running, the choke thermostat would cool off, leading to "in between" issues that are hard to overcome.
EFI makes it much easier to accommodate all of these conditions.
The electric choke still cools off just as much during short starts, leading to too much choke w/ a fairly warm engine. I don't think it's any better than a remote heat choke, but a lot easier to disconnect.