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FB 12a Idles at 4000rpm with choke - Problem?

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Old 07-28-12, 03:44 PM
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FB 12a Idles at 4000rpm with choke - Problem?

I just test drove an '85 7 with a 12a. The car was near perfect for a 130k mi car. It was being sold by a Mazda dealer, so of course they want an arm and a leg for it, but that's another story.

When I started it cold w/ choke, it idled at 4k rpm. Is this normal? I thought it should be about 2k rpm. Also, I thought the choke was supposed to back off on it's own, but didn't after even after 5 minutes. Temp was up to 1/4ish on the gauge when I backed the choke off by hand. Then it idled at 800ish and ran great.

The only other problem I noticed with the car was the steering wheel had almost 2" of play when looking at the top of the wheel. It tracked straight and had no vibes up to 80mph. Normal steering wheel play or worn steering parts?

Thanks!
Old 07-30-12, 06:06 PM
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the choke idle speed varies depending on temperature, but you need to manually adjust it down to 2000 rpm after 15 seconds. (in the owners manual i gladly read) when it is cold outside my initial idle for my choke is about 3500 rpm. when it is hot, it is usually closer to 2500 rpm. it does not pull out as far during the summer either. the choke tries to adjust for best/easiest starting from what i understand. it should kick in not much after it passes the 1st thin line on the engine heat gauge. if it is not kicking in the autodisengage for the choke may need replaced. that could also cause it to not try to calibrate for the warmer/cooler temperatures.
Old 08-11-12, 07:31 PM
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GSL-SE 13b cold start question

Okay, separate question, on a different car. This is on a GSL-SE that my dad test drove for me. (close to him, 5 hours away from me). He said that when he started it and it was cold, it wanted to die when he tried to go. It was okay when warmed up.

To me, this seems normal for something with a carb + choke, but seems odd for a car with FI like this GSL-SE. Might there be something wrong, or is this normal?

Last edited by manofthefield; 08-11-12 at 07:33 PM.
Old 08-12-12, 01:12 PM
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just carry a can of starting fluid with you
Old 08-12-12, 08:19 PM
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i would not know for sure. i have never had the chance to work on a gsl-se, but there is equipment used to help it idle cold. many people remove the cold idle equipment because it is very expensive to replace if it goes bad and it really is not hard to deal with feathering the pedal until it warms up.

If you are looking at buying a 1st gen of any year, expect to put as much money as you spend on the car to get it running right. i spend 2k on my car and have put another 1k into the car with me doing all of my own work. They are all at least 27 years old so it will not be in perfect shape even if it has 10k miles on it. for instance mine had 74000 when i bought it and the problem is all of the rubber has deteriorated and due to not being driven often enough the needle valves started rusting. i also need a paint job which will be another hefty amount of money.
Old 08-13-12, 10:59 AM
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How much are you looking to spend? There are a few nice cars for sale in the GR area. Have you checked Craig's list?



.
Old 08-13-12, 11:10 AM
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Originally Posted by Kentetsu
How much are you looking to spend? There are a few nice cars for sale in the GR area. Have you checked Craig's list?

.

There's a GSL-SE over in Milwaukee that I'm getting serious about at a little over $5k. It's more than I was planning on but it is a GSL-SE and probably worth it.

I've been keeping an eye on the local craigslist. I've seen a couple cars, and talked to a couple people, but nothing has stood out for me.
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