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Author Topic: Running Rich  (Read 1485 times)

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Offline siguy8

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Running Rich
« on: January 22, 2012, 03:43:15 PM »
I asked these questions in a few other topics, but I thought I'd start my own so I can be more specific and not hijack some else's.

My SX/4 is running rich. The exhaust smells like unburnt gas, and it's getting poor gas mileage (20 mpg instead of 30 that the previous owner said it used to get). It's an '82 with the Iron Duke. I've got a Holley Red electric inline pump mounted on the front of the gas tank. The previous owner put a cheaper one on, but it burn out (as well as another cheap one), so I put this one in. The Holley Red puts out 7psi and 97 GPH. The TSM says the SX/4 is supposed to have 6.5-8 psi and 1 pint per 30 seconds (converts to 15 GPH). So... I would guess that the excessive flow is causing my problems.

Can I control excessive flow rates with adjusting the carb, or do I need some sort of restriction on the pump (or even a different pump)?

Also, I have a new mechanical pump I am thinking about putting in. I'd rather not since it's a big deal on the Iron Duke SX/4 but, if I'm going to put it in, how do I "un-delete" the mechanical pump and re-route everything to the original set up?

Thanks for reading.
1982 SX/4 Sport 4 cylinder 5 speed manual. 135k miles.

Offline carnuck

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Re: Running Rich
« Reply #1 on: January 23, 2012, 12:12:22 PM »
I would try a fuel pressure regulator first. That carb should only have 4.5 to 6 psi or the needle and seat are forced open.
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Offline Sunny

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Re: Running Rich
« Reply #2 on: January 23, 2012, 03:35:34 PM »
I would try a fuel pressure regulator first. That carb should only have 4.5 to 6 psi or the needle and seat are forced open.

This^. A regulator will probably solve your problems.

Offline siguy8

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Re: Running Rich
« Reply #3 on: January 29, 2012, 12:19:10 PM »
Alrighty! I've got the regulator and hopefully I'll get it in today. Thanks for the advice.
1982 SX/4 Sport 4 cylinder 5 speed manual. 135k miles.