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930 Running Rich

I HAVE A 77 930 THAT IS RUNNING SUPER RICH. WHEN I PUNCH DOWN ALOT OF BLACK SMOKE FROM THE EXHAUST. I WAS ADVISED THAT IT COULD POSIBLE BE THE WARM UP REG WHICH I HAVE CHANGED AND STILL NO HELP. I HAVE TRIED TO ADJUST THE CIS AND NOW THE ENGINES RPM IS HUNTING (FROM 950-1400) CAN ANYONE HELP ME SEE SOME LIGHT THRU THE BLACK SMOKE.

Old 06-12-2003, 12:57 PM
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Welcome to the Board, now turn off the CAPS!

(I don't know how to help, I just couldn't stand the screaming.)
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Old 06-12-2003, 01:00 PM
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I see two rich symtoms. Black smoke and hunting idle.
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Old 06-12-2003, 01:03 PM
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ROBERT ANY SUGESTIONS ON CORRECTIONS
Old 06-12-2003, 01:13 PM
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Better let some of these better qualified turbo heads help you there. But I think leaning it out a bit might help. I run my 83 sc without 02 sensor and bump the mixture up a touch. It hunts for about the first 30 seconds when i start it cold, but then it settles down. Not sure on the 77 though.
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Old 06-12-2003, 02:00 PM
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It's the same thing, although, if you "adjusted" the mixture and it started hunting that means you went even richer. It's normal for a turbocharged engine with cis ( i think ) to blow a slight black smoke under initial boost. I'm told that the system under initial boost goes very rich and leans out a bit progressively until you hit the rev limit. I might be wrong though. But if your going to be adjusting a cis on a turbo, with high risk of detonation, i would use a co machine to make sure of your mixture so there are no expensive mistakes.
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Old 06-12-2003, 02:14 PM
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I'm no turbo expert yet, but I think it is much better for a turbo to run rich than to run lean. Mine will puff a bit under hard acceleration, and then runs perfectly fine. It should idle smoothly.
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Old 06-12-2003, 02:45 PM
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Get some pressure gauges and diagnos the problem. Turbos are not supposed to blow black smoke. If it is running too rich fuel gets past the rings and dilutes the oil.
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Old 06-12-2003, 03:25 PM
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Check sensor plate rest position.

Doug
75 911S
Old 06-12-2003, 04:11 PM
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thanks for all the advice i think my initial problem is at idle. it is almost imposible to stand by the exhaust because of it running so rich
any sugestions??????
Old 06-13-2003, 06:50 PM
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doug,
by the way would you happen to know where the sensor plate is positioned at idle?
Old 06-13-2003, 06:52 PM
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Lean out the mixture alittle
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Old 06-13-2003, 08:33 PM
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Everyone is "right on". Get a fuel pressure gauge (WUR check) on
the car and get access to a CO machine (mixture adj.).

Stop throwing "darts" to analyze the problem.

Good luck
Loren
Systemsc.com
Old 06-13-2003, 09:05 PM
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1) Lean the mixture.

2) Install an Andial Fuel Enrichment system so your mixture is "richened" while under heavy boost - prevents running too lean and melting pistons.
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Old 06-16-2003, 06:18 PM
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Quote:
Originally posted by BlkBird
. . Install an Andial Fuel Enrichment system so your mixture is "richened" while under heavy boost . .
My 930 used an andial enrichment system, but the controller pooped out a year or so ago so I went looking for replacements.

If you want a better way of enriching your fuel injection I recommend something like the following.

http://www.hksusa.com/products/?id=638

With CIS + AIC you have all the benefits of a mechanical injection system with a small piggybacked EFI system that allows you to tune the mix at different RPM and manifold pressure points.

Last edited by 350HP930; 06-16-2003 at 07:08 PM..
Old 06-16-2003, 06:58 PM
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Either a vacum/boost leak check all the connection to and from turbo to throttle body, check to see if your AIC is leaking. My SC turbo does the same thing when there's a leak in the pipe work.
Old 06-16-2003, 09:48 PM
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You don't give any background info on how the car ran before the rich condition started and / or what condition the engine is in.
If you have not tinkered with the CIS fuel enrichment screw then that should not be the problem. You should check all of the vitals first - to see where you are BEFORE you start fiddling. The CO should be set at 3%, the A/F ratio can be as high as 15:1 at idle and as low as 12:1 under full throttle. Fuel pressure should be set as per factory specs for your engine. Check for any plumbing leaks first. Changing the settings to compensate for an undetected leak will only complicate things. Get ahold of a set of factory manuals if you can or try out the schematics here on the Pelican site.
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Old 06-18-2003, 05:02 AM
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I have an 88 930 that is doing exactly the same as your 77, I am very interested to see if you fix your problem

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Old 08-02-2003, 11:04 PM
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