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E30 (1982 - 1993)
God's Chariot. The E30 was produced primarily from 1982 through 1991. The cabriolet was the one exception which was produced through 1993.

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Old 08-01-2013, 03:29 PM
15Michaeljoseph 15Michaeljoseph is offline
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Mein Auto: 1987 325is, 1997 328is
Question Running rich

So the m20 has been running rich for about 5 months, ever since i had it rebuilt due to a busted timing belt, and I thought it might be the t stat, but i did the pot of water test, and it works just fine. I went to the mechanic, who hooked her up for a pressure test, and found a leak in the radiator. $300 later, with new bmw radiator, It STILL RUNS RICH. I'm going to be pulling the cluster soon to do my odo gears, but A) if the ground nut was too lose or whatever, wouldn't it either be in the blue or in the red? and B) My gas seems to be disappearing quicker than normal, so I don't think it's that. Can anyone help? should I just replace the tstat even though i think it's okay?
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Old 08-01-2013, 08:48 PM
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hornhospital hornhospital is offline
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Re: Running rich

Why did you think that replacing the radiator would fix the too-rich running condition?

And I would suggest changing mechanics. If he hasn't figured out the rich running condition by now (he HAD to have noticed it when he replaced the radiator) he never will.

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Old 08-03-2013, 06:29 PM
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BigBoy740il BigBoy740il is offline
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Mein Auto: 1989 E30; 2000 E38; GS350
Re: Running rich

Why would he even lead you to believe that a bad thermostat or radiator would cause the bimmer run rich.... Too Cold or Hot maybe, but not rich. If the car temp is staying mid way on the guage you should eliminate that as a problem. Your problem is more a vacuum leak, bad 02 sensor, bad thermo temp sensor, dirty airflow meter, overdue tuneup, clogged air filter, bad fuel pressure regulator, leaking injector, leaking fuel lines..... As you see the list is enless, but a smart mechanic troubleshoots to fix your problem and not drain your wallet. My $.02

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Last edited by BigBoy740il; 08-03-2013 at 06:31 PM.
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Old 08-04-2013, 02:02 AM
Billwill Billwill is offline
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Mein Auto: BMW E30 318i 1991
How do you know it is running rich? Have you put an O2 meter on it?

There should be a screw on the AFM to adjust the O2 amount.this may not be there if you have a cat.
If the O2 value is way out then someone may have opens up the AFM and moved the large spring by one position which drasticaly changes the mixture.

If you do not find any other reason for this rich running then open the AFM and mark where the spring end is slotted in...moving the spring end one slot clockwise makes the mixture leaner; anti-clockwise makes it richer. This is a last resort...if the car had been running fine before then this spring should not have been moved.
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