M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: SkidMark on September 11, 2014, 12:49:43 PM
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Well I have been chasing a 1222 lean/rich code om my e36 m42 powered race car for a while now and I finally solved it. It turned out to be the fuel tank purge valve was stuck open and allowing a massive vacume leak. It was kinda tricky to diagnose as the leak was the actual valve itself. It was doing what it is supposed to do, venting the tank, just not stopping when the dme told it to.. I remover the culprit and replaced it with a 1w 1k resistor to fool the dme so no check engine light. I then put a small fuel filter on the breather line and plugged the vac line..
Whala!! Car runs much better and no cel. Not sure if the e30 has this or a similar purge valve or not but e36 guys might want to check theirs. It wont throw a code unless the electric part of the valve goes bad. In my case the diaphram inside went bad causing a vac leak and no cel.....Skid ;D
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Nice work on tracking that down...thanks for sharing too. That's a very unexpected place for a leak!
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Whay symptoms were you having?
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There really aren't any symptoms with those 1222 codes. Most solutions don't work with these errors, they're usually very difficult to track down. In almost every case it isn't the O2 sensor at all. Usually it's a vac hose leak, weak gasket or a failed O2 heater.
The 1222 is just the DME saying the O2 is out of range, which doesn't mean a heck of a lot. If you have emissions testing in your area it's a real PITA.
I never noted any problems with the car running, except when descending really long downhill gradients in gear. I tend to use a lot of engine braking, and the car would start to run a bit rough in those cases. The CEL would flicker too, but it would magically clear up as soon as I got to level ground again.
I'm pretty sure mine was a bad air intake boot. The large ICV elbow was a bit loose. I'm not 100% sure because I replaced the boot along with all the hoses, the injectors and the intake gaskets. Happily, one of those items cured the problem and cleared the code.
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My car had idle issues and was running really rich... skid
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Does the e30 have this valve? if so where is it located? I am having similar issues with my car.
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There's two valves you should check. The E30 definitely has a purge valve solenoid. There's also a large one-way valve going to the brake booster.
Here's what the purge valve looks like:
http://picclick.com/BMW-E30-318i-M42-318iC-E32-735i-E34-170766578014.html
IIRC it's mounted under the intake manifold. It's connected between the charcoal canister and fuel tank breather line on the firewall.
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I think I have an injector leaking and this valve is bad also. Disconnect valve and car runs rich and no check engine light. Connect valve and bam...engine light comes on.