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Discussion Starter #1
Hi everyone.

My 02 M5 has developed a mildly lumpy idle and sluggish throttle over the past while so as I'm doing some bodywork on the car, I'm going to get the injectors cleaned. It has 194,000 on the clock so no harm to clean.

I've searched and found many posts about injector cleaning but my only question is if I need to reset the adaptations after cleaning? I haven't connected the car to INPA to know what they are at currently.

Appreciate the help.

Thanks
Dan
 

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I don't believe that there is individual injector adaptations in e39m5, just overall fuel trims for each bank. Probably no harm in resetting that, but you can just do that by disconnecting the battery. You may be confusing injector adaptation on some of the direct injection cars, where each injector is uniquely calibrated.
 

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Discussion Starter #3
Cool. Thanks for the quick reply. I appreciate it.

The battery has been disconnected for 2 weeks now, and will be for another 2 at least while I get it ready for spraying. I think I'm suffering withdrawal symptoms already from not driving it :cry:!!

Will pull them out tomorrow and send off for cleaning.
 

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Whether you do anything or not is sort of moot. The car will adapt to the new condition of the injectors on it's own. That said those symptoms don't sound like injectors, sounds more like Vano's especially if the sluggish throttle is below 3500 rpm.
 

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Whether you do anything or not is sort of moot. The car will adapt to the new condition of the injectors on it's own. That said those symptoms don't sound like injectors, sounds more like Vano's especially if the sluggish throttle is below 3500 rpm.
Well just on this. There's a lag to the throttle throughout the whole rev range. A delay from pressing it until the engine reacts. It goes when the M button is pressed but the delay is more noticeable lately. I've checked the MAFs using the litres per hour test and they're fine. I also fitted new cam position sensors back in December. Does this still sound like a Vanos issue?

One thing it does too which maybe I should start a new thread for but the car gets a big boost of power once I go over 2000 rpm. You can feel a sudden surge. On the flip side though, engine braking seems very severe above 2000 rpm, but then you can feel it goes when below 2000 rpm. Almost like letting of the brake slightly! Any thoughts?

Even with all these 'quirks' I still love driving it.
 

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The first part does not sound like vanos because the vanos is working during the time when the car wants to return exhaust gases to the combustion chamber, so lower rpm. The main job of the vanos is EGR but there can be other advantages when you do things that way, so it gets complex. The second part definitively sounds like vanos because that is in the range where the car stops returning exhaust gas. It can be normally as high as 3000 rpm but 2000 is possible depending which of the solenoids is plugged up.
That said if the intake inlet vanos is very slow to react it might cause lag all the time. How dual vanos works is rarely described on BMW forums, but if you go to Honda forums/sites and read how their dual vanos works, it works the same and is well described. There are even sites and paged with great tech write ups on the system. V-tech.
 
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