Hey guys, I've got a question. My 05 mcs randomly gets a rough idle, usually for just a few seconds. Will do down, sounds like it's got a mild cam, then climb a little over 1000 rpm and then smooth back out. Can happen multiple times at a long red light, no codes. Has cheap plugs right now, msd coil and magnecor wires.

Also, anyone have experience with the old minimania plasma booster? P.O. installed it on mine, seems a little sketchy...

 

Get used to it. I think we/1st gen cars all have the issue. No rhyme or reason for it. Rev the engine a little and Motor On.

 

That's about what I figured lol. Hopefully someone will chime in on the plasma booster...

 

Mine does the same thing......don't think there is a "fix". Just rev the motor a little bit, and it goes away. It seems like a pretty common issue with our cars.

 

Mine does that too and would love to have that corrected.

 

Might be dirty fuel filter or fuel injectors. injectors have little filters in them that can get dirty. I had mine rebuilt awhile back, its inexpensive and makes them like new.


http://www.mrinjector.us/

 

Have a 2002 R50 second hand with 170500+ km on the clock, always had a rough idle, especially with the AC on. Added an injector cleaner and car went downhill after the tank was used. Changed the old style filter unit to the new style ($400) with paper cartridge thinking it was a duff filter, lasted for 100km and the issues started again. Car would idle inconsistent at traffic stops, then started to shut down completely at any speed resulting total loss of power requiring a restart. Fitted a new Fuel Pump ($375.00), fuel consumption has decreased from 7.9L/100KM to 6.2L/100KM, idle is now consistent with AC on or off. Old pump started to change pitch at idle (rear seat base removed to monitor pump sound after fitting new filter unit) from high to normal. Consistent with fuel supply problems, new pump has a nice steady constant pitch and car is running normally. Inconvenience during fault find was 2 weeks, parts were total of Australian $ 750.00, Labour was self, combined swap over time was 50 mins. If your filter is changeable, try a new filter, also listen to the pump and monitor it for a few days, if at idle, its changing pitch, its an indication your pumps on the way out which will cause fuel pressure issues and only gets worse. Be careful with fuel additives, they could end up being the last straw if your pumps getting old. Aside from the decrease in fuel consumption, the car is a lot more responsive. Its the same fuel pump and filter unit for the R53 and R52, pre 03/2002 models will need a whole new filter unit as the old tin can style are no longer in production and its a direct replacement that is standard in post 03/2002 models.

 

Milpol....it sounds like you've got some other issues going on.

The rough idle problem with the R53's......is only common with the R53's.....with a supercharger. It seems like everyone has had the rough idle issue ....sometimes it happens once a year, once a month, or once a week. It just idles rough for a few seconds, and then idles smooth again.

I've done everything you can think of to my car (plugs, wires, fuel filter, reset adaptations.....I still have the rough idle issue every now and then.

I think from what most people have said, it's just an issue with the ECM software....there is no real "Fix" for it. Even people that have aftermarket tunes for their R53 still have the issue.