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crazy idle speed
Posted: 03 Dec 2005 04:43 pm
by white-wolf
Well after fitting in a MAF and a throtle butterfly from a 87 360 GLE, I was hoping to have again the normal runing engine. But no...
I saw the mainfold ( do not the exact word - the part where the butterfly swich is located ) was full of dirt mixed with oil. Nothing unexpected after runing high on fuel a long time. So i cleaned it with some carburator cleaner. After this, big surprize. I cannot set the idle speed under 1300 rpm. And this is with the idle swich fully closed ( clockwise ) and the co content swich almost out of its place ( almost maximum counter-clockwise ). The throtle butterfly is properly set ( rotated until it makes click, etc )
What could be wrong?
Should I change also the ECU? But I am talking about B200E on both cars...

Posted: 03 Dec 2005 05:28 pm
by RandomHero
You should change the adjustment of the throttle butterfly when the engine is running. Then you can set it the right way. Do it with the idle speed screw in the middle. Then you can always fine tune it. Then adjust the butterfly switch as it says in the manual and it should be OK.
The throttle butterfly adjustment must be set at 0.05 mm.
Posted: 03 Dec 2005 06:53 pm
by pettaw
yep, you need to set the adjustment of the big butterfly valve. you'll want it so you can JUST fit the tip of a 0.05mm feeler gauge into the gap. Reset the throttle butterfly switch so it clicks off at the right time etc and make sure the black connector onto the throttle spindle isn't pulling the throttle open constantly.
You should then be able to easily get the idle down to the correct level.
Posted: 04 Dec 2005 03:56 pm
by RandomHero
Just a quick question, i guess the idle speed can best be changed/set when the engine is hot and has run for a while?
Posted: 04 Dec 2005 05:30 pm
by classicswede
Yes it should be set when warm.
Posted: 04 Dec 2005 06:56 pm
by white-wolf
Well I did tuned the butterfly as it should be tuned from the first time but it did not work.
Today i have replaced the whole intake mainfold. I do not have words to describe how my engine runs now !
It is like listening to a cat purring.
Smth must have been wrong with my original one, thow everything looked ok
The only thing I spoted were 2 hoses mixed up ( atached to the intake is the GPL intake ) but I saw this after taking it out and I did not put it back, just replaced it with the spare one. Who knows maybe the 2 hoses were the problem. I will check it out later just to know. Anyways the plastic parts were kind of loose because smbody tried to tune it.
Bottom line - the engine runs very smooth, it responds much better to acceleration, I feel more power in it, the idle knob works fine and I hope to see improvement in fuel economy now.

Posted: 04 Dec 2005 08:20 pm
by classicswede
Do you have a picture of the GPL mixer you are useing, this is probable what the problem was. One pipe is for idle (air and fuel) and the other is for fuel only.
Dai
Posted: 08 Dec 2005 12:34 am
by white-wolf
No I do not have a picture. It is made in USA this I know for sure. I do not use the GPL thow and the mixer and tank are out my car.