PeachParts Mercedes-Benz Forum - View Single Post

pawoSD · #6 07-02-2009, 04:15 PM

Quote:

Originally Posted by MattBelliveau

Also, would vac leaks cause a higher or lower idle. I do notice that the transmission is shifting a bit firm...

The transmission should shift pretty firm, firm is better than soft. Vac leaks will raise the idle. On a throttled engine (gas) the more air it gets the higher it rev's.....that's why they have a throttle plate, it restricts air to the engine....the result is a vacuum in the intake....which is what the "economy gauge" is looking it, its essentially just showing the level of vacuum in the intake, black = high vacuum/low throttle, thus less fuel consumption, red is low vacuum/high throttle, lots of fuel consumption.

You can test for leaks by spritzing starter fluid around various spots on the engine while its running....if the rpms go up when you spray somewhere, there's a leak.