Author Topic: Engine idles fast when you step on the break  (Read 4018 times)

jszeman1

  • Inactive
  • Silver
  • ****
  • USA, NY, Waterford
  • Posts: 259
Engine idles fast when you step on the break
« on: July 31, 2008, 06:18:16 »
I have an early 63 230sl.  When I down shift and step on the break to make a complete stope the engine revs higher. After 2 or 3 presses on the gas it stops but revs higher again when break applied.  A quick fix I hope?
JohnS

glennard

  • Guest
Re: Engine idles fast when you step on the break
« Reply #1 on: July 31, 2008, 07:53:54 »
Gotta leak from the brake booster into the intake manifold.  Also, sounds like you're running a rich idle.  (That's my first guess :?: )
« Last Edit: July 31, 2008, 19:37:38 by glennard »

Jonny B

  • Pagoda SL Board
  • Platinum
  • ******
  • USA, CA, San Marcos
  • Posts: 4198
Re: Engine idles fast when you step on the break
« Reply #2 on: July 31, 2008, 21:36:05 »
Try the search function with "brake booster leak" I got a single page of hits, and there were several there that look like they might be able to help you with the issue you describe.
Jonny B
1967 250 SL Auto, DB 568
1970 280 SL Auto, DB 904
1966 Morris Mini Minor

gugel

  • Full Member
  • Silver
  • ****
  • USA, CA, Rolling Hills Estates
  • Posts: 302
    • CPE Site
Re: Engine idles fast when you step on the break
« Reply #3 on: August 02, 2008, 13:01:00 »
As glennard says, you must have a leak from the brake booster into the intake manifold.  It could be the hose leading from the booster to the manifold, but IMO it's more likely that the brake booster needs rebuilding.  (A new one is very expensive, and doesn't look the same as the original).

Chris