Bus Conversions dot Com Bulletin Board
July 23, 2014, 07:18:59 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: New ownership began September 1st 2012!  Please send any comments to info@busconversions.com
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: [1]   Go Down
  Print  
Author Topic: Fast Idle on MC 9 8V71 engine  (Read 701 times)
berrybus
Jr. Member
**
Offline Offline

Posts: 66




Ignore
« on: January 09, 2013, 06:15:59 PM »

We recently put on an air throttle and we relocated the shutoff cylinder.  Do we need to relocate the fast idle cylinder?  We do not have jake brakes. 
I guess my real question is just how important is the Fast Idle? Any suggestions?

Thanks again for any information!
Jim
Logged

"No man is a bus."
hargreaves
1987 MCI 102A3
Sr. Member
****
Offline Offline

Posts: 299





Ignore
« Reply #1 on: January 10, 2013, 02:04:36 PM »

Fast idle is mainly used for over the road A/C. It does help build air faster but thats no biggy.  Cheers Gerry.
Logged

now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia
bevans6
Hero Member
*****
Offline Offline

Posts: 4530


1980 MCI MC-5C




Ignore
« Reply #2 on: January 10, 2013, 02:05:21 PM »

It depends to some degree on where your fast idle cylinder is located.  Mine is part of the buffer screw (I do have jakes so there is also a jake switch in the deal) so it is completely separate from any other control on the governor like shut-down or throttle speed.  If you have it I would leave it.  It's main use is to speed the engine so that the OTR original air conditioning and heating system can run.  They draw too much current for the alternator to supply at low idle.  Without the AC, all I use mine for is to speed up the airing up process from a cold start.

Brian
Logged

1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Vintage race cars -
1978 Lola T440 Formula Ford
1972 NTM MK-4 B/SR
flynbanjo
Jr. Member
**
Offline Offline

Posts: 65





Ignore
« Reply #3 on: January 10, 2013, 06:05:37 PM »

The fast idle for diesel engines is used to keep the oil pressure up for extended idle times.  If you don't idle the engine for very long then it is not necessary to use.  If you intend to idle the engine for several minutes or longer then it would be necessary. 
Logged

Steven
81 MCI MC9
Hudson, Florida
lostagain
Hero Member
*****
Offline Offline

Posts: 1504


MC5C




Ignore
« Reply #4 on: January 10, 2013, 06:29:40 PM »

Yea, it is kind of nice to see some oil pressure at fast idle. I hate it when I see no pressure at slow idle when hot. I guess there has to be at least 8 psi, or the safety feature would shut it down, but still.

JC
Logged

JC
Invermere, BC
1977 MC5C, 6V92/HT740
TomC
Hero Member
*****
Offline Offline

Posts: 6667





Ignore
« Reply #5 on: January 10, 2013, 10:24:31 PM »

I took my fast idle out when I put in the Jake brake-chose not to use the very expensive double fast idle/Jake brake switch. I have a King Cruise control that works just fine as a fast idle. Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!