| Author | Message | ||
| Lin Rating: N/A |
Is high idle a two cycle thing or do some 4's use it also? | ||
| Ron Walker (Prevost82)
Rating: N/A |
both...on a bus they use it for OTR A/C when parked..so the alt. will make enough amps to run the A/C | ||
| Lin Rating: N/A |
I thought that Detroits needed high idle to keep oil prssure up while sitting. | ||
| Brian Brown (Fishbowlbrian)
Rating: N/A |
FWIW, my Fishbowl doesn't have high idle and it doesn't have factory A/C. I'm not certain, but if it was truly about oil pressure, GM would have also probably put high idle on the transits w/o A/C. Just an observation. BB | ||
| Macgyver (91flyer)
Rating: N/A |
I've always heard that high idle keeps the temps up enough to keep carbon deposits from forming, and helps to blow off the deposits that may have already formed from low idle previously... On mine, I know that if I turn the A/C on, it idles up on its own, but if I put it in gear, it idles back down to normal, regardless of the idle selection. I'm assuming that this is to prevent lurching, as well as keep your foot from going numb holding that HEAVY air brake peddal.  Cheers! -Mac | ||
| Jim (Jim_in_california)
Rating: N/A |
Hippy buses often have high idle. | ||
| R. Steve Nichol (N4rsn)
Rating: N/A |
What do hippy buses use to get that high idle?? | ||
| R. Steve Nichol (N4rsn)
Rating: N/A |
You get high idle with a/c------- COOL | ||
| TWODOGS (Twodogs)
Rating: N/A |
so....whos got some a/c....& how do you roll it | ||
| John that newguy Rating: N/A |
Didn't Lola say you'd get higher idle with AC/DC? | ||
| TWODOGS (Twodogs)
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OHHHHHH LOLA she's been kinda quiet since hubby came home | ||
| Lin Rating: N/A |
Thanks, I guess that question was truly covered. | ||
| Buswarrior (Buswarrior)
Rating: N/A |
Hello some idle thoughts... High idle for a bus is/was for improving the performance of the air conditioner, both making enough electricity for all the fans, and running the compressor a little faster. Old and brand new, 2 stroke or 4, they all have a toggle switch to speed up the engine when parked. Pretty much everything else you've heard about high idle has been fabricated in fertile imaginations, or has been conjured up as some sort of questionable temporary compensating measure for some other underlying maintenance deficiency, that is on the verge of failure anyway. By design, high idle is interlocked with the parking brake and/or transmission to prevent its use while the vehicle is underway. Would be a bit hair raising to have the engine go to 1000 RPM as you pull up behind that squad car at the light, eh? happy coaching! buswarrior | ||
| Johnny Rating: N/A |
The fast-idle also prevents wet stacking. Many semis have it so the drivers can keep the heat or A/C on while sleeping without killing the rings. Any truck that uses hydraulics (dumper, trash truck, wrecker, tri-axle) or has a PTO pump (oil trucks) will probably have a fast-idle. | ||
| Brian (Bigbusguy)
Rating: N/A |
Even brand new trucks have a fast idle to ether keep heat when cold or help with a/c when hot. Most is run with the cruse control when parked . But the "wet stacking" was common with the older trucks not much a problem with the newer ones. The older trucks if left ideling a long time at a slow speed the unburned fuel would build up on the pistons and rings and wash the oil off the cylnder walls and get into the Oil. The only time I use fast idle is when warming up my bus or using the bus air for somthing . Brian 4905 Klamath Falls | ||
| Craig (Ceieio)
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I am amazed at all the interlocks on the systems in these old crates. Doing what they do with electronics seems doable to me but with air, solenoids, and who knows what else, they did some amazing things. The fast idle will not come on until there is enough air for the automatic belt tensioners (and I think the radiator shutters and blower venturi's) so the belts don't get blown off by too many rpm's. If you snick the Allison into drive, it turns off. If the parking brake is disengaged, it won't come on, even if you are standing on the service brake. Simple logic for digital circuits, but there are no digital circuits in my bus(well there are in the convection micro, but that doesn't count). Craig MC7 | ||
| Prather
Rating: N/A |
Actually the circuits are digital, 1 for on, 0 for off. Relays configurations are basic digital circuits. |