question for all fi bikes

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Apr 21, 2006 | 10:26 PM

#11

FreddyP

Tourer

Joined: Sep 2005

Posts: 476

Likes: 41

From: Sin City

RE: question for all fi bikes

Have a 2003 EG stock 88 with EFI. Installed a Stage 1 intake, Power Commander III, flashed ECM for rev limiter (yes, this was before PC came out with their Rev XTEND), and a set of Hooker slip ons. Dyno tuned and idle ran solid 1000 RPM all of last year. Had the shop put a set of 203 cams in this winter and dyno tune again with custom MAP. I have noticed that bike idles around 1100 RPM on warm up then normally settles down to 1000 RPM. However, for the past week or so the idle drops to 800 RPM (once even down to 500 RPM) when I come to a stop after running for a 10 mile stretch on the highway. Took it to the shop today and they don't have an answer for the erratic idle. They think it might, might be temperature related....I'm running in 20 to 30 degree F temps here in Alaska. I don't expect the 203's to be quite as smooth as stock, but shouldn't the idle be more stable? Any ideas? Thanks!

Apr 21, 2006 | 10:32 PM

#12

Shovelhead Bob

Outstanding HDF Member

Joined: Apr 2006

Posts: 2,537

Likes: 21

RE: question for all fi bikes

IAC could be failing..... Or the roller bearing on the IAC Arm is not lubed....

The bad thing is that the PC Covers up a lot of the signs for it, as well as the DTC's that the ECM will generate when it encounters an anomoly...

That is the biggest fault with PC's....

Apr 22, 2006 | 12:06 AM

#13

springer_

Road Captain

Joined: Sep 2005

Posts: 583

Likes: 5

From: Maine

RE: question for all fi bikes

The idle is adjusted based on a MAP in the ECM. As the head temp changes, the idle is changed. With a carburated bike, you do this manually with the choke or enricher when the bike is cold. As the engine warms up, you turn off the choke. Since there is no choke or enricher, the ECM has to control it. The ECM sets the idle higher to keep the bike running as it warms up. The ECM also uses the idle to help reduce the temperature of the engine if it too hot. By reducing the idle, it generates less heat.

The idle is not to keep the battery charged or because of low oil pressure. The idle is kept up because a low idle hammers the lower end bearings. ALL Harley's are subject to this and the lower and "cooler" sound is doing damage.

Here is an example of the Idle Control Map in the ECM. With the SERT you can change these numbers but I wouldn't recommend it. This may be a Modified MAP and may not necessarily represent the actual numbers in a stock MAP.

Apr 22, 2006 | 01:27 AM

#14

seeg2005

Advanced

Joined: Nov 2005

Posts: 69

Likes: 0

From:

RE: question for all fi bikes

Just had my heads shaved and 258 cams installed. They lowered the idle from 1000 to 850. Sounds much better! More like a Harley!

Apr 22, 2006 | 10:51 AM

#15

claydbal

Cruiser

Joined: Dec 2005

Posts: 242

Likes: 0

From:

RE: question for all fi bikes

1040 rpm, with a little more fuel added at low speed.

would rather my bike run cool and not self destruct than to SOUND COOL.

Apr 22, 2006 | 10:55 AM

#16

chopperchuck

Cruiser

Joined: Feb 2006

Posts: 123

Likes: 0

From:

RE: question for all fi bikes

set the idle down to 800.. it won't hurt it a bit..don't listen to the scare tactics, if something happens to the motor because of a low idle then send the bill to me...i'll pay it. i've been running my harleys so low they will barely run for years and years...i don't have to change the batteries every two years and my motors are all high mileage..

Apr 22, 2006 | 11:02 AM

#17

Terry TK

Big Kahuna HDF Member

Joined: Feb 2005

Posts: 20,310

Likes: 160

From: San Antonio Texas

RE: question for all fi bikes

You are never going to get the old shovelhead lope on a twin cam anyway. I'm sure that the MoCo has the idle set at 1000 for a reason. Everyone has their own opinion on oil, pipes, tuners and idle speed. If your bike idles good at 800, holds oil pressure and charges the battery then that's great. If not. leave it at the factory setting.

Apr 22, 2006 | 12:17 PM

#18

springer_

Road Captain

Joined: Sep 2005

Posts: 583

Likes: 5

From: Maine

RE: question for all fi bikes

Quote:

ORIGINAL: chopperchuck

set the idle down to 800.. it won't hurt it a bit..don't listen to the scare tactics, if something happens to the motor because of a low idle then send the bill to me...i'll pay it. i've been running my harleys so low they will barely run for years and years...i don't have to change the batteries every two years and my motors are all high mileage..

Will you pay my bill too?? I can send it anytime. I can include the parts also if you want something for the money. They include a crank pin, bearings and rods. About $300 in parts and a complete teardown of the engine ... about $1200 should cover it. Of course in a twin cam, you have to replace the entire flywheel assembly, considerably more costly.

I just need a name and address and they will be on their way, I will include who to make the check out to also. Let me know ...

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