Are there functional system descriptions e.g. idle available?
04-13-2016, 08:14 PM
#1
Rennlist Member
Thread Starter
Are there functional system descriptions e.g. idle available?
I've been on this forum for nearly 15 years and I've seen the same problems in multiple threads e.g. idling problems.
Usually the problems are solved but one thing that isn't addressed is how the system functions normally. I figure this would allow people to do more self problem solving if they knew what the critical functional points were.
Is there a source of normal system function descriptions out there? If not, can we use the collective wisdom to start threads describing the systems, particularly the common ones like idling.
In the case of idling this could cover the following:
How the engine ECU knows it is in idle mode (idle micro switch)
How the air is metered in idle mode (ISV)
How fuel is metered in idle mode?
The role of the ECU in idle mode and critical inputs e.g. crank ref sensor.
What is idle adaptation and how does it work?
What commonly goes wrong and how you test it?
The above is nowhere definitive but you get the idea. One source of truth.
Thoughts?
Usually the problems are solved but one thing that isn't addressed is how the system functions normally. I figure this would allow people to do more self problem solving if they knew what the critical functional points were.
Is there a source of normal system function descriptions out there? If not, can we use the collective wisdom to start threads describing the systems, particularly the common ones like idling.
In the case of idling this could cover the following:
How the engine ECU knows it is in idle mode (idle micro switch)
How the air is metered in idle mode (ISV)
How fuel is metered in idle mode?
The role of the ECU in idle mode and critical inputs e.g. crank ref sensor.
What is idle adaptation and how does it work?
What commonly goes wrong and how you test it?
The above is nowhere definitive but you get the idea. One source of truth.
Thoughts?
04-14-2016, 06:47 AM
#2
Three Wheelin'
I know it's not quite what you're asking but the factory manual has a reasonable diagnostic section. Volume 1, pages 192 through to 232 section 24/28.
It has a nice chart with common faults such as poor idle, hesitation, poor hot start etc, cross referenced with the systems implicated; idle switch, AFM, o2 sensor etc, and then details of the diagnoses and verification of each with a DMM.
It has a nice chart with common faults such as poor idle, hesitation, poor hot start etc, cross referenced with the systems implicated; idle switch, AFM, o2 sensor etc, and then details of the diagnoses and verification of each with a DMM.