Date: Sat, 18 Oct 2014 15:50:46 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Weird idle problem continues
In-Reply-To: <002301cfeb07$861b53b0$9251fb10$@gmail.com>
Content-Type: text/plain; charset="utf-8"
Where are you located again? Do you need me to fly there to fix it? Only kidding.
The hard start and idle problem is probably related. If it is flooding look at the Temp 2 sensor. The original sensors rarely go bad. What does go bad is the connector and the wiring to it. And then there is the ground connection for it. This sensor is used for both the ECU to control starting mixture, warm up mixture, when to go into O2 sensor operation and some ignition timing trim. It is also used by the idle stabilizer to modify idle speed for starting and warm up operation. There are also inputs for the AC and power steering.
The temps sensor gets a signal off of the ECU and sinks it to the chassis. As the sensor warms up the resistance goes down increasing current flow which reduces the voltage at the ECU. Any high resistance in this path leaves a high voltage making the ECU and idle control unit think it is like 40 below. Yes it will run rich and if it does run idle high.
Key on engine not running you can use a voltmeter to test the connections. On the ECU side of the sensor you need to see less than 5 volts connected, between the connector and chassis). On the ground side needs to be real close to "0" If you have voltage on both sides or much above "0" on the ground side you have a bad ground path. If 5 volts on one side then you have a bad connection to the sensor.
Hope this helps.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Stuart MacMillan
Sent: Saturday, October 18, 2014 3:13 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Weird idle problem continues
I would, but son is tapped out for now. Need to get a year or two out of this one!
From: Don Hanson [mailto:dhanson928@gmail.com]
Sent: Saturday, October 18, 2014 12:05 PM
To: Stuart MacMillan
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: Weird idle problem continues
Give in, Stuart....You know you are wanting a different motor...Do it now.
On Sat, Oct 18, 2014 at 12:02 PM, Stuart MacMillan <stuartmacm@gmail.com> wrote:
Okay,
Today it was very hard to start, much cranking with foot to floor to minimized flooding. Started, barely ran but 30 seconds later runs up to
3000 rpm and stays there. Warmed it up for a couple of minutes.
Unplugged O2, Temp2, and idle control power plug. Same hard to start condition, but it went to 2000 and stayed there. Checked the timing and it was a bit advanced but steady, so I adjusted that.
Hooked everything back up and still hard starting, but went right up to 3500 rpm. Gave up.
This is not a problem with the idle control circuit. What's left? AFM?
ECU? Other?
About ready to have it towed to a shop where they can substitute parts they have lying around, but that would be painful in so many ways.
Stuart