Cold start stalling

[danmetallic]

Part of me is reluctant to post about this as this subject has been done to death, but I just can’t get to the bottom of it.

Basically our van stalls on start up and won’t hold idle until she is warmed up (by keeping the throttle down) for about 5 minutes.

Once warm she runs great and restarts fine.

This suddenly started to happen one very cold morning before christmas.

Starter, spark, coil dizzy etc are all fine. She basically starts on the nose with a bit of gas (and held down).

Thermostat housing has been replaced (this needed doing anyway), along with it’s two accompanying sensors. All connections cleaned.

Confident there is no vacuum leak or AFM issues.

I do have an additional sensor (see photo below) that has been installed by the coolant tank, no idea why, and it was done long before our ownership. When plug is disconnected and shorted I get an audible beep from the ECU.



Basically she appears to be not getting enough juice when cold and I need help!!!!

[silverbullet]

I am no expert, but going by what hasnt been changed:
Temp sensor in AFM (aka temp1) may be out of range or failed. Have you tried another AFM?

[bigherb]

Check the air bypass valve (idling stabilization valve) it might be clogged up so the disc is stuck closed, usually a good clean with carburetor cleaner works wonders.

[danmetallic]

Thanks chaps! While you're here am I correct in saying that the two temp sensors on the thermostat housing are the same part?

[bigherb]

Thanks chaps! While you're here am I correct in saying that the two temp sensors on the thermostat housing are the same part?

No they have different values. Blue for the engine ECU. Green or Black for the temperature gauge.

[danmetallic]

Thanks chaps! While you're here am I correct in saying that the two temp sensors on the thermostat housing are the same part?

No they have different values. Blue for the engine ECU. Green or Black for the temperature gauge.

I thought so. Well that explains the temp gauge up front reading incorrectly

Now just for the cold stalling.

[danmetallic]

Maybe nothing to do with warming up as she started up without having to today. Slight surge in revs after a few seconds then she held idle.

[danmetallic]

So the solution to this is still eluding me

Bypassed the Idle Stabilisation Unit (next to HALL unit), removed plugs and joined them together but still no joy. Idle Control Switch clicking in both positions. Buzzing coming from injector with ignition switched.

Not sure how to find, remove and clean (carb cleaner, I know that much) Idle Control Valve...so any pointers appreciated.

Also to elliminate potential problem with Idle Control Module (behind O/S rear light) can i just unplug this?

Thanks, Dan.

[jimrat]

Hi

I had similar problems last year (2.1 DJ), and found that checking/setting the ignition timing, and cleaning the terminals on the ISCU (small black box behind drivers side tail light) did the trick. If you google ISCU you will find some info on pin tests for the ISCU to test if it is working OK

Cheers
Jim

[danmetallic]

Hi

I had similar problems last year (2.1 DJ), and found that checking/setting the ignition timing, and cleaning the terminals on the ISCU (small black box behind drivers side tail light) did the trick. If you google ISCU you will find some info on pin tests for the ISCU to test if it is working OK

Cheers
Jim

Thanks Jim, I'm assuming you mean o/s tail light on a lhd? The ecu is on the drivers side

[jimrat]

Hi Dan

Same position as the main ECU, but on the opposite side of the engine bay (drivers side). It's hidden behind the plastic panel where the air intake duct attaches. It's a small black box the size of a pack of 20 cigarettes, and there are a whole bunch of wires which connect into it. The terminals get crusty, and the unit itself can fail.

Cheers
Jim

[danmetallic]

Hi Dan

Same position as the main ECU, but on the opposite side of the engine bay (drivers side). It's hidden behind the plastic panel where the air intake duct attaches. It's a small black box the size of a pack of 20 cigarettes, and there are a whole bunch of wires which connect into it. The terminals get crusty, and the unit itself can fail.

Cheers
Jim

Got you! Can the unit actually be bypassed like the Idle Stabilisation Unit by the coil. Or is there a way of testing it? I can find precious little information on this fella behind the tail light

And thank you!!

[jimrat]

Not sure about bypassing the ISCU. Seem to remember there being info on the US vanagon forums, or failing that, Bentley?

[danmetallic]

So the big relay behind the tail lights all checks out. Stabilisation valve is all good. Afm meter filter arrived today so will fit that when the rain stops.

[danmetallic]

Noticing some strangeness.

Afm plug has some weird going ons.
[img]//uploads.tapatalk-cdn.com/2016012 ... 0ecfc6.jpg[/img]

Yellow Connecter by ISCU appears to have an unconnected friend.
[img]//uploads.tapatalk-cdn.com/2016012 ... af5b64.jpg[/img]

And the as mentioned additional coolant sensor by the tank.
[img]//uploads.tapatalk-cdn.com/2016012 ... 3bd24b.jpg[/img]