V6 Idle / Spark

[dn010]

#12548

I am sure this is a long shot as there does not seem to be very much information out there regarding these engines. I have a bunch of different books and nothing gives me any info on these areas…

Does anyone have any information on the large black adjustment screw located on the underside of the throttle body of the B280F engine? Is this what is used to adjust for CO content? I know it bypasses the idle motor and lets more or less air into the intake and this screw is set from factory but mine has been tampered with and I’m having a stumble at low RPMS I wonder if is related.

Timing, I know at idle it is 16 degrees BTDC. Does anyone have any timing curves?

[dn010]

#12549

Well, now that I’ve posted this, I found the idle speed setting procedure with this screw and also learned that CO is adjusted at the mass air sensor!

[Davies]

#12589

Thanks for letting us know what you found.  Please post any other details. Thanks Dan

[dn010]

#12593

Here is the idle setting details per my Volvo 700 series repair book and it can even be found online – I guess I just did not look hard enough prior to posting the question. It states:

Ground the CIS test point which is the red/white wire in the two wire connection located across from AC compressor. Doing this will move the air valve to the wide open position. Using the black plastic idle screw, adjust the idle to 700RPMs. Disconnect the ground wire from the test point and the idle should move to 750RPM.

 

So there is the solution to my idle question and idle adjustment. I adjusted my idle this weekend and found excellent results.

Now, I’m onto the hunt for an ignition curve, I’m interested in seeing what it looks like for the US 780 V6. I will let you guys know what I find, IF such information is even out there.

 

 

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