Dwell at 60 all the time

[CFI]

https://www.youtube.com/watch?v=2sF4MU1txTY

You were measuring distributor dwell but talking about the O2 sensor & Lambda system? Those are completely disparate systems.

I know. I’m running several tests for different reasons. Sorry for the confusion

[CFI]

I think your lambda ECU is bad. From you past posts, it seems like something is pulling up the O2 input to the lambda. I have some extra lambda ECUs but it takes a medium flat rate box to ship it.

Thanks Dave. I’ll send a PM later today.

[Ron]

Is this my diagnostic plug? If so, what’s the purpose of the jumper wire?Attachment 59874

The whole plug used to go here (circled below in your pic from post 20):
Attachment 59893

Manuals use the jumper to bypass the connections going to an auto's neutral safety switch.

This chart should help:
http://dmctalk.org/showthread.php?16...326#post237326

[CFI]

The whole plug used to go here (circled below in your pic from post 20):
Attachment 59893

Manuals use the jumper to bypass the connections going to an auto's neutral safety switch.

This chart should help:
http://dmctalk.org/showthread.php?16...326#post237326

Thank you. I have the charts but can not find the diagnostic plug in my car. That red connector I’m holding was just sitting there near the bulkhead connectors. I’m guessing something was changed when the car was refurbished. I ended up using the orange wire on the blue bulkhead connector to get FV dwell.

[Bitsyncmaster]

Thank you. I have the charts but can not find the diagnostic plug in my car. That red connector I’m holding was just sitting there near the bulkhead connectors. I’m guessing something was changed when the car was refurbished. I ended up using the orange wire on the blue bulkhead connector to get FV dwell.

Diagnostic connector is down near the ignition distributor but the PO may have removed it. I removed mine since it has no use.

That red connector should have plugged into the red bulkhead connector but I guess the PO changed things.

[Ron]

Thank you. I have the charts but can not find the diagnostic plug in my car. That red connector I’m holding was just sitting there near the bulkhead connectors. I’m guessing something was changed when the car was refurbished. I ended up using the orange wire on the blue bulkhead connector to get FV dwell.

That's where I always get it...

Yeah, it does look like refurb/repairs -- For some reason the link to the pic of your connectors was bad in my post:

Post 20.jpg

[CFI]

Ok I’m back home and running some tests for a second time. I think I may have not had a good ground during the 1.5 volt test the first time, as I got a completely different result this time.

Hot engine:
O2 disconnected, FV dwell: 45 (book range 40-50)
Ground the O2 lead to ECU, dwell: 88 (book min 87)
1.5 volts applied to O2 ECU lead: dwell 12 (book max 20)
Reading from 02 sensor wire: steady at 1.0 (should be about .5 IIRC)

So it seems that my 02 sensor is reading high. I left the volt meter connected for a few minutes and it never really budged from 1.0 volts. Bad sensor?

Actually, now that I think about it the reading is probably correct as it represents a rich mixture. So maybe my mixture needs to be adjusted?

[CFI]

I plugged the O2 sensor in and ran some tests again

Hot engine

O2 volts fluctuating between .35 and .8
FV dwell fluctuating between 24 and 37

Also noticed the strong fuel smell is gone. It had been very strong even when the engine was hot.

I’m baffled. These current numbers look good. Perhaps something that is acting up intermittently.

[Bitsyncmaster]

I plugged the O2 sensor in and ran some tests again

Hot engine

O2 volts fluctuating between .35 and .8
FV dwell fluctuating between 24 and 37

Also noticed the strong fuel smell is gone. It had been very strong even when the engine was hot.

I’m baffled. These current numbers look good. Perhaps something that is acting up intermittently.

Your lambda is working so if the O2 sensor is good you should be OK. Mixture may need a little adjustment to get that dwell a little higher.

[CFI]

Your lambda is working so if the O2 sensor is good you should be OK. Mixture may need a little adjustment to get that dwell a little higher.

I guess I could try a new O2 sensor and see what happens, just in case that is what is acting up. With my luck the old one will be permanently rusted in place. If that doesn’t do it, I’ll have the Volvo guys down the road from me have a go.