Frequency valve not buzzing 83'SC

[Vin-barrett]

Should jumping the terminals at the Lambda relay plug below give me 12 volts at the frequency valve connection?

It doesn't. Am I missing something?

[Vin-barrett]

bump.
JW? Warren?

[Gunter]

I seem to recall that the interior light fuse has something to do with powering the frequency valve.
Is your interior light working?

[Vin-barrett]

Yes , they work
5amp fuse for dome lights is good

[Vin-barrett]

Connector in the picture is where the relay plugs into.

[Scott R]

Originally posted by Vin-barrett
Connector in the picture is where the relay plugs into.

You're doing it correctly according to my wiring diagram. It should be pulsing with those pins jumped. Only thing I would add is that I would take a test light to powered terminal and make sure you have juice.

If it's the freq valve, PM me I have one you can have for the cost of shipping.

[Vin-barrett]

Thanks Scott. At this point I think problem should be something other than the frequency valve as I'm not getting power at the FV connector in the engine compartment (Lambda Brain?).

As a bit of added info I am doing this with engine running and I have juice at the connector.

[Scott R]

Originally posted by Vin-barrett
Thanks Scott. At this point I think problem should be something other than the frequency valve as I'm not getting power at the FV connector in the engine compartment (Lambda Brain?).

As a bit of added info I am doing this with engine running and I have juice at the connector.

Damn, yea at this point you have to track the power from the ECU pin to the large harness, looks like pin #8 and blk/red from the ECU connector. What I found on my first ECU wa that it had some cracked solder joints on the pins, it was an easy fix with the cover off.

[Vin-barrett]

I in fact do have about 8.5 volts going to one pin at the frequency valve connection, I put the other pin to ground- should have thought to do this yesterday.

so-

OK, it seems the Lambda brain may not be giving a ground to the other pin that would operate the frequency valve.

but- Is the FV doing what it's supposed to be doing when powered up?

I made a test connection shown here in the picture. When I put 12v to the FV all I get is one solid "click" nothing more. No buzzing/vibrating what-so-ever.



Is it a rapid "on and off" ground from the Lambda box that creates the normal buzzing or is there something wrong with my FV?

Can someone confirm this?
Scott- should I take you up on your generous offer?

Thanks
Vinny

[john walker's workshop]

the computer fluctuates the ground pulse, faster or slower, depending on info from the oxy sensor. if the sensor is unplugged, it still pulses, but the pulse doesn't vary. remove the computer, pull the cover and check for water damage or check all the solder connections with a magnifying glass. broken solder joints often show a crack as a circle in the joint.

[Scott R]

Originally posted by john walker's workshop
the computer fluctuates the ground pulse, faster or slower, depending on info from the oxy sensor. if the sensor is unplugged, it still pulses, but the pulse doesn't vary. remove the computer, pull the cover and check for water damage or check all the solder connections with a magnifying glass. broken solder joints often show a crack as a circle in the joint.

And that's exactly what was wrong with mine, broken solder traces. I used some freon I had to paint the joints nearest the terminal connector, it showed right away which were broken.

[Vin-barrett]

Thanks guys.
Looking at this, nothing is jumping out at me.

Does this look water damaged?

[Vin-barrett]

Is there a schematic of the circuit board of this componant anywhere online?
I have an electrical engineer at work I could have look at it

[Lorenfb]

Do a Google or a Yahoo search for "Lambda Control Unit".

[Vin-barrett]

Could the problem lie in the enrichment relay with the round plug that sits next to the Lambda brain?
If so how can I single out which componant is the problem?

I have stared at the circuit board of the Lambda brain for quite a while and see no broken solder joints.

[Scott R]

Originally posted by Vin-barrett
Could the problem lie in the enrichment relay with the round plug that sits next to the Lambda brain?
If so how can I single out which componant is the problem?

I have stared at the circuit board of the Lambda brain for quite a while and see no broken solder joints.

Are you getting power to the WUR and the AAR? if you are they are powered off the same relay.

[Vin-barrett]

I have not checked with a meter but car races when cold so I would say yes I do.

I have looked online at what these broken solder joints look like and can honestly say I see nothing like those examples.
Should I get a hold of a microscope?

[Vin-barrett]

update

I just swapped a known working Lambda brain into the car with absolutely no change. O2 sensor plugged in or not makes no difference

I still have 8.5 volts at one of the terminals at the frequency valve.

Not sure where to go from here I connected a fuel injector pulse tester like the one shown below



With this thing plugged in the car runs GREAT. Runs smooth with lots of power.
The terminal at this tool is about 12 volts and give the FV a very audible buzzing sound with vibration I could really feel.

Should I have a full 12 volts at the FV? Could this be the problem?

[Scott R]

Originally posted by Vin-barrett
update

I just swapped a known working Lambda brain into the car with absolutely no change. O2 sensor plugged in or not makes no difference

I still have 8.5 volts at one of the terminals at the frequency valve.

Not sure where to go from here I connected a fuel injector pulse tester like the one shown below



With this thing plugged in the car runs GREAT. Runs smooth with lots of power.
The terminal at this tool is about 12 volts and give the FV a very audible buzzing sound with vibration I could really feel.

Should I have a full 12 volts at the FV? Could this be the problem?

It was not 12V when I tested mine, I can tell you this because my PO had the plug for the WUR and the Freq valve switched and after a few days the valve melted and sprayed fuel everywhere...twice.

I'm not sure what it's supposed to be, I mean it's 12V but the ground is fluctuated to pulse the injector. It's not a constant 12 however. If I still had CIS I would be putting a meter on there right now for you.

All that aside, why not try an run a temporary line from the corresponding pins in the diagram to get around any electrical connection issues?

[Vin-barrett]

Hiya Scott

When I checked the voltage at the FV connector I am taking the pulsed ground out of the loop - correct?
In other words I put one probe of my meter to one of the FV connector's terminal and the other grounded right to the engine. This is where I am getting the 8.5 volts.

Like you said about a temporary line going around wiring issues.
I'm thinking running a long wire from terminal 87b at the relay under the seat straight to the FV to see if I get anything greater than the 8.5. I'm not sure what the voltage should be either.