• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 86 245 hall sensor voltage

All Volvo

New member
Joined
Apr 19, 2016
i am reading 1.88v at the middle terminal...is that too low?

when the key is turned the tach jumps and sticks up wavering slightly...ignition module or hall sensor issue?
 
DVOM won't test hall sensor accurately. Need scope.

Tach is likely the problem of your tach problems.
 
the volvo will not start...no spark. i tested the hall sensor and got just over 1.8 volt...hard to say if the hall sensor is the cause, if i had a spare unit that would help. even ignition module swap did not solve it. wiring looks good....
 
Dvom will average out the signal. Scope the pattern for a clean square wave to really tell. Dvom is the wrong tool for the job.


On a basic level I suggest just a test light the signal wire to the Chrysler box. Or again, even better scope it. Test light will go blink. Also could check coil negative for blinking on a test light may tell you something.


Forget 30 year old flow charts! Use modern tools and techniques!
 
Dvom will average out the signal. Scope the pattern for a clean square wave to really tell. Dvom is the wrong tool for the job.


On a basic level I suggest just a test light the signal wire to the Chrysler box. Or again, even better scope it. Test light will go blink. Also could check coil negative for blinking on a test light may tell you something.


Forget 30 year old flow charts! Use modern tools and techniques!

yeah i read the green book...like a comic book for us volvo guys.

i took the distributor out and checked the voltage with a 12v supply.
 
I have a scope, as most readers are aware, but I'd let it rest in this case and grab the 30-year-old flowchart. Reasoning is, the flowchart reminds me of which pin does what on the two dizzy configurations. And I know right where to find a paper clip in the garage.

But what is said next reminded me of another situation.

"Necessity is the mother of invention....A need or problem encourages creative efforts to meet the need or solve the problem. This saying appears in the dialogue Republic, by the ancient Greek philosopher Plato."

Problem: New found Volvo friend needs a distributor. It was 15 years ago, but I think the reason was the old crank with the cap off mangling. Regardless of the reason, I planned to stop by the junkyard during my lunch hour and try to find him one. Assuming I had a short opportunity, and getting them out was a lot of work, success would be more likely if I could be sure the Hall sensor worked before deciding to pull the dizzy.

If you rotate the crank until the vane is open at the sensor, a feeler gauge will activate it.

dist012.jpg


To test it in the pick'n'pull, I needed to supply power to the Hall sensor, and watch its response to a feeler gauge. I understand the pick'n'pulls don't like people testing the parts before selecting them, but that was the risk I took.

diag5142.jpg


Yes Kansas, sometimes ya need to be creative.
 
you guys are really great thanks!

perhaps there is still hope for turbobricks. HA!

i finally found the damn thing, yesterday i had two other cars so could not really focus, tested injectors and they were not firing...dead 2nd coil at Fuel Relay.

heh, i checked initially the relay for the click and left it at that...went over everything today. jeepers creepers.
 
Back
Top