What does the crank position sensor control on a 1985 240 with a four cylinder?

Looking at a car that has no power to the fuel injectors....It will run with starting fluid but dies when you stop spraying. 110+ psi fuel pressure to the rail so its definitely getting the fuel to the injector but they are not powering up for some reason.

I heard that the crank position sensor may have something to do with it since the fuel is getting there and there is a new injector relay as well.

Thoughts?

 

Your car does not have a CPS... It has a Hall Sensor which does pretty much the same thing as a CPS but is located in the distributor not on top of the bell housing. But better check your Radio Suppression Relay which sends impulses to the injectors. I am not sure where it is on a 240.

 

240s never had a Radio Suppression Relay. That is a feature of the 740s

The hall sensor is the thing to check. Without a signal from it the hall sensor, the computer will not fire the injectors. Do a search here on the site on hall sensor. You should find some posts on how to check it out.

 

No RSR in a 240? Did NOT know that!

 

O.K thanks....Its not my car, I'm just looking at one for sale that has the symptoms of a bad cps or hall sensor..... whichever it has. Its too nice of a car to scrap out....its in such great shape I'd hate to pass on it since it could be something so simple to fix.

So just replacing this hall sensor is easy as unplug and then plug and play?

 

It's not plug and run, but I think it's easy. It involves drilling out rivets and putting new ones in. Also you need to pop a light press fit pin out of the shaft to take the shaft apart.

Look here:
https://volvoforums.com/forum/volvo-...ed-help-38536/

In post #14 I have the Volvo manual's description of the process. The rest of the posts are good too. So have a look.

If the hall effect sensor is dead the tach will not register anything when the engine is cranking and you will not have spark (it may spark weakly twice, but it will not sputter at all). A bad hall effect sensor kills everything. It tells the computers to wake up and run the car. If it's bad the fuel pumps won't even fire up.

 

But on this car the fuel pumps are working and the car will start with starting fluid sprayed into the air intake....The injectors simply won't work for some reason.

Is the "hall sensor" a different name for the impulse injector sensor? This is located inside the distributor right?