95 940 Wagon (Black Betty) Died and no spark.

TWR1980 · Post by **TWR1980** » 17 Sep 2011, 17:28

I was driving to work last week and the car just went dead while I was putting along.

I thought I was out of gas like the last time it did this same death (gas gauge doesn't work). But I put 2 gallons of fuel in and still nothing. I call tow truck and he says, "car needs two things to start: fuel and fire." So he looks at things for a bit; tests to hear the fuel pump working in the tank, and says, "you got fuel in there."

Tow truck driver tested for spark (screwdriver method) and got nothing from plug wires or ignition coil wire. Ignition coil passes multimeter test, but I replaced anyway with a $5 junkyard swap that tested okay. Still nothing.

If there is no spark at the plug wire ends or at the ignition coil wire end and the ignition coil is testing okay, then what should I test next?

(It should be noted that I have not confirmed that there is no spark...I am trusting the tow truck driver who was very confident..."you got fuel in there but no fire.")

TWR1980 · Post by **TWR1980** » 17 Sep 2011, 18:24

Update: For the record it is too dark to continue tonight. I will pick up tomorrow following the steps listed here.

If anyone has any suggestions I am still all ears...thanks in advance.

Post by **billofdurham** » 18 Sep 2011, 13:43

Why are you using an 850 diagnostic sheet for a 940?

Have you checked for fault codes using the On-Board Diagnostic (OBD) unit? This is a first step in diagnosing these cars.

The screwdriver method isn't infallible. The best way to test for spark is to remove one plug lead and fit an old spark plug in it. Put the plug on the engine and crank it. You should see a big, blue spark. If that fails put the plug in the ignition coil output wire and do the same test. If that fails you need to be looking at the power stage.

Which system is on the car, Bosch or Regina? I noted that the tow truck driver listened to the in-tank pump but if it is the Bosch system there is another pump under the car. Regina only has the in-tank. Did he check that fuel was arriving at the engine? Crank the engine then remove a plug. If fuel is present the plug will be wet. If it is dry you have a fuel problem.

Another difference between the two systems is the location of the power stage. On the Bosch it is on the driver's side inner wing in the engine compartment. The Regina has the amplifier built in to the coil.

Do these basic checks and let us know the result. In the meantime I will sort out a trouble shooting guide for the 940.

Bill.

TWR1980 · Post by **TWR1980** » 18 Sep 2011, 23:51

Bill thanks for the response. You are one of the best resources available on this forum and I appreciate the help. I was resigned to take the car to a local volvo mechanic, but now I'm going to hold off for another day and see what I can find out tomorrow after work.

I have answered your questions below.

billofdurham wrote:Why are you using an 850 diagnostic sheet for a 940?

Because I didn't know anything about ignition systems and I figured I needed to start somewhere.

Have you checked for fault codes using the On-Board Diagnostic (OBD) unit? This is a first step in diagnosing these cars.

No. I will do this tomorrow.

Which system is on the car, Bosch or Regina? I noted that the tow truck driver listened to the in-tank pump but if it is the Bosch system there is another pump under the car. Regina only has the in-tank. Did he check that fuel was arriving at the engine? Crank the engine then remove a plug. If fuel is present the plug will be wet. If it is dry you have a fuel problem.

I have the cylinder shaped ignition coil. According to Chitlon, a Bosch EZK series ignition.. Tow truck driver did some stuff under the hood (I'm not sure what), to conclude that it is getting fuel. then he tested for spark at the plug wire end and the ignition coil wire end...and said I wasn't getting spark.

Bill.

Post by **billofdurham** » 19 Sep 2011, 13:21

Trouble shooting guide for 940 with Bosch system:

940 Basic Testing Non-turbo Bosch.pdf: (1.41 MiB) Downloaded 417 times

Bill.

JCosta · Post by **JCosta** » 22 Sep 2011, 07:42

I had the same no start problem, I'll pass on what I learned... Forums are great!

Check the engine speed sensor/impulse sensor i.e. (crank position sensor) located on top of the flywheel. Its easy to test the sensor, just follow the wire and disconnect the plug located on firewall. (mine was there) Test for proper resistance between pins 1 and 2. You should get around 180 ohms. When I tested mine I got 0 ohms and the wire shield was broken from leaning against the engine. Sensor was $38 at FCP.

Here is a link to my post and picture of the sensor.

https://www.matthewsvolvosite.com/forums ... =2&t=42671

Good luck...