I have a 1993 940 Wagon (REGINA) and it is randomly dieing. When it dies, it completely dies. The service light is off once the car starts. It has died twice at a stop light, once going 70 mph, and once at 30 mph. I thought I had this fixed when I replaced my leaky exhaust manifold gaskets. I figured the O2 sensor was not picking up all the fumes and causing it to throw in more fuel loading it up. I am thinking maybe the radio suppression relay? Anything else that might cause this?

 

Crank Position Sensor, fuel pump relay, power stage...

 

Consider Fuel Pressure Regulator

 

Thanks, I will try those out. I have another 93 Volvo Sedan also Regina so I can just swap parts out and figure out if the issue stays with that car, or switches to the other.

 

Just replaced my fuel pump relay after having the same problem...no more stalling!

 

Well, I swapped out my fuel pump relay and the radio suppressor and it is doing the same thing. Now, I cannot get it started at all. The fuel pump does make a slight sound when I turn on the key and then quits (once it gets fuel pressure up) and when I try to start the car, I can feel the fuel pump relay click to turn the fuel pump back on to pump fuel as I am trying to start it, so with that info, I would think it is not fuel related. Looks like I will try the crank position sensor and power stage next.

 

Might be worth a try to take the voltage regulator off and check the brushes to see how they are wearing. Especially because it's free/easy. That was the cause of a similar problem for me about a year ago.

 

My money is on the CPS. Any update?

 

Sorry for the delay, I have to have the car towed home that day of my last post. The tow truck driver said he had a 740 that had a similar issue and had to replace the distributor cap. So I replaced it and the distributor rotor. The cap did have some oxidation on the leads inside the rotor (this car had the distributor on the block, and not the cam). We will see how this goes, maybe it just needed a tune-up. Went ahead and did the spark plugs too.

I am pretty sure the charging system is good as I have been able to crank the car when it dies, but just does not always start. I also remembered that when the car died at 70 MPH and the transmission was still engage thus turning the engine, the tach was showing 2,500 RPM and slowing, so pretty sure the crank positioning sensor is good since it runs off of that from my understanding.

 

Hmmm...pretty sure the tach runs off of the pulse generated on the neg terminal of the coil. That's how Bosch LH2.4 works ...I think Regina is the same but could be wrong...

 

Looks like you are probably correct. I know on older vehicles the tach gets its signal from the coil, but I think I miss read the Volvo Maintenance site. I figured since it has a crank sensor, just get the signal from that instead. In looking at the wiring diagram, there is a wire off the coil that goes to the instrument panel. After reading more, I think you are right though. I will put this next on my list to do.

 

Update: So, I swapped out the crank sensor and it still dies. I have a spark tester and I cannot see that I am getting any spark, so I think it is now the coil, so I will swap it out next and see if that does it.

 

Last update - It was the coil. Thanks for all your help. So many things on these cars that can cause this issue, but glad I have another 93 940 car to swap parts with to isolate the issue without wasting money on parts that did not need to be replaced.