Volvo RWD 900 Forum

1994 944T 188K

Early in a drive yesterday the car just died at about 50 mph. Noticed the tach was reading zero as it coasted to a stop and then the dash lights came on. Thought it must be the RPM sensor. Swapped in a good RPM sensor and it would crank but not fire.

Noticed the fuel pumps would not cycle each time I turned on the ignition key- cycling about half the time. Wiggled the fuel injection relay and tried several more times resulting in an eventual start.

I took it out later in the day and pulled the fuel injection relay at highway speed resulting in immediate stall and tach to zero. Found that a zero reading on the tach (at least on these cars does not necessarily mean a bad RPM sensor).

Replaced the relay and continue on my drive. Shut the car off at destination and then experienced a no start situation. It made an effort once but acted like lack of fuel. Changed out the fuel injection relay, tapped the radio suppression relay, unplugged/plugged the AMM to no avail. Noticed again that the pumps did not cycle each time I turned on the key. Car finally started and I drove it home.

I am perplexed by the lack of consistent pump cycling with turning on the key. I am planning on looking at the relay socket for evidence of a bad female connector in the tray. I will also try another relay.

Has anyone else experienced a bad ignition switch with symptoms like this? There is no evidence that this is probable, but with intermittent problems everything is suspect. The action of the key seems fine and the dash lights are not suspicious.

I did not have a helper or a lot of tools either time it died yesterday. I will have a can of starting fluid handy for the inevitable “next time” as well as a socket to check the plugs for fuel. If I can get it to repeat the situation at home I will have a helper and I can check for spark.

Anybody have any other suggestions of some paths to chase down?

Thanks,

Randy