I have a 1993 Volvo 940 Turbo sedan which is loosing power to the injectors when it gets warm / hot.

Confirmed injectors are getting power and pulsing correctly until the motor warms up. The power fades and the engine gets flooded when the motor warms. I didn't meter the power but the light just goes dimmer and then nada. I can't restart the motor until the flooding clears up. I replaced the RSR (OEM) with no luck. The CPS, ECT and Fuel Pump relay along with the MAF (OEM) were replaced 6 months ago when the aftermarket MAF was acting up. I just replaced all the usual suspects as a precaution. Not sure where to go other than throwing an ECU at it but since it's a thermal problem (or at least it seems like), I'm not sure that's going to fix it.

Any ideas?

Thanks,
Rick

1993 Volvo 940T 153k
1994 Volvo 940 Wagon 134k
1993 Volvo 240 118k
1991 Volvo 240 183k

 

Are you aware of the noise suppression relay under the hood that supplies power to the injectors? Commonly solder joints crack and cause the injectors to stop working.
Resoldering or a new relay can solve that problem. Located under the hood near the power steering reservoir. Black relay with 4 round connectors.

 

Thanks for the input - it was the first thing I replaced since I thought it was a power issue. I call it the Radio Suppression Relay aka RSR but you're right it's the Noise Suppression Relay.