Hello, after driving about 10 minutes the 960 engine starts to lose power, it will start to run rough and then stop running altogether. It will not restart right away, it could be 15, 20, 30 minutes or more before it will start again, as if it needs a cool down. It is can be a little rough when restarting before hitting a steady rpm.

Some examples of behavior: 1) Driving on the freeway, traffic slows, I let up on the gas and that triggers rough running and engine failure within a matter of minutes. 2) Driving up a steady steep incline, engine is running strong, good rpm, then suddenly a quick power lose and shutdown occurs.

It has a new throttle sensor, ignition module, fuel pump relay, Mass Airflow Sensor, Fuel Pump (one by the fuel filter) and Fuel filter. Anyone ideas on what it could be?

 

What codes have you pulled?

Or there are two relays under the hood that power the injectors (2/12) and the coils (2/46) - could easily have a cracked solder joint in either one. There's power to both injectors and coils all the time when the car is running - and the control unit provides a ground to fire the coils and injectors when needed. There are 2 ignition modules on that engine - each fires three cylinders.

 

Hello Hoonk,
It wasn't pulling any codes during this power loss and failure to start. The problem was discovered it was the ECM - Electronic Control Module. I ordered a used one from ebay ($60 instead of $700 to $1000 new) it needed to be reset and reconfigured. Then the car started working just fine. That module was getting hot during operation and failing, that was the problem.

Also, I'm going to replace the idle control valve next. mechanic said so. Then look into what you suggested above. The mechanic went through a lot of stuff, checked everything said the car is in really good shape, that was nice to hear. Thanks for your input.

 

Hello!
So did you solve your issue with engine stops operating after ECM overheats?

 

It sounds like a crankshaft or camshaft position sensor problem that is overheating and causing the engine to stop. Check these sensors first, because their failure is common on Volvo 960s. 😊

 

Many thanks for that tip, will check it and back to inform if it helps

 

I found the problem, it was grounding wires. I spent about an hour looking for every possible wire I could find. I disconnected each one, shaved surfaces to fresh shiny metal and reconnected. There are two on the fuel injectors. The one near the battery going from the engine block to the frame was surprising. Half of the surface area on the frame was paint, not anymore. I also unclipped, blew out and reclipped all possible wire harness connections. Pay attention to the one down below in the back of the engine. Covered everyone with dielectric goop and bingo. Car runs better than ever, all 200 plus horses are running.