I bought a 93 Volvo 240 a couple months ago. It was in running condition when I bought. It needed a new alternator a couple weeks in. More recently it has begun randomly losing power and idling roughly. My wife drove it for work today and had to pull over 5 times throughout the day. She’d wait five minutes to start it up and then she’d have 10 more miles or so out of it before it lost all power. So far I’ve replaced spark plugs and wires, cap and rotor, new fuel pump and filter, new air filter, ran fuel injector cleaner in the gas, I’ve cleaned the mass air flow sensor. Any ideas where I should be looking next? Thanks

 

Check your crank position sensor. It is located on the top of the bell housing where the engine and transmission are mated. It has a fat black coax type cable that runs to a connector on the firewall. If the insulation is cracked and/or flaking then it should be replaced. Many time they become intermittent before they fail hard.

Another typical problem can be the fuel pump relay. When going to start the car you should hear the fuel pump run for around 1 sec when you turn the key to the II position (no cranking). When the car stalls and will not start you can listen for the fuel pump. If it doesn't run for that 1 sec when the key is turned to the II position then you most likely need to replace the fuel pump relay.

 

Thanks! I will look into both of those. I’ve noticed the new pump I put in buzzing a fair bit. Is that a bad sign of something?

 

If your main pump is buzzing it may be a sign of a failed in-tank pump. Your car has two fuel pumps - one in the fuel tank and one main pump under the car on the left side. Here is a site that describes how to check out your fuel pumps:

In the Tank - 240 Volvo Tank Pump and Sender

With a failed in-tank pump your main pump has to work harder and will fail sooner. You also may see loss of power under heavy fuel consumption situations.

 

My guess would be a MAFS problem, cleaning it rarely works!

 

Would it be possible for the 25A Engine management control fuse to cause this issue?