Hi All

I've had problems with getting my Volvo 740 to start and I've been trying to remedy it. I recently put in a new ignition relay but alas that did not help. I've been told that I should try replacing the ignition control module and after finding an excellent video on Youtube I thought I'd have a go at it. The next step is to remove the Regina if that doesn't help but that is a last resort since it's difficult to find a replacement. I know the location of where the ignition contol module should be but there is nothing like that anywhere near there.

I'm including a few pictures of my engine and hopefully somepne will be able to help me with it? All help is greatly appriciated!


Engine left side

Engine right side

What is that rectangular metal housing on the left?

What is this? Sits over the front left wheel

The two black relays and the junction box on the left, what are they for? Is one relay for the fan?

 

Your ignition control module is part of the coil assembly, coil is mounted on top of it. Rectangular box next to the OBD port is the manifold pressure sensor. Regina cars use that and an air temp sensor in the intake hose as two of the parameters for mixture control. The black relays are used for various stuff on these cars, can be used for cooling fan, injectors, ignition, or maybe even that aux heater shown in the picture - depending on year and model. Those relays commonly get cracked solder connections preventing current flow, usually malfunctioning worse when hot under load.

Have you closely examined your cap, rotor and wires? And replaced the spark plugs? Do you have any codes stored in your OBD system? Is the speed sensor insulation in good condition, or relatively new? Those items might be a good first start after making sure any extra factory wires have a good connection at the positive battery terminal.

 

Your crankshaft position sensor would be the first thing I'd look at, then the fuel injection relay.

 

I've replaced the relay already but not the crankshaft sensor... Thanks!

 

By "ignition control module" do you mean the computer or the ignition amplifier? The computer on the these cars is rarely at fault, the amplifier shouldn't cause a no start.