Volvo 940 Wanting to Cut Out on Startup in Mornings

[TonyS9]

Nothing wrong with have a few spares, but bear in mind the original factory fitted parts have a better pedigree than aftermarket parts, sometimes even OE from Volvo is not as good now as it was in the day. So leave them alone if all working.

Commonly failing parts to have spares:
Fuel pump Relay (Very important, almost certainly will fail eventually)
Fuel pump (will last only 100-200K miles, or a certain number of hours of operation)
Injection rail pressure regulator
Ignition amp
Crank sensor
Injector relay (radio interference suppression)
ECU temp sensor


Diagnosis tricks for no start
Listen for the fuel pump priming when the ignition is turned on (don't engage the starter). High pitch whine for about 1s. Later cars (96 on?) only prime once every 10s or so. Earlier ones every time ignition is turned on.
This means pump/relay is likely working.

Watch the rev counter while cranking. If not starting and no rev counter movement (small flicks) after a few seconds, then means no spark. Can be crank sensor or ignition amp. The ECU has to find TDC before firing up btw.

Also worth noting that no crank signal means no fuel pump (safety cut out).

[albertsmith]

Originally Posted by TonyS9

Nothing wrong with have a few spares, but bear in mind the original factory fitted parts have a better pedigree than aftermarket parts, sometimes even OE from Volvo is not as good now as it was in the day. So leave them alone if all working.

Commonly failing parts to have spares:
Fuel pump Relay (Very important, almost certainly will fail eventually)
Fuel pump (will last only 100-200K miles, or a certain number of hours of operation)
Injection rail pressure regulator
Ignition amp
Crank sensor
Injector relay (radio interference suppression)
ECU temp sensor




Diagnosis tricks for no start
Listen for the fuel pump priming when the ignition is turned on (don't engage the starter). High pitch whine for about 1s. Later cars (96 on?) only prime once every 10s or so. Earlier ones every time ignition is turned on.
This means pump/relay is likely working.

Watch the rev counter while cranking. If not starting and no rev counter movement (small flicks) after a few seconds, then means no spark. Can be crank sensor or ignition amp. The ECU has to find TDC before firing up btw.

Also worth noting that no crank signal means no fuel pump (safety cut out).

Thanks for the tips. Just found out from my hubby that the revs when cold are still below 1000 and it cut out once this morning, so he wasnt going to ring the guy who diagnosed it because he didnt tell him the problems leading up to the failure!

Told my husband to chat to the diagnostics guy again that this low revs and cutting out problem he has had since he bought the car but has done nothing about it. I nagged him again to talk to him otherwise we will be in same boat again in a few weeks.

Honestly hes hard work!

[Laird Scooby]

Originally Posted by albertsmith

Thanks for the tips. Just found out from my hubby that the revs when cold are still below 1000 and it cut out once this morning, so he wasnt going to ring the guy who diagnosed it because he didnt tell him the problems leading up to the failure!

Told my husband to chat to the diagnostics guy again that this low revs and cutting out problem he has had since he bought the car but has done nothing about it. I nagged him again to talk to him otherwise we will be in same boat again in a few weeks.

Honestly hes hard work!

How much below 1000rpm are the revs when cold and first started? Sounds like the AICV could do with a clean!

[TonyS9]

Originally Posted by albertsmith

Thanks for the tips. Just found out from my hubby that the revs when cold are still below 1000 and it cut out once this morning, so he wasnt going to ring the guy who diagnosed it because he didnt tell him the problems leading up to the failure!

Its a seperate problem, and I'd bet on the throttle body being too dirty.

Can of carb/intake cleaner is £5 from Halfords, but you do need to remove the throttle body and a gasket is a good idea to have. Its a 30min job.