98 940 2.3lpt auto stalling, not starting

[zchael6]

Originally Posted by Laird Scooby

It's a possibility but you've also said it's often cut out when it's cold too. Worth checking this if only to eliminate it from the process.

If it's engine bay temperature it's more likely to be the ignition amplifier module as i think Ash mentioned when he was talking about the CPS further up.

The amp module is on an aluminium heatsink plate on the left hand inner wing behind the headlamp.

To help eliminate that from the proceedings, certainly on the hot problem, undo the two screws that secure the module to the heatsink and using a non-abrasive cleaner, clean the back of the module and the heatsink where the module mates to it and polsih them up as smooth as possible - don't use sandpaper or similar!

Once clean, add a smear of heatsink compound to the back of the module, as you refit it on the heatsink, give it a wiggle to spread the compound more evenly. Same procedure if you fit a new one.

Thing is, your warning lights only get their feed from one place and that's the ignition switch, although it does go through the fusebox to the instrument cluster/warning lights.
However the only thing that adds up if you lose the ignition and fuel as well as all dash lights/instruments is the ignition switch as it's the only common part.

Ok thanks for the advice. Right I’ve removed the ignition switch. The plug on the back of it was securely attached and took a good bit of force to pull off. The two flat head screws holding it on were only hand tight. I was able to remove them very easily. The switch itself came off and seems fine looking at it.

If I said it happens when the cars cold then that was a mistake. So far it has only happened when the car was hot.

Thanks!

[Laird Scooby]

Originally Posted by zchael6

Ok thanks for the advice. I can remove the ignition switch but is there any way of telling whether its faulty? Or is it just to remove in order to get the part number. I have spotted the ignition amplifier, I dont have any heat sink compound, would it still be worth removing it and cleaning the mating surfaces and reinstalling?

If I said it happens when the cars cold then that was a mistake. So far it has only happened when the car was hot.

Thanks!

Ignition switches are notoriously difficult to diagnose with heat-related problems, the usual test is substitution with a known good one. If you can get the part number and ensure the plug is refitted properly that's a step forward.

If it's purely heat related then definitely worth checking the ignition amp module and cleaning, if needs be order some heatsink compound from ebay :

https://www.ebay.co.uk/itm/Servisol-...D/361946013712

Not the cheapest but Servisol have been around a long time so they don't make carp! Keep the lid on when not in use (it can make a hell of a mess!) and massage the tube a bit before each use to make sure it's well mixed.

[zchael6]

Originally Posted by Laird Scooby

Ignition switches are notoriously difficult to diagnose with heat-related problems, the usual test is substitution with a known good one. If you can get the part number and ensure the plug is refitted properly that's a step forward.

If it's purely heat related then definitely worth checking the ignition amp module and cleaning, if needs be order some heatsink compound from ebay :

Thanks Dave for that advice. It definitely seems to happen after the car has run and the car only restarts when it’s cold again. I also should mention, if I do manage to get it going again when the problem is happening there does sometimes seem to be a relationship between the putting my foot down on the acceleration and it cutting out. Although it is prettty random

It’s starting fine now on the drive but it’s cold. I fear if I went out in it again after a short while it would start and then not stop till it cools down

Will

[Laird Scooby]

Originally Posted by zchael6

Thanks Dave for that advice. It definitely seems to happen after the car has run and the car only restarts when it’s cold again. I also should mention, if I do manage to get it going again when the problem is happening there does sometimes seem to be a relationship between the putting my foot down on the acceleration and it cutting out. Although it is prettty random

It’s starting fine now on the drive but it’s cold. I fear if I went out in it again after a short while it would start and then not stop till it cools down

Will

While you're waiting for the CPS, have a look at your fuse box, particularly fuses 11, 12 and 13 - pull each out in turn and inspect it for any signs it gets hot and likewise with the holders in the fusebox.

I can't remember exactly which fuse it is but i know at least one of those is associated with the fuel pump, in a 740 i had, one of the fuel pump fuses had been repalced with a separate fuseholder because it had got hot and caused the same cutting out problem, likewise with a previous 740 where i had to fit a replacement fuse holder.

[zchael6]

Originally Posted by Laird Scooby

While you're waiting for the CPS, have a look at your fuse box, particularly fuses 11, 12 and 13 - pull each out in turn and inspect it for any signs it gets hot and likewise with the holders in the fusebox.

I can't remember exactly which fuse it is but i know at least one of those is associated with the fuel pump, in a 740 i had, one of the fuel pump fuses had been repalced with a separate fuseholder because it had got hot and caused the same cutting out problem, likewise with a previous 740 where i had to fit a replacement fuse holder.

Hi Dave

Thanks for the tips. I’ve been in and checked the fuses and they don’t have corrosion and the box doesn’t show any sign of heating up.

I’ve been on a big trawling session through old threads reporting similar problems to which you and others have contributed lots of great advice some The same as in this thread. In one thread a member had similar Hot cut out issues and it was fixed by changing the fuel filter. I’ve looked under my car and the fuel filter looks very old so I’ll change that just to see if that helps.

This is the thread https://www.volvoforums.org.uk/showt...problem&page=8

[griston64]

at 154k your in tank pump might be dodgy as well. On a 98 car you only have the one pump in the tank. It's given away but a buzzing noise from the rear cargo area. Mine sounded like a Chinook helicopter

[zchael6]

Originally Posted by griston64

at 154k your in tank pump might be dodgy as well. On a 98 car you only have the one pump in the tank. It's given away but a buzzing noise from the rear cargo area. Mine sounded like a Chinook helicopter

The car sounds throaty but I put it down to the exhaust. I’ll have a listen tomorrow! Thanks!

[Laird Scooby]

Originally Posted by zchael6

The car sounds throaty but I put it down to the exhaust. I’ll have a listen tomorrow! Thanks!

The fuel tank is on the left so is far enough away from the exhaust that you'll hear the pump if it's noisy by laying on the ground with your head just forward of the rear wheel where the tank is.

https://www.rockauto.com/en/parts/au...fuel+pump,6256

That's an internal high pressure pump complete with strainer, there'll be Shipping & Handling on top and i'm not sure if they're sending stuff out at the moment because of CV-19.

Also because the Invoice Value of the part is over £15, expect to pay Import Duty of 20% plus £8 fee to Royal Mail for delivering a card telling you the exact amount. At 20%, the Import VAT is going to be about £4 - add on the £8 from the RM and it's nearer £12 just so you're aware.

[zchael6]

Originally Posted by Laird Scooby

The fuel tank is on the left so is far enough away from the exhaust that you'll hear the pump if it's noisy by laying on the ground with your head just forward of the rear wheel where the tank is.

https://www.rockauto.com/en/parts/au...fuel+pump,6256

That's an internal high pressure pump complete with strainer, there'll be Shipping & Handling on top and i'm not sure if they're sending stuff out at the moment because of CV-19.

Also because the Invoice Value of the part is over £15, expect to pay Import Duty of 20% plus £8 fee to Royal Mail for delivering a card telling you the exact amount. At 20%, the Import VAT is going to be about £4 - add on the £8 from the RM and it's nearer £12 just so you're aware.

That’s amazing the ones I saw on eBay were all £80! I’ll put in the other stuff I’ve ordered and see if the problem goes away! Problem is I’m worried about lengthy test drives during this lockdown period. Don’t want to get stranded. I guess with all this time on my hands and a cheap fuel pump available I might as well install a new one

[griston64]

You can get them in the UK FOR £13.99

https://www.autodoc.co.uk/car-parts/...r%5B0%5D=bosch

I bought a Bosch one for £90.00 the choice is yours

It's not a job you will want to do again in hurry !!!