98 940 2.3lpt auto stalling, not starting

[Laird Scooby]

Sounds like you plan a marathon fitting session Will? If you do, fit one part at a time and carry the others (safely) in the car with the tools (if necessary) to fit them by the roadside, except of course the fuel pump - you'll need to do that at home i reckon.

The reason for one part at a time is you will then know exactly which one cured the problem.

[zchael6]

Originally Posted by Laird Scooby

Sounds like you plan a marathon fitting session Will? If you do, fit one part at a time and carry the others (safely) in the car with the tools (if necessary) to fit them by the roadside, except of course the fuel pump - you'll need to do that at home i reckon.

The reason for one part at a time is you will then know exactly which one cured the problem.

That’s a great idea. I’m just slightly worried about breaking down during this lockdown but yeah I’ll do the fuel pump and filter first and see how it goes with the relays and other parts in the car while I drive up and down the road! Thanks

[Laird Scooby]

Originally Posted by zchael6

That’s a great idea. I’m just slightly worried about breaking down during this lockdown but yeah I’ll do the fuel pump and filter first and see how it goes with the relays and other parts in the car while I drive up and down the road! Thanks

I'd start with the ignition amp module ......................................

[Rversteeg]

According an official Volvo publication:
In the last series 940 (1998) Volvo changed the type of fuel pump from a gear type to a turbine type. The pump is smaller and lighter.
This turbine type pump was also supplied as a spare part to replace the gear type pump and could be installed in MY95 and later by using a modification kit.

This seems to have solved the problem of failing fuel pumps. It is of course anecdotal evidence, but after over 400K miles my 98 LPT is still on its original fuel pump (turbine). Moreover it is an LPG car, so it is not uncommon that the pump is running for a long time at (very) low fuel level, a condition it was not designed for.

I noticed zchael6 also runs a 98 940, so presumably with a turbine type fuel pump as well. A failing fuel pump therefore seems less likely.

[zchael6]

Thanks for all the info about fuel pumps. I have to say my fuel pump seems to be making a pleasant, fast high pitched whine.

I have put the new ignition control module in. Cleaned the electrical contacts with wd40 specialist electrical contact cleaner

I’m sitting in the car with the engine running watching the engine come up to temp.


I have noticed the speedo hunting around slightly. It’s currently idling on or just under 750r/min. The needle only hunts very slightly. I’ll keep it running until it does or doesn’t cut out in which case the new ignition control module might have fixed everything

[Laird Scooby]

Originally Posted by zchael6

Thanks for all the info about fuel pumps. I have to say my fuel pump seems to be making a pleasant, fast high pitched whine.

I have put the new ignition control module in. Cleaned the electrical contacts with wd40 specialist electrical contact cleaner

I’m sitting in the car with the engine running watching the engine come up to temp.


I have noticed the speedo hunting around slightly. It’s currently idling on or just under 750r/min. The needle only hunts very slightly. I’ll keep it running until it does or doesn’t cut out in which case the new ignition control module might have fixed everything

Just so you're aware, what you've fitted is the ignition amplifier module - the ignition control module is in the drivers kick panel above/behind the ABS Control Module (ECU) both of which are above the fuel ECU which is usually closest to the floor behind the kick panel.

Hopefully it's fixed the problem, if it's already run longer than it previously did, there a good chance that was the fault. To prove it, you could refit the original and run it up again and see how long it takes before it fails.
Then refit the new one and if it starts and runs instantly, there's a very high chance that's the problem.

[zchael6]

Originally Posted by Laird Scooby

Just so you're aware, what you've fitted is the ignition amplifier module - the ignition control module is in the drivers kick panel above/behind the ABS Control Module (ECU) both of which are above the fuel ECU which is usually closest to the floor behind the kick panel.

Hopefully it's fixed the problem, if it's already run longer than it previously did, there a good chance that was the fault. To prove it, you could refit the original and run it up again and see how long it takes before it fails.
Then refit the new one and if it starts and runs instantly, there's a very high chance that's the problem.

Ok thanks! Well the car is still running on the drive. I have only driven it back and forth a bit on the drive. I feel like it might have fixed the problem and will reinstall the old one to check. I think it’s probably worth me installing the new CPS as the old one had a visible tear in the outer sheath

[Laird Scooby]

Originally Posted by zchael6

Ok thanks! Well the car is still running on the drive. I have only driven it back and forth a bit on the drive. I feel like it might have fixed the problem and will reinstall the old one to check. I think it’s probably worth me installing the new CPS as the old one had a visible tear in the outer sheath

Agreed on the installation of the CPS Will but wait until you've proved the old igntition amp is faulty as then you know you've got the problem fixed with the new one. Also let the engine cool down so you don't end up burning yourself on it while changing the CPS - it gets pretty warm back there!

[zchael6]

Originally Posted by Laird Scooby

Agreed on the installation of the CPS Will but wait until you've proved the old igntition amp is faulty as then you know you've got the problem fixed with the new one. Also let the engine cool down so you don't end up burning yourself on it while changing the CPS - it gets pretty warm back there!

Got the old one back in now waiting for it to warm up and See what happens!

Edit :

Right I’ve given the car a similar test, it’s nice and hot under the bonnet, been up and down the road in the car. And it hasn’t cut out with the old one in. I did clean the electrical contacts and also cleaned the mating surfaces of the amp and the heat sink on the old one. Could it be that that has sorted it? I haven’t been brave enough yet to take it on a big test drive . But it’s been up and down the lane and it’s hot enough under there that the fan is going

[Laird Scooby]

Originally Posted by zchael6

Got the old one back in now waiting for it to warm up and See what happens!

Edit :

Right I’ve given the car a similar test, it’s nice and hot under the bonnet, been up and down the road in the car. And it hasn’t cut out with the old one in. I did clean the electrical contacts and also cleaned the mating surfaces of the amp and the heat sink on the old one. Could it be that that has sorted it? I haven’t been brave enough yet to take it on a big test drive . But it’s been up and down the lane and it’s hot enough under there that the fan is going

Cleaning the mating surfaces, even without heatsink compuond has almost given you a respite. However, experience has taught me that once they get so hot the car cuts out (not just misfires), doing this is only a temporary solution.

With that in mind, i'd fit the new one and call it good, keep the old one in the car for a while as a temporary working one in case it happens again - if it's still on a heatsink you can simply swap the plugs over for instant diagnosis if it stops.