Cannot start my Volvo 940 2.3 Estate

[eternal optimist]

Originally Posted by aardvarkash10

you need a new garage guy.

This is a VERY simple engine. If it is getting fuel (yes) and has a spark (apparently) and has compression (any competent mechanic would have checked) it WILL start.

He is missing something obvious or is misled about what he is observing.

Agreed!

[David1956a]

Originally Posted by eternal optimist

Agreed!

Hi

Thanks to both of you

He said I do have compression so I will see what he has to say tomorrow

[Dippydog]

Not helping with your starting issue I know but I believe after the 900 series cars they changed to the S70/V70 and went to FWD or the AWD versions.By the way I live in the Ashby area of Scunny and have a phase1 V70 manual.

[Dippydog]

Hmmm, how odd in your signature I see you have the full spelling of town whereas in mine the 2nd,3rd,4th and 5th letters are replaced by asterisks!

[David1956a]

Originally Posted by Dippydog

Hmmm, how odd in your signature I see you have the full spelling of town whereas in mine the 2nd,3rd,4th and 5th letters are replaced by asterisks!

Hi

I only joined this forum last Friday so maybe the software has been up dated since you joined

What is AWD and FWD ?

[Dippydog]

FWD is front wheel drive[I believe the 900 series were RWD-rear wheel drive]AWD is all wheel drive with the cars being called XC70[I think that last bit is correct]

[Laird Scooby]

Get your garage to check the dizzy cap and rotor arm, especially the carbon brush in the dizzy cap. Amazingly i've known these cars still run without a carbon brush but starting was a problem!

It sound like they haven't done this yet or assumed they don't need to because a spark is reaching the plugs. However it's entirely possible that the spark they are seeing with the plug out is ok but not strong enough to fire when under compression.

In free air (in other words about 15psi pressure or 1 atmosphere) 25kV will happily jump a half-inch gap. Increase the pressure ten-fold to 150psi (typical compression pressure) and the same spark will struggle to jump 1/32" so might pay to check the plug gaps as well - should be 0.65 - 0.7mm (0.025 - 0.028") and maybe even stick a new set of plugs in it - correctly gapped of course!

While checking the ignition side of things, check the ignition amplifier module too, sometimes a failing one will go weak and deliver a spark to the plugs when they're out of the engine but not strong enough to jump the gap when they are in the engine.

Could be worth checking the idle control valve/auxiliary air valve, if it's not opening it won't provide fast idle so the engine will flood easily.

There has to be something that your guy has either misinterpreted or just plain missed. If the plugs are getting wet, then fuel is reaching the engine. That means either you have no spark in the cylinder or the fuel is poor quality - Easy-Start or similar may provide the answer to this.

[David1956a]

Originally Posted by Laird Scooby

Get your garage to check the dizzy cap and rotor arm, especially the carbon brush in the dizzy cap. Amazingly i've known these cars still run without a carbon brush but starting was a problem!

It sound like they haven't done this yet or assumed they don't need to because a spark is reaching the plugs. However it's entirely possible that the spark they are seeing with the plug out is ok but not strong enough to fire when under compression.

In free air (in other words about 15psi pressure or 1 atmosphere) 25kV will happily jump a half-inch gap. Increase the pressure ten-fold to 150psi (typical compression pressure) and the same spark will struggle to jump 1/32" so might pay to check the plug gaps as well - should be 0.65 - 0.7mm (0.025 - 0.028") and maybe even stick a new set of plugs in it - correctly gapped of course!

While checking the ignition side of things, check the ignition amplifier module too, sometimes a failing one will go weak and deliver a spark to the plugs when they're out of the engine but not strong enough to jump the gap when they are in the engine.

Could be worth checking the idle control valve/auxiliary air valve, if it's not opening it won't provide fast idle so the engine will flood easily.

There has to be something that your guy has either misinterpreted or just plain missed. If the plugs are getting wet, then fuel is reaching the engine. That means either you have no spark in the cylinder or the fuel is poor quality - Easy-Start or similar may provide the answer to this.

Many thanks for that - I will pass it on

[David1956a]

Again many thanks for all your ideas I passed them all to my garage car guy sadly he has tried them all - no joy

But he want to look again at the fuel pressure side of things this week

I have also talked to my local Volvo dealer as luck would have it 2 of the guys there have been in the game since the 940's were new and they were doing PDI's on them

They think they could sort it but no time till April so the car will stay where it is till then then it is off to the volvo dealer on a low loader and it will be time to start again

[Forrest]

I’m guessing most folk will have suggested things that have actually caused them problems in the past. There are a host of other potential issues covered in the FAQ. Maybe have a look at:

https://www.volvoclub.org.uk/faq/Eng...eSymptoms.html

and

https://www.volvoclub.org.uk/faq/Ele...lStarting.html

in particular.