Car won't start checklist....

[Semnoz]

and.....it's not starting again this morning....at all. So most probably not related to engine speed as it's turning quicker than before with this new battery.

[Splodger]

That's what I fear in the morning when I go to start the car now, fingers crossed all ok.

Hope you get it sorted for the hols.

[cheshired5]

Originally Posted by Semnoz

and.....it's not starting again this morning....at all. So most probably not related to engine speed as it's turning quicker than before with this new battery.

Capture the same data exactly as per the video.

[Semnoz]

Originally Posted by cheshired5

Capture the same data exactly as per the video.

I did set Torque logging for one of the [failed] attempts to start this morning. It's still configured the same as yesterday, so not setup as per the video, but I will do this eventually. The following is about 10 seconds of data, the relevant part being the 2 seconds between me pressing the Start button, and then off again:

[cheshired5]

Is there a particular reason why you don't do it the same as the video?
Coolant temperature is very important but missing and MAF is irrelevant but you include it.....

[Semnoz]

Originally Posted by cheshired5

Is there a particular reason why you don't do it the same as the video?
Coolant temperature is very important but missing and MAF is irrelevant but you include it.....

The only reason is that I quickly configured Torque after first trying it on my Focus, and haven't yet spent any time re-configuring it to make it useful for diagnosing this current fault on the Volvo. Just lack of time, that's all.

The SiRobb YouTube channel was already my reference point for all things accurate and helpful (I owe the author of those videos a big thanks already !), so I'm by no means ignoring the one related to using ODB/Torque to diagnose engine not starting - I'd not come across it until you referenced it yesterday.

RE: coolant temperature, I was viewing this in real-time when the engine started yesterday. I can confirm that it initially matched ambient temperature, and started to rise once the engine had started. I recall that it had reached about 88°C after I drove the car for about 5 minutes, and then it cooled down gradually after stopping the engine again once back home. I'll configure the app to log this as well.

thanks again

[Tatsfield]

Coolant temperature is of prime importance for starting the engine as it controls the "choke" function of the ECU's fueling regime. Without it the ECU doesn't know what fueling adjustments to make to enable the engine to run cold.

[Semnoz]

Originally Posted by Tatsfield

Coolant temperature is of prime importance for starting the engine as it controls the "choke" function of the ECU's fueling regime. Without it the ECU doesn't know what fueling adjustments to make to enable the engine to run cold.

That makes sense. When I back home after work, I'll have another go with Torque, this time logging coolant temp. Presumably I'm looking for an irregular value (e.g. way off ambient temp) or lack of value at all ?

However, if I have an intermittent fault with the coolant temp measurement, won't this have resulted in other problems, or error messages on the dash ?

Prior to this new issue of it not starting, there hadn't been a single issue, and no warning messages at all (for the time I've had the car at least).

I have another question, not about coolant temp, but related to fuel. I read somewhere that issues with the electronic fuel pump mainly manifest themselves with starting issues, and not once the engine is running as the mechanical fuel pump can pull enough diesel through on its own. And I guess the electronic pump could suddenly fail. I don't believe everything I read, but it might be valid ?

[tommyweaves]

I had a 2006 Passat that had in -tank fuel pump (lift pump). One day it wouldn't start but turned over as normal. AA chap came out to look and gave the fuel tank a thump. Then it started. Apparently the fuel pump sticks on its bearing before failing completely. A thump was enough to get it going.

So possibly worth looking into that?

[cheshired5]

Originally Posted by Semnoz

The SiRobb YouTube channel was already my reference point for all things accurate and helpful (I owe the author of those videos a big thanks already !)

In that case, your thanks are accepted.