940 LPT 2.3 problems starting in damp

[haymitch]

Going to give this a try soon (famous last words). I've not managed to look yet because work has been mental this month. It's amazing how time passes.

I think I've found the right sensor: http://www.skandix.de/en/spare-parts...black/1037368/

Interestingly, it's listed as the sensor for the dashboard, but yet it has the part number and description for the injection system It looks like the right one to me, could anyone confirm please? The part number, 1346030, matches another post on this forum about the temperature sensors: https://www.volvoforums.org.uk/archi.../t-282596.html so I'm 95% sure, but why are they saying its for the cockpit display?

[Laird Scooby]

Originally Posted by haymitch

Going to give this a try soon (famous last words). I've not managed to look yet because work has been mental this month. It's amazing how time passes.

I think I've found the right sensor: http://www.skandix.de/en/spare-parts...black/1037368/

Interestingly, it's listed as the sensor for the dashboard, but yet it has the part number and description for the injection system It looks like the right one to me, could anyone confirm please? The part number, 1346030, matches another post on this forum about the temperature sensors: https://www.volvoforums.org.uk/archi.../t-282596.html so I'm 95% sure, but why are they saying its for the cockpit display?

If you read further about the sensor on Skandix :

Sensor, Coolant temperature (Cockpit display) black
Volvo 200, 700, 900

Sensor function: for Injection system

Last line say it's the sensor for the injection system.

In other words, the one you want, Bosch number ending in 032 or 069. It also says a little further up :


additional info:

Sensor with Bosch end number 032 or 069 for LH Jetronik 2.4. 2-pin sensor with flat connectors.

The temperature sensor for the injection system is the rear one of the two temperature sensors. It is screwed into the cylinder head under the intake manifold, next to the oil trap. Can be replaced from the front with a 19mm open-end wrench without dismantling the intake manifold.


In short, yes, it's the right one.

I don't know why the Bosch ECU is so firkin fussy but thanks for finding that, i need to change mine again soon after using an aftermarket one - improved matters for a while but got a slightly unstable idle during warm-up - not a major problem, just annoying!

[haymitch]

No problem, thanks for confirming that it's the right one I'll post an update once I've switched out the sensor!

[haymitch]

I managed to change the coolant temperature sensor this morning. Everything is looking good so far. The warning code is gone, but perhaps only because I disconnected the battery. Would this clear the code from the ECU? I noticed that the 'other coolant temp sensor' for the guage looked brand new so I think the garage changed the wrong sensor, assumed that the sensor wasn't the issue, and then moved onto other things.

The car started and sounded much better, but the idle was still *slightly* lump at first. I think I will try and clean the engine grounds next to see if I can make things even better. I'm wondering whether the car likes the new bosch sensor but that the grounds are still iffy. Does anyone have any thoughts?

I got the sensor off using this method from youtube: https://www.youtube.com/watch?v=BLTISPGXPuY

The video is for the 240 and I think room is tighter in the 940 but it worked like a charm.

Thanks for all your help I need to check the car starts properly a few times but hopefully the problem won't recur and this is finally fixed!

[Laird Scooby]

Congratulations, you are now qualified in Volvo Gynacology!

Joking aside, if the gauge sensor (on the 'stat housing) looks new and the one you pulled from the side of the head looks old, i'd agree with your theory that the garage changed the wrong one - muppets!

Disconnecting the battery would indeed clear the fault codes from the ECU, as will removing fuse #1 for a minimum of 30 seconds.

The fact it was a bit lumpy for the first few seconds is encouraging, it means the sensor was telling the ECU the engine was cold and because it was a new value to the ECU (but more inkeeping with what the ECU would expect), the fuel trims would be a bit out - once you've driven a bit and had the engine throughly warm a few times, this should even up a bit and you may even find economy improves, possibly even the way it drives too.

While i agree that checking the earth connections on the engine/body/battery is a good idea for preventive maintenance, give it a week or two on the new sensor so everything has time to settle and run as it should (hopefully with correct cold starting) so if you happen to distrub something while doing the earths, it won't throw you a red herring in terms of future diagnosis.

One final thought - did you top up the coolant after changing the sensor?

[Stephen Edwin]

This sounds like good news!

Originally Posted by haymitch

I got the sensor off using this method from youtube: https://www.youtube.com/watch?v=BLTISPGXPuY

The video is for the 240 and I think room is tighter in the 940 but it worked like a charm.

Yes. And by the way, a long 3/8 extension, preferably one that locks on to the socket makes this job quite easy. For this job I use one of my favourite tools, a locking wobble extension.

It's one of many jobs where I am glad I use mainly 3/8 drive socketry. There is a wide range of socket sizes available and I don't often need a larger drive size. My 3/8 is backed up with a good 1/4 range, a little used 1/2 range and a few useful 3/4 sockets with a couple of magnificent handles.

Some garages regard 3/8 as a sort of "secret weapon".

When Snap-On introduced their Ferret 3/8 range they advertised heavily to the trade as to its virtues including good access to the job to be done.

I use a fair amount of Snap-On. Bought as and when I have found good prices. Especially sockets, one needs a good grip on the fixing.

I am confident that in due course my Snappy tools will have a good sale price so it is good value. Some things I do buy cheap including unbranded. But quality tool brands (CK also &c.) deliver what needs to be done, and often offer items that cheaper brands do not offer.

Other opinions and criteria are available re socketry.

.

[haymitch]

Good to hear that it should have sounded a bit lumpy - I’ll keep an eye on it over the next couple of journeys and hold off on the grounds.
I topped up coolant so all good there

Interestingly, the sensor I replaced was an FAE sensor which I suspect is the sensor that fixed the problem back in October time (another garage replaced it back then). I reckon that the sensor failed as I’ve done 5000 miles on the car since then and then the second garage replaced the wrong one - maybe another mark against using aftermarket sensors?

Stephen - I managed to do the job with a ½ socket - just. I’d definitely agree that the ¾ drive would’ve made it easier

[mocambique-amazone]

FAQ is waste, made in Italy and won't read right.
I did throw a lot into the garbage, got them from my supplier as OEM!
Haha, and another big mistake I did found: a 016 AMM with 007 internals. I did need a long time to find this fault.

If I remember right I did write above and at other threads: use only Bosch ones!
Not FAE
Not Marelli
Not Delco

Not BOSH ( realy : a Chinese copy, everything looks OK, but named as BOSH)

Good result and please have a word with the workshop, the reaction will present if they are worth to be visited again......., Kay

[Laird Scooby]

Originally Posted by mocambique-amazone

Good result and please have a word with the workshop, the reaction will present if they are worth to be visited again......., Kay

Let's be honest Kay - if they need the customers to tell them which sensor is which, they shouldn't be used again!

[atco]

Originally Posted by loki_the_glt

One thing to check is that the HT Lead is properly secured to the distributor cap, as it's in a really stupid place.

just pm you about the tool loki thanks