Volvo 480 Club Europe

Hi, I'm Ben. I'm new. Have a 480 ES 1.7 1992

So I was waiting a while for a new thermostat housing and the 480 had sat there for a while. Finally fitted the part, car started fine, bled fine, topped up coolant and all was good.

Then I went to drive it and the revs start stuttering and falling and she cuts out. Then she struggles to start at all.

I've checked for air leaks and there's nothing obvious. I've taken the crank position sensor off and cleaned that. She then started fine from cold again and once up to about 88 degrees, started stuttering and stalled again. Then wouldn't start.

The idle control valve is new, so is the throttle position sensor.

All I can think of is a temp sensor and aparently there's 3? one for ECU and one for the Info Centre and another?

Any help would be great.

Fanks

Hi Ben, welcome to the club!

I am not the biggest expert when it comes to technical stuff however what you are describing sounds like it could be related to the MAP sensor. These can cause all sorts of trouble when they are not working properly, for example my car would start first time and immediately stop because the fuel air mix wouldn't sort itself out. I am sure the more experienced 480 club members will be able to diagnose this however.

If the car is modified then that could potentially cause issues ECU wise, they can be temperamental even at the best of times

Hope this can be sorted, you've come to the right place
Ben

Hi thanks for that.

I wasn't sure they had a MAP sensor. All I can seem to find is MAPs for the Turbo version?

Apologies if I'm being daft.

TheRicer wrote: ↑

Sun Jan 17, 2021 5:32 pm

Hi thanks for that.

I wasn't sure they had a MAP sensor. All I can seem to find is MAPs for the Turbo version?

Apologies if I'm being daft.

Hi Ben and welcome!

First things first there are no daft questions - everyone has to start somewhere with these cars and the fact you're here and keeping another one going is the important thing! Personally I shall only consider anything you ask daft if we've answered it for you but you keep asking it!!

It could well be a temperature sensor and yes there are 3 - air and coolant for the ECU and another coolant one for the Info Centre.

Could equally be the MAP sensor (which is the small black box in the scuttle in front if the triangular relay box marked, of all things, "GM"!

Could equally be a lot of things!

As yours is a 1992 it has the code reader - ancient technology, undeniably clunky yet remarkably clever for its day and more useful than many realise. Start with error codes (if any) from there - it may save a lot of trial and error.

There is stuff on the main site but if you can't find it or it just leaves you bewildered come back to me. If if helps I'd be happy to arrange for us to speak and I'll talk you through it...

Whereabouts are you, by the way?

David

Hello and welcome.

If it is a N/A 1.7 it has a MAP (not a MAF like the Turbo). If the MAP is dead it won’t run for more than about half a second so I doubt it is this in your case.

You are right about there being a few temperature sensors. The only one that controls running of the engine is the one hidden near No. 1 spark plug (to the right of the engine as you look at it— passenger side in the UK; driver’s side everywhere else. Changing it is easy and only a little dribble of coolant comes out when you swap it so no bleeding or buckets required. Not a bad idea to change this but it can be checked with an Ohm-meter at different temperatures— these are in the Haynes manual I presume but also searchable on this forum.

Is the throttle position sensor set up so that it clicks when the throttle cable is given the tiniest bit of tension? This switch tells the idle air control valve to modulate the air for idling. If you haven’t got it set up right the throttle butterfly will be closed before the valve tried to take over.

If you can get codes out of it then this is a very good starting point!

dcwalker wrote: ↑

Sun Jan 17, 2021 5:55 pm

First things first there are no daft questions

The only daft questions are the ones you never ask.

How long was the car sitting waiting? Did you remove the dizzy cap to get better access to the thermostat housing?

Cheers fellas for the help.

I'll start with the code reader as you said. I found an article on the reader early so I'll try find that again.

I would have thought if there was issue with the throttle position sensor then it wouldn't rev up well at all? Where as it's fine when cold on first start up. Then just a cunt when warm.

May I add that the car has overheated before hence the new thermo and housing after doing the radiator, would that perhaps bugger the temp sensor?

I didn't remove anything when changing the thermostat Mr jifflemon and she was sat for a couple weeks, no longer than 3 if I remember but time has become just an abstract thing during Covid.

Thanks again.

Ben

TheRicer wrote: ↑

Mon Jan 18, 2021 5:57 pm

I would have thought if there was issue with the throttle position sensor then it wouldn't rev up well at all? Where as it's fine when cold on first start up. Then just a cunt when warm.

The throttle position sensor isn't a potentiometer controlling "revving up" it is really simple and just tells the ECU when the throttle is closed and therefore to take over idling with the idle control valve. (I think later cars with the 2.0 engine have a WOT (wide open throttle) position but don't worry about that).

I'd be looking at the setting up of the throttle position switch and the engine temperature sensor first personally.

Ahh ken.

Cheers mate. I'll check back in when I get a chance to look. Currently working during all daylight hours.

Hello again!

So I've had a blast at the code reader in port number 2 and I'm getting (in this order):

132 - Battery Voltage (The voltage read 12.8 doing nowt and 14 odd when running)

212 - Oxygen Sensor

412 So Apparently this doesnt exist. I've checked all codes through about 6+ times now and I'm pretty sure I'm seeing it right.

122 - Air Temp

I ordered an air sensor and the coolant one the other day too as they're not expensive. I read the codes, changed the two sensors. Reset the codes.

Started the car and the same thing happened.

Started fine, ran fine, got to around 90 degrees and started to stutter then cut out at 92 degrees.

Do yous have any thoughts on the battery fault code and that 412 reading?

Any experience of oxy sensor symptoms? I'll order one as it's showing a a fault so.

Thank again for any help it is greatly appreciated. I was once a technician of sorts but I am terrible.

Ben

I'd suggest ringing out the wiring between the air temp sensor plug and the engine ECU. As I'm sure you know the sensor just gives a resistance that varies with temperature. If you have a high resistance in the wire somewhere then it will be giving the wrong data to the ECU. The codes you have read come from the ECU and it is telling you that you don't have a reasonable or complete circuit to that sensor.
a
The same with the supply voltage to the ECU: the ECU is not happy with what it is receiving. Check the grounds and also measure the voltage to the ECU.

You will need the pin out of the ECU for the above two tasks. I think Haynes have this.

I'm not particularly au fait with lambda sensors so hopefully someone else can come in to help you with this one. I would have thought though that if the lambda sensor was at fault enough to give a code then the car would run in closed-loop mode (like earlier 480s without the lambda sensor) and still run okay and not cut out after getting hot.

Does it run exactly the same with the air temperature sensor unplugged? It should be able to compensate for this and just run with a default "safe" value.

Cheers fella.

I'll find the time to give thise wires a check.

I dont quite follow this 'You will need the pin out of the ECU'

I'll try with the sonsor unplugged too.

And yeah Iwoul;dn't have thought anything to do with lambda wouold cause a cut out.

Thanks again : D

TheRicer wrote: ↑

Thu Jan 21, 2021 3:36 pm

I dont quite follow this 'You will need the pin out of the ECU'

As in you’ll need to know which pin or wire is the other end of the air temperature sensor at the engine ECU end

jamescarruthers wrote: ↑

Thu Jan 21, 2021 5:23 pm

TheRicer wrote: ↑

Thu Jan 21, 2021 3:36 pm

I dont quite follow this 'You will need the pin out of the ECU'

As in you’ll need to know which pin or wire is the other end of the air temperature sensor at the engine ECU end

I'd start with pulling off the sensor, not sure , but you might do damage if 'buzzing out circuits'
Lamda sensor will just screw up the mixture, not 'kill' the engine?

odd that same temperture each time, measure the resistance of ECU coolant sensor (at dizzy end, front NOT rear as rear is for the info centre?) when cold then repeat when hot / cuts out? HBOL have values, which I'll look up?

Cheers fellas!

If you could get values Alan that'd be lush. I should have got a haynes manual when I bought it to be fair!

I was actaully wanting to sell her as I currently have 3 Volvos and little space. I do love her though.

TheRicer wrote: ↑

Fri Jan 22, 2021 9:12 am

Cheers fellas!

If you could get values Alan that'd be lush. I should have got a haynes manual when I bought it to be fair!

I was actaully wanting to sell her as I currently have 3 Volvos and little space. I do love her though.

I thought it gave BOTH cold & hot readings
coolant sensor
B18E (Fenix) 290 + / - 20 at 20 C

ALL others
2500 + / - 300 ohms at 20 C

Also found this on a piece of copied paper also from HBOL ( I assume for Renault)
2500 + / - 300 ohms at 20 C
280 - 370 ohms at 80C

Air temp black sensor
290 ohm at 20C
320 ohm at 40C, not sure if this is feasible in the UK?

air temp blue sensor
2500 ohm

God I hate electrics.

Thanks for the help Alan.

Yo,

Just thought I'd give an update on the 480. I'd left her for a while whilst the weather was shite and I've been working.

She's running now!

I finally got round to changing the throttle body to a correct 1.7 litre version. I did have a 2.0L type on before hand (this was on for a while and she ran fine in the past).

I was going to just try the throttle position sensor that came with the 1.7 body but just went ahead and changed the whole thing. The only other thing I've done was seal up a small split I noticed in the air filter to throttle body rubber, no idea what that's called.

So she got above the 92 degrees she was cutting out at previously. I took her for a drive without any stuttering.

Only thing was that the idle was high at about 1400 with some hunting for quite some time then finally settled down to 950.

I'll be checking again to see if the same thing happens. (The idle adjust is currently screwed all the way down)

Thank again for all the help.

Glad this could be sorted out, odd how it can just be a small thing causing such issue!

Idle adjust screw???