Volvo 480 Club Europe

From very cold my 480 idles very slow....I need to reset it, but I still can't find the other side of the two wires which I need to connect to set it. Everything else has been checked...engine temp sensor, idle valve, fuel ecu, throttle position sensor etc....so its just this standing in the way of a smooth idle when she is cold in the morning. I even went to Volvo today to see if anyone could help...I thought it would be a waste of time before I got there, and yes, I was right, it was a complete waste of time. Could someone please help me and tell me where this illusive wire might be hiding??

I have been told I need to earth it....but probably not my problem, which leads me to the question....what can it be!!?

Its that its broken

A longshot Rach but try the 2 rigid pipes which go into the inlet manifold.If theyre not pushed in fully you'll get an airvs leakvm.

Thanks for that, will have a look.

Thanks for that, will have a look.

Parts changed or tested

IDLE VALVE
THROTTLE POSTION SENSOR
ENGINE ECU TEMP SENSOR
TEMP SENSOR
CRANK SENSOR
MANIFOLD
VAC LEAKS
FUEL ECU
IGITION ECU
PIN 11/12 ON ECU
SPARK PLUGS
DIZZY CAP
ROTOR ARM
HT LEADS
MAF
INTERCOOLER PIPES
OIL CHANGED
RECIRC VALVE

THINGS TO TRY

OIL SEP VALVE & VAC DIAPHRAGM
OXYGEN SENSOR (I DOUBT)

I have spent much time on this problem but so far I don't have the answer.

I have the exact same problem - idles too low when cold (juddering like mad) but fine and stable when warm. Has never done it before, only did it after cylinder head was replaced, so I was thinking it was a sensor somewhere. They are all fine though, I think, unless the idle valve is getting a back-to-front signal (high idle when warm and low when cold? If that can happen?)

I don't know if you can test the transistor in the fuel ECU by checking voltages across the idle valve wires? Not sure what to look for, but the values I get with the engine running are a bit weird, and do fluctuate. What's more, on disconnecting the idle valve there is no change at all in idle speed, whereas before there was, I think.

On my last trip to Bristol I also only got 27mpg!!!!!! As opposed to my usual ~44mpg. Yet car runs amazingly, so can't be too rich.

That's Vader head right? I never had any idle issues. I removed my new sensors from that head before selling so I doubt it's sensor or head related on both cars.

I still vote oil sep valve but of course I don't have a spare and removing from mine to test is a bad idea as they break whenever removed trust me at £40+ there not cheap.

course vader never had the valve

Well I know for a fact that the oil sep valve is knackered, so that's coming off then!! Just plug up the neccessary pipes and whack a filter on the breather, yes? Didn't think it would make that much difference. The diaphragm in my recirc valve's also split, so I'll have to replace that too. Maybe that's all that's wrong with it...Thanks for the help.

The oil valve can screw it up.

The diaphragm just off the idle valve could be the problem with rachel's 480.

Want to borrow one?

Right, I have now checked/replaced everything I could and the idle when warm is still too high. The idle valve seems to move well enough, and with the pipes off whilst starting the engine, it moves so I'm assuming the ECU is working as it's sending it a signal. I noticed that when I allowed more air through the pipe, the rpm dropped. So I'm thinking that if it is the diaphram just off the valve that's gone (as you've suggested Martin) then it's not opening enough at idle to let enough air through.

It is the only thing possible left (again as you said Martin) so I might have to try it. I have looked for the part tho, but can't find it? Richard suggested using another recirc valve, but I'd need larger pipes for that. Does that diaphram thing come apart to be checked? If Rachel has tried Martin's spare idle valve diaphram (no idea what it's called) has it worked?

Thanks

Hi Crispy-d. I have only just got the part today, so I'm hoping to know tomorrow. All my fingers are crossed. It wasn't cheap either....40 odd quid!

Haha - yes I just got back from town. Haven't come back with one for that reason! £47, and it has to come from Sweden apparently, so that's then 2 days for delivery (which looking at it isn't that bad). I don't want to order that until I know it'll make a difference. Another 710N recirc valve plus some pipe adaptors would be cheaper

Best of luck with it!!

Cheers mate, will let you know asap

I got mine for £42.54, ordered it on tuesday.

Yipeeee!! It's worked!! Out there first thing this morning to change it over and low and behold on turning the key she sprung into life none of those low revs! So pleased.....Go for it Crispy-d and have yourself higher cold start revs

In my joy I forgot to thank Martin for his work trying to sort out Serendipity and for his final diagnosis
Also a general shout out to all and for the forum for being such a great one!

Ah good stuff, nice one Rachel! I'm off to get one then!
And yes, thanks to Martin also who pointed it out, otherwise I'd probably never have noticed it being there.
Glad yours is working, anyway.

Regards,

Crispin

Splendid news! I'm happy to be of help.

Mart

Nice one Raquellus!

Nowt like having summit finally done thats been fucked for ages!