850 2.5 20v high idle

TurnipSpeed · Dec 1st, 2012, 23:18

Hi,I have just bought an 850 2.5 20v estate after sending my 940 to the knackers yard(5 years reliable service).
It idles at 1100 rpm and the ignition system(lambda?) light is on.
The previous owner said it had the codes read and only needs new ht leads.
I'm not so sure, but I don't know where the plug for the diagnostics is on the car or what diagnostic system the car uses.
Any advice would be appreciated.The car is in excellent condition but has done 193,000 miles.
Thanks, Paul.

Thanatos · Dec 1st, 2012, 23:48

Depending on year look under the coin tray under the ashtray or it could be under the bonnet

Chris_Rogers · Dec 2nd, 2012, 08:50

You also need to determine which engine management system the car has.
Could be Jetronic (uses flash codes) or Motronic 4.4 which uses a scan tool (either Volvo or OBDII).

Open the black plastic ecu housing box behind the righthand headlight.

Count the ECU's:

Manual box; 2 ecu's = Jetronic, 1 ecu = Motronic.

Auto box; add one to the above.

S70 B5254T · Dec 2nd, 2012, 10:27

I'm not qualified, but my car had similar symptoms when I bought it, and it turned out to be this, so this is one possible solution for you...

Check your idle air control valve - take it out and tilt it from side to side, and if it doesn't "click", then try cleaning it with carb cleaner; if that doesn't free it up, then you should pick up a pre-owned one on here for <£20.

scutyde · Dec 3rd, 2012, 08:35

Also inspect the small vacuum hoses which run to the throtle body...
Which MY (Modell not Manufacture)

S70 B5254T · Dec 3rd, 2012, 11:11

Your location says County Durham, so I'd suggest a trip to Bishop Auckland to see Chris (forum name RiPsTa33); he offers free code reading and he stocks and fits most parts that you are likely to need - highly recommended from personal experience.
Nick

TurnipSpeed · Dec 3rd, 2012, 12:16

Thanks for the advice.I have been to see RiPsTa33 with a v70 diesel(kept 2 months but hated the auto box) and my 940 just before I got rid.
He was very helpful, but didn't have many 940 bits, which was another reason for getting the 850( very useful to have a local enthusiast).
I just think that for my money( not much!) these older Volvos offer an unbeatable ownership experience.
Thanks again , Paul.

KBB · Dec 3rd, 2012, 12:27

Have you got the EML on? The ISVC circuit on these usualy have a good self diagnostic capability. A high ide could also be an air leak! If you nip the hose on the air filter side of the throttle body and the RPM drops then the ISVC has gone open circuit and is in its fail safe mode.

If the is no change in the RPM then I would be looking for an air leak.

TurnipSpeed · Dec 3rd, 2012, 19:09

Hi,KBB, excuse my ignorance but what is the ISVC circuit?
Waiting for a Haynes manual to arrive so I can get familiar with the car!
Thanks, Paul.

KBB · Dec 3rd, 2012, 19:33

Quote:

Originally Posted by TurnipSpeed

Hi,KBB, excuse my ignorance but what is the ISVC circuit?
Waiting for a Haynes manual to arrive so I can get familiar with the car!
Thanks, Paul.

ISCV (Idle speed control valve)

The should be 2 hoses coming off it, one is on the air filter side of the throttle plate the other on the engine side. If you nip closed one of the hoses and the idle speed drops then the ISCV is the fault. If the is no change in RPM then it's an air leak.

Dec 1st, 2012, 23:18	#1
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	850 2.5 20v high idle Hi,I have just bought an 850 2.5 20v estate after sending my 940 to the knackers yard(5 years reliable service). It idles at 1100 rpm and the ignition system(lambda?) light is on. The previous owner said it had the codes read and only needs new ht leads. I'm not so sure, but I don't know where the plug for the diagnostics is on the car or what diagnostic system the car uses. Any advice would be appreciated.The car is in excellent condition but has done 193,000 miles. Thanks, Paul.

Dec 1st, 2012, 23:48	#2
Thanatos VOC Member Last Online: Sep 11th, 2019 14:36 Join Date: Aug 2008 Location: Blackpool	Depending on year look under the coin tray under the ashtray or it could be under the bonnet __________________ Classicswede quote " I knew I had not done the bolts up." http://www.volvoforums.org.uk/showthread.php?t=159255

Dec 2nd, 2012, 10:27	#4
S70 B5254T ☭Nick☭ Last Online: Jun 22nd, 2014 23:30 Join Date: Oct 2012 Location: Lincolnshire	I'm not qualified, but my car had similar symptoms when I bought it, and it turned out to be this, so this is one possible solution for you... Check your idle air control valve - take it out and tilt it from side to side, and if it doesn't "click", then try cleaning it with carb cleaner; if that doesn't free it up, then you should pick up a pre-owned one on here for <£20. __________________ 1998 Volvo S70 CD 2.5T 20 valve (B5254T) Community First Responder transport & Daily Driver previously...1994 Volvo 854 SE 2.0 20 valve "L411XCC" & 1999 Volvo S40 2.0T SE "T283LTW"

Dec 3rd, 2012, 08:35	#5
scutyde Retrofit master Last Online: Mar 28th, 2022 10:14 Join Date: Mar 2010 Location: Berlin	Also inspect the small vacuum hoses which run to the throtle body... Which MY (Modell not Manufacture) __________________ Volvo 850 2.5 20V MY95 Pictures Here what I retroffited so far List

Dec 3rd, 2012, 11:11	#6
S70 B5254T ☭Nick☭ Last Online: Jun 22nd, 2014 23:30 Join Date: Oct 2012 Location: Lincolnshire	Your location says County Durham, so I'd suggest a trip to Bishop Auckland to see Chris (forum name RiPsTa33); he offers free code reading and he stocks and fits most parts that you are likely to need - highly recommended from personal experience. Nick __________________ 1998 Volvo S70 CD 2.5T 20 valve (B5254T) Community First Responder transport & Daily Driver previously...1994 Volvo 854 SE 2.0 20 valve "L411XCC" & 1999 Volvo S40 2.0T SE "T283LTW"

Dec 2nd, 2012, 08:50	#3
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	You also need to determine which engine management system the car has. Could be Jetronic (uses flash codes) or Motronic 4.4 which uses a scan tool (either Volvo or OBDII). Open the black plastic ecu housing box behind the righthand headlight. Count the ECU's: Manual box; 2 ecu's = Jetronic, 1 ecu = Motronic. Auto box; add one to the above.

Dec 3rd, 2012, 12:16	#7
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	Thanks for the advice.I have been to see RiPsTa33 with a v70 diesel(kept 2 months but hated the auto box) and my 940 just before I got rid. He was very helpful, but didn't have many 940 bits, which was another reason for getting the 850( very useful to have a local enthusiast). I just think that for my money( not much!) these older Volvos offer an unbeatable ownership experience. Thanks again , Paul.

Dec 3rd, 2012, 12:27	#8
KBB Master Tech Last Online: May 18th, 2020 10:57 Join Date: Dec 2006 Location: On Contract Dubai Automotve Technical Academy	Have you got the EML on? The ISVC circuit on these usualy have a good self diagnostic capability. A high ide could also be an air leak! If you nip the hose on the air filter side of the throttle body and the RPM drops then the ISVC has gone open circuit and is in its fail safe mode. If the is no change in the RPM then I would be looking for an air leak.

Dec 3rd, 2012, 19:09	#9
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	Hi,KBB, excuse my ignorance but what is the ISVC circuit? Waiting for a Haynes manual to arrive so I can get familiar with the car! Thanks, Paul.

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