1998 Volvo S70 Engine Stalls

Tiny
MEFUCHS
  • MEMBER
  • 1998 VOLVO S70
  • 6 CYL
  • FWD
  • MANUAL
  • 125,000 MILES
I have a 1998 Volvo S70 Turbo that trys to stall while idling. If I push in on the clutch the rpms jump back up to normal 1k or so and its fine. I have notice a smell also coming from the exhaust (strong sulfur smell which is not normal). When the idle drops low the check engine light will evently come on. I checked the DIL with a code reader and it s reading a PO171 lean fuel mixture Bank 1. When I clear the code the problem goes away for around 500 miles but will evently come back as before with the low idle and a stall when sitting still. It will start up after it stalls but I can see the tach needle drop as before. Pushing in on the cltch while sitting still make the proble go away. I'd hate to keep having to push the clutch in while still. Cluch job is in the couple thousand price range.

Any ideas. Thanks
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Tuesday, August 19th, 2008 AT 9:54 AM

3 Replies

Tiny
RASMATAZ
  • MEMBER
P0171

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)
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Tuesday, August 19th, 2008 AT 4:42 PM
Tiny
MEFUCHS
  • MEMBER
I agree> The P0171 is very general and could lead to alot of unnecessary repairs. Although can you explain why pushing in on the clutch when the engines about to stall (sitting still) brings the engine back up to a smooth constant idle, but if I release the clutch and idle it will try to die. To me sounds like a vacum issue. Does the clutch engage something that reduces the vacum pressure on the volvo?
Thanks
-M
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Thursday, August 21st, 2008 AT 2:23 PM
Tiny
RASMATAZ
  • MEMBER
When you depress the clutch it uncouples the transmission from the engine there's no load to it. Dunno about Volvos having a vacuum switching valve that the computer uses to control idle speed. It could be vacuum leak I would check that before the others I've mentioned go from there
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Thursday, August 21st, 2008 AT 3:05 PM

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