RWD - Permit me an explanation

Volvo RWD 200 Forum

INDEX FOR 4/2014(CURRENT) INDEX FOR 12/2011 200 INDEX INDEX (NO RELOAD) [<<]  [>>]


Permit me an explanation 200

If the manifold to cylinder head gasket dislodges, then air is drawn into that runner alone, not the others. That leans the mixture and may cause a misfire at idle. However, the additional oxygen is seen by the O2 sensor, and that produces a response by the sensor as a lean condition, and the sensor input then causes the ECU to trim the mixture richer. The ECU can only do that for all cylinders, so the other three end up being excessively rich and the engine will then run very roughly. Mixture is adjusted by dwell time - the number of milliseconds the injector is opened, and to an extent by manifold absolute pressure affecting the fuel pressure regulator.
So the problem should be quickly traced - no fuel from that injector, false air, lack of spark, or lack of compression.
The OP should have enough to go on now.


[about brickboard ads]


New No fuel in #3, but #'s 1, 2, & 4 [200]
posted by  LoveMy240Wagon  on Tue Dec 6 18:11 CST 2011 >

[about brickboard ads]

Cut and paste link:

<< < > >>

Users marked in green are currently online.

©Jarrod Stenberg 1997-2012. All material except where indicated. is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.

All participants agree to these terms.
Powered by Denizen - Custom Software for Enthusiasts