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Volvo 940, B230FK -1995 rough idle...

Normally, I think I can fix almost everything on a car, but this one... Ok , please read and be surprised (ehrm... ok, I know...)...

I've tried everything... Ignition: Spark plugs - new Cables - new Distributor cap - new Distributor parts, all new..

Fuel: Injectors cleaned Wireing checked... Fuel pump, ok Fuel press., ok Lambda, ok

Air: New filter Hoses, ok AMM, ok Intercooler, ok Turbo, ok

Else: Normal temp. Oil consumption, ok - close to nothing. No bad noises... Enough power while coasting and accelleration... Fuel consumption, ok (according to user manual)

Once in a while the engine seems to stall, but catches up and runs ok again... No system in the "caughs". Very random. Warm engine and idle at factory settings. It's like a human flu... random caughs... A very mild smell of burned oil... Strange... Example: Red light at a crossing, and stopping, engine at idle, rough idle and a mild smell of burned oil...

Help!... Anyone...

Reply to
Knut Solem
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Hmmm. I have the same problem. Here's another vote to find the solution.

Once before though it was faulty plug cables... but you say you've replaced those.

TKM

Reply to
TKM

With the limited information you have provided I'd suggest that your symptoms are consistent with a lean stumble. Over a period of time intake valves will develop carbon deposits on the surface constantly exposed to incoming fuel. At some point the deposits become heavy enough to absorb fuel as it is injected leading to a shortage of fuel in the cylinder. This is especially true at closed loop/hot idle and is much less obvious under throttle.

We use a Snap-On/Motorvac fuel system cleaner to address this condition. Your mechanic can provide more information.

Regards

Reply to
pathayes81946

skrev i melding news: snipped-for-privacy@o5g2000hsb.googlegroups.com...

Thanks for trying to help. I'm sure someone in this community knows the problem and the solution.

Well known problem the carbon deposits. But a few weeks ago I had to mount a new cylinder head gasket because of a crack in the gasket causing a coolant leak. An inspection of the cylinder head revealed nothing strange. No deposits on the valves or in the combustion chamber. Cylinder no 4 had traces of oil on the pistion top. Not much, but using a paper towel I got small traces of oil. The other cylinders was all fine. The oil consumption is normal. Close to nothing.

The car runs well, and has enough power. The problem started more than a year ago, so I'm starting getting a bit xxxxx (fill in with suitable word...) now.

Ask the Volvo shop... no chance... They won't answer unless they get paid for it... Once I tried, but the answer was: spark plugs, cables, water in the fuel, and so on... Nothing revolusionary new...

Reply to
Knut Solem

I had this exact problem and now is cured. There seems to be an issue with the engine management system. Here in the UK, an item on the BBC consumer advice program called "Watchdog" revealed that quite a few Volvo owners were having problems like this. Volvo agreed to modify the EMU free of charge to owners of certain types of Volvo. Mine was one of these so I had it done and now it's great. No idle problems. Here is the TV program website link

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this helps. Steve

Reply to
Steve L

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