I have not been here in a long time. former "volvito". I had to open a new account. Been busy trying new ventures. The old 940 wagon is my lifehood now. I go around fixing houses and the wagon is far more usefull than a truck. The little brick has been so faithfull to me, never complaining until now. I have a little weird problem I can't figure out. Sometimes the rpm is up to 1,200. Then if I turn the engine off and start again is normal. I have no air leaks that I can find. The engine runs normal most of the time until this happens at least once a day during my errands. Thanks

Thanks for all the ideas. Certainly helped me to solve the problem. So far it looks like random bad contact in the coolant temperature sensor. I put some electric grease on the contacts and the problems has not showed up again.

No takers on this one. It has not happened any more. Go figure what the glitch was. Maybe next time. I will let you know if anything happens. Thanks everyone for the ideas.

Thanks everyone for the ideas. I will post back when I find and correct the problem

Thanks everyone for the ideas. I will post back when I find and correct the problem

See the FAQ for tips on throttle position switch, engine coolant temp sensor for FI computer, and intake air vacuum leaks.

Thanks Steve. I may replace the temp sensor. The other two I have checked and seem ok, but since is random problem hard to figure out. The throttle sensor does the click when it suppose to, but I guess that does not mean is completely functioning.

Have you tried cleaning out the idle control valve?
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

yes I cleaned it, but I can clean it again. maybe a bit sticky. thanks

.... and check for OBD fault codes. Your is a 1995 is Bosch engine management. Though I'll imagine without Turbo?

If the throttle position switch (TPS) was failing, either you lose idle function, or the idle control system engages while in flight, as you accelerate, open the throttle body, causing the engine to "bog". Unless the TPS is maladjusted. Though you're right, the TPS can begin to fail and the LH-Jet fuel control / EZK ignition system won't report it a a fault until it the TPS is really bad.

Else, as other suggest here. Hope that helps.
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I am also thinking the problem is the TPS. This car has the old manual code reader. I don't think it tests the TPS, but I may be wrong.

https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

Yes, on a 1995 Volvo 940, you can check for OBD fault codes, and also perform a stepped-procedure diagnostic.

So, check for fault codes.
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Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.