'wobbling' idling speed-volvo940

Hi! I have a Volvo 940 Kreg automatic saloon with a B200F 2.0 litre petrol engine ,no air conditioning, and would be grateful for help in sorting the following problem. When the car idles,the engine does not run at a constant speed but fluctuates in the 700RPM range and can at times be felt as a shudder through the seat. I have replaced the coil, distributor,spark plugs and leads.The only thing I can think of is the fuel injectors,which I have no experience of fixing. When starting the car from cold in the morning, sometimes the accelerator has to be pressed or the engine stalls.This is also the case when starting it when hot ,minutes after the engine has been switched off. If the car has been used that day but the engine has been switched off for 15 minutes or more ,itstarts O.K. There are no faults recorded on the diagnostic system. I would be grateful for any advice on what the problem could be and if it is injectors-how to clean /diagnose them. Thanks Alex

Might be your throttle body ? Check here to see if this looks similar to your symptoms Scroll down the link a little & look for "Idle Problems: Poor Idle, Idle Surge and Hunt: Cleaning Your Throttle Body. .Throttle Body: Before and After Symptoms and Why You Should Regularly Clean Your Throttle Body."

Hi, I would, as above, check/clean the throttle body. But I would also clean/check the idle control valves for both hot and cold. You may also want to check/clean the crankcase vent systems pipes and flame trap. Des. . . ;)