Volvo 940DL Station Wagon (1994)

My Volvo has been giving me trouble when starting up after short
periods of standing time. I don't have problems after the car has
been sitting for quite a while (usually at least 1 hour): It starts
up just fine, and I have no trouble shifting into gear. Everything's
fine in the morning on my way to work; at lunch, if I go out; and at
the end of the day on my way home.

When I do have problems, the car will start up, but the revolutions
are at approximately 450-500, and the engine dies unless I pump the
gas. When I take my foot off the gas to go to the brake and put the
car in gear, it also dies. As long as I keep the gas going,
everything's okay. I can usually "nudge" it into gear by keeping my
left foot on the brake and giving it a little gas with my right. Once
I get it into gear, no problem at all: It runs fine, and there are no
other symptoms.

Anyone out there who can give us a clue as to what might be wrong?
Sure would appreciate your help! Thanks in advance!

 

My 940 does this every time the engine has anything done to it. I have to
remove fuse No.1 from its socket (behind the dashboard ashtray), wait a few
minutes and replace it...
That will reset the engine management and probably set the idle correctly.