Volvo Repair: 88, 740gle poor idle and stalling, plastic screw, screw out

Question
Hello Regis,

I have an 88, 740gle 2.3 maual fuel injection.
When i start it, the idle is eratic at about 5/600 rpm.
It then goes up to 900 rpm while in park, when i put it in to drive the rev's drop to 5/600 rpm, and sometimes stalls.
When i go to pull away it sounds as if it's not fireing on all 4 cylinders and stalls, after i have restarted it and reved it it clears a bit.

But as soon as i get to the end of the street and go to pull away it does it again.

Sometimes it will also do it just after i have pulled away.

This problem of the stalling goes away after i have done a few miles and got the engine warmed up, but the tick over won't go above 5/600.

I have tried adjusting the tick over by turning the large black plastic screw out, infact i turned it all the way out and the rev's never changed.

I have also noticed it does it more on cold damp days, (england is a tad wetter than normal at the moment).

Any idea how i can solve this problem, without resorting to expensive garage fee's.

Rob

Answer
there are many things that can make it run poor without being able to see it all I can do is guess,and there are many things to guess at.I would start with having the throttle body cleaned, and then replace the spark plugs and wires if you feel it is a misfire.