Volvo b230a

[Partner]

Hi, so i have a 240 b230a -85 and ive been wondering why it runs a bit rough. And to be honest it have done tgis for few years but always works so not been in a rush ro fix it. Sometimes after turning the engine off the car starts "dieseling" and after that if the engine is warm its hard to start it again. But if i wait for the engine to cool down no problems. And the second thing im wondering about intake manifold has an adjustment screw of a sort right next to the carburetor and im not sure what it does. When i turn it open the engine rpm goes higher a bit.

[Othen]

Hi,
Have you checked all the normal maintenance stuff (filters, plugs, ignition timing etc) and for leaks in the hoses? If you have done all that then it sounds like a carburettor tuning issue. Here is a link to the green book for carburettors from from 75-84 (I'll make the link available for about a week so you may download a copy for yourself):

https://1drv.ms/b/s!Ask6E_1jz4xIgYRg...Dnwzg?e=xdAu9f

There should be enough information there to solve the rough running and dieseling problems (if they are due to the fuel/air mixture and not something mechanical).

I'm guessing the screw you describe in the adjuster for the anti-dieseling circuit, which you may see here:



... and is part #7 on this picture:



... here is how you check out the anti-dieseling system:



It sounds like either the anti-dieseling solenoid isn't working, or the slow running adjustment is turned up too far at the same time as the anti dieseling adjuster is restricted too much.

Good fortune,

Alan

PS. I don't have a green book for 1985 MY, if it is not covered by the 1984 book just google it and you should be able to find a copy for yourself somewhere on the Inter-web.