the koh I'm using has been left with lid off container and a bit old will this affect reaction
Yes, the KOH will have carbonated and you'll need to use far more than normal.
This will be a big contra bution to your problems.
You need to get some new KOH before you try another batch.
Now this next bit is something I've never posted before, on any of the forums I use.
If you do not replace your KOH and keep asking why you can't get a 27/3 pass I for one will not be offering any further advice.
Making bio can be dangerous unless some simple basic steps are not followed,
1, methanol fumes can kill, all aspects of the process MUST done in a manner that releases as little methanol fumes as possable,
not by opening the lid of a reactor containing hot methanol rich bio to scoop out a capfull , the only thing that could make this worse would be lighting a cigarette at the same time.
2. KOH, NaOH are highly corrosive and WILL burn you if it comes in contact with skin, it may blind you if it gets into your eyes.
Both of these chemicals need to be handled with great care.
3. All advice given is drawn form a collection of many many years experience of making bio, we (the forum members) will not tell you to do something dangerous, we are only trying to help you make good bio SAFELY,
by not heeding our advice you may just damage your van, but you may also kill yourself and others around you.