Need to replace the struts simple,
Get your hands on some Strongarm struts PN6207 ( or from a 94 to 98 Ford EF, EL wagon). They are an inch shorter and stronger gas pressure than the 86 ones.
Find a late model Commondore and remove the strut mounting balls from the bonnet ( you will need to find 4 of them for each end of the two new struts), they are slightly longer than the ones in the 86 gas strut but is the same thread diameter.
Put it all together and you have a hatch that stays up..
Sprinter Veteran
Or just use ae82 struts which go straight on and are slightly longer so that the boot opens a little more for tall people![]()