Hi.
My 1990 T2 only runs on the front rotor, the rear rotor appear to have no compression at all.
So, I took a video from the rear leading spark plug hole, and it appears that is completely missing an apex seal.
The video starts with a view from a good apex seal, then as the engine is rotated you see the second apex seal grove appear and then on the third one it appears there is still some seal inside the groove or maybe is just the spring, can't see very well. Video was taken with a phone filming the endoscope screen, so not perfect.
Here is the video:
https://drive.google.com/open?id=0BzULttyruY_ScnJmRW9kcUc0N28 (https://drive.google.com/open?id=0BzULttyruY_ScnJmRW9kcUc0N28)
What i want to ask is, the engine is stock with 56K miles, so with OEM apex seals what are the chances that the housing and turbo are going to be OK?
I have no ideia how this happened, I bought the car that had been sitting for about 15 years, I knew it wasn't running on both rotors but thought that maybe it was just dirty and stuck primary injectors from all the years sitting. And the funny thing is after about 4Krpm the car sounds that is running fine (hence my thought about primary injectors dirty and secondaries kicking in).
So, money is a bit tight now but that will give me a chance to open up the engine and think about what parts need replacing and other goodies that come with rebuilds (porting).
Best Regards
Unfortunately once the engine revs get up the engine will sound ok even on one rotor.
A cheap piston compression tester like the one one this link will tell you what is going on.
Simply leave one plug in each Rotor housing wiz it over and check the readings one to the other.
http://www.ebay.co.uk/itm/Automotive-Petrol-Tester-Kit-Timing-Cylinder-Engine-Gauge-Pro-Compression-Valve/301842142738?_trksid=p2045573.c100506.m3226&_trkparms=aid%3D555014%26algo%3DPL.DEFAULT%26ao%3D1%26asc%3D20151005190705%26meid%3D0fc26837c5af45bb96ac8101fa42f28b%26pid%3D100506%26rk%3D1%26rkt%3D1%26
Well it's pretty obvious that no compression will be the result, there's two apex seals complete missing from the rotor slots.
But I did actually ran a test and on the front I had about 100 psi even on all the needle jumps.