When I bought my '82 240D the car looked pristine but it only idled on three cylinders ~ using the fast idle cable made it O.K., when I adjusted the valves the #1 exhaust valve would only get about .010" clearance and it still had a very strong soft miss @ idle, eventually I replaced the #1 cylinder's injector and it idled and ran fine for several more years, every 5,000 miles or so the #1 cylinder's exhaust valve would close up to zero lash and I'd open it as far as it'd go, never reaching anywhere near .014", in due time it got to .002" lash cold and the idle miss became bad, causing a large rhythmic 'THUMP' like a giant pounding the bottom of the car, this stopped the *instant* it went off idle and eventually even a proper set of four matched rebuilt injectors made no difference and the lash, cold or hot was at zero, I took the engine apart and along with myriad other worn out things, the #1 cylinder's exhaust valve was tulipped .

So, no harm in #1 adjusting those damn valves, why no one ever does it until the car's close to dead I'll never understand .

Then take all four injectors to a competent Diesel service shop and stand there and watch whilst they pop test all four (it takes less than 5 minutes no any excuse means they're dishonest) and unless all four are perfect, replace them .

This might well get you a few more years and tens of thousands of service .

Low compression is bad yes but, it will run passably well with anything over 250# compression if you're just looking for cheap transportation .

BT, DT, drove it across America , the Continental Divide (serious hills, that) and so on sans any troubles apart from going slowly all the way there and back so don't let the check book crowd make you give up just yet .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better