Macrobb
Full Access Member
Yup, exactly that.
A lot of common problems on other engines are easy fixes on an IDI:
White smoke at idle or full throttle - Unless you are losing massive amounts of coolant, it's probably injector timing. IP is shot - replace IP+injectors. Usually acompanied by missing if at high revs.
Blue smoke at idle or under throttle - really retarded timing(not burning oil). Again, fuel system issues.
Black smoke at anything other than W.O.T - advanced timing won't help(and you'll hear a lot of clatter), or simply the pump is turned up too much(overfueling).
Hard starts when cold - glow plugs. If it fires right up, dies and needs lots of cranking to fire again - air intrusion/fuel draindown.
Hard starts/no starts when hot - pour cool water on back of IP, then try. If it fires right up - Bad IP. Replace IP+injectors.
About the only time you go "Yup, time to rebuild" for a bottom end is if you have massive bearing wear, or if you are using a ton of oil(and it's not leaking out).
I had a block that had .020" of bore wear at the top. It used a quart of oil every 60 miles. It still started right up and ran just fine, though the power was not that great... at least below 1600 RPM, where the turbo isn't spooled. Once the turbo spools, it doesn't matter how worn the engine is...
Oh, and just to add to this - even burning a quart every 60 miles, it did *not* smoke. Because the timing was correct, it just burned the engine oil cleanly.
