Quote:
Originally Posted by pch2021
Best compression test: Start with no glow plugs.
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yup, starting (or attempting to start) a diesel with out using the glow plugs (or even disconnecting them to ensure they are not afterglowing from a cut wire...) will sure show a motor with perfect compression right away.
but a motor with good compression 350 or so on all pots when it's been 30 at night, and attempting to start it will fail 99% of the time. what did that show?
IDI motors need glow plugs to start.
starting an older motor without using the plugs is not wise.
starting a cold, STONE cold not run in 12 hours cold, with a single 10-15second glow will show safely how good the motor starts. it'll show weak pots, (by exibiting stumble, and smoke)
how often do scammers have the car totally warmed up before you get there, so it will start smoothly... even if you specifically insist on a cold startup.
I got an SD that was stone cold, started up great with no glow cycle, but the motor smokes like crazy. I'm sure it has bad valve seals, or crap injectors, it might even have an out of time IP or a badly worn timing chain.
all of these things I can evaluate.