OK guys, I bravely tried a cold test tonight. I think on the first try I didn't have the stop linkage pushed far enough, because I smelled diesel after cranking (but it didn't start of course). After that I removed the idle cable so I could push the stop linkage farther, all the way. I used a socket bit between the pump and arm and it held fine. But I'm wondering if getting fuel in the cylinders in the first place messed up the test, even though I let it sit for a while after that try (and each try actually). My numbers don't sound right: Numbers 1, 2 and 4 were all around the 340 mark and number 3 registed 400.
Does fuel injected during the test cause false highs? I don't mean to be a skeptic, but I don't feel like my 366,000-mile engine would have a COLD (has not run for three days) compression of 400 psi (I'm understanding cold compression test should yield lower numbers, right?). It does start pretty easily, but ...
Other observations: The first two glow plugs had light oil on them when i removed them, and a small bit of oil dribbled out of four glow plug holes during the test ... with a light fuel smell.
During the #3 test, it looked like light smoke or steam was coming out of #2, but I did not notice it again while testing #4. I did notice light oil "spray" on the side of the IP from the open holes.
I want to do a proper full temp compression test tomorrow, but don't want to proceed until I know I've got the fuel shut off correctly. I did try pumping the MityVac on the shutoff while I cranked, on the final cylinder, but not sure if it made any difference. Thoughts? Is a little diesel smell normal during the test?
I guess once I get the glow plugs back in and the car warmed up, I can try starting it again with the same stop linkage setup ... if it doesn't start, would it be OK to assume the fuel is adequately restricted?
An alternative would be to try this with the injector holes instead of glow plugs, I suppose.
