Vacuum leak fixed!!!

[tlister67]

I finally put a vacuum gauge on the intake and found 10 in of vacuum at idle. My idle has been slightly flaky but was not sure it was electronic or leak until then. My understanding is that more like 15 in is ideal. I sprayed starter fluid on all the normal culprits and nothing. Then I sprayed the injector ports and at least 2 were leaking. I went to the local shop and picked up a whole set of injector o-rings. I was not really prepared for the wrestling match of getting the injectors out, O-ringed and back in (2-1/2 hours - keep your day job). In fact two of the injectors had the end caps stuck in the manifold. Luckily they snapped back onto the injector firmly. Put it all back together (almost everything fought going back together). Started up and now I get a pretty good 750 rpm idle and 13 in vacuum. :redspot Perhaps it could be lower but I feel good (and tired).

[Bert Poliakoff]

If any of you guys ever drop the end off an injector, tape a piece of vacuum hose, that will fit in the spark opening, to your vacuum cleaner, and you should be able to get it out.

[JRanmann]

(If it doesn't raise your blood pressure too much ?)

The reading on your vacuum gauge might be bit low (you are correct at 15 inches) but the important thing to remember, both about compression and vacuum is that you are not necessarily looking for a number per se..as what you are really looking for (with either gauge) is variation or lack thereof.

i.e. 13 inches of vacuum that's steady as a rock is ideally better than 15" that fluxuates wildly...as that flux is indicative of one cylinder not pulling it's own weight and much like a 747 airliner, the M30 is capable of 'flying' on five and a half cylinders but the sacrifice is smoothness, fuel economy and the fact now that each the other five have to do 120 percent of the work each would normally be called upon to do, thereby causing premature wear everywhere, due to the increaded 'load' and is something to further investigate and remedy, prior to possibly causing overheating on a hot day next summer when you least expect it... and lunching your engine prematurely.