Last year before I had to put my 300D in storage, I replaced my oil cooler lines. In the process, I dislodged pretty much all the smaller vacuum lines near the brake booster. Thanks to diagrams I found on this forum, I got everything important connected again. The thing is, the car still takes eight seconds to shut off after I turn the key switch off. Back when I first bought the car, it took about a second to shut down. I went to Harbor Freight and bought a handy-dandy handheld vacuum pump with gauge. Doing some testing with this, I found that the shutoff actuator at the back of the IP will shut the engine off from idle with 5" Hg of vacuum. However, it takes about five squeezes of the hand pump to supply this much. That seems like a lot to me.

What I'm wondering is whether the actuator is needing more air evacuated than it should in order to function, or whether the vacuum being supplied, in terms of quantity of air evacuated over time is less than it should be. When I hook up my gauge to the nipple on the main vacuum line, I end up with 18" of vacuum, but it takes about 9 seconds to get there. The power brakes work fine as always.

I removed some old hoses and Y-fittings and replaced them with fresh hoses and tees. This got me from not shutting off at all to the current eight second time frame. I have a known vacuum leak somewhere in the lock system (will get to that later), but I have the locks plumbed to the other nipple on the big line and it didn't make any difference in the shutdown time whether I had this hooked up or blocked off.

Ideas? Info?


Edit: 1588 posts. Spanish Armada!

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.