I have a 2.0 MPS and a 1.7 MPS. Before I sell them, how do I test vaccum. Do I need some kind of fancy tools or a hoover?

dr

Get a Mighty Vac hand vac pump. Pull 15"-20" of vac on them. Concensus seems to be if it holds for 5 mins they're good. Another view is that if they leak down less than 2" per minute they are ok.

Next..............,

That tests the ability for them to hold vacuum.

It does not, however, tell you if they work or not.

FWIW, I have an MPS that leaks at the rate of 1" per hour. (25 hours to drop 25 inches of vacuum; it's probably a tester problem, not an MPS leak.) And it's dead as a doornail.

G.

Check at http://members.rennlist.com/pbanders .

There are tests that will tell you definitively that the MPS is dead. I don't know of any simple test that definitively tells you that the MPS is good, except running it on the car. Using the WaveTek meter probably will do it as well, but that's specialized equipment that most of us don't have.

--DD

Ahh Damn, you guys take all the hope out of it.

Suck on it and then put your tounge over the hole. If it holds vacuum, then that part of the MPS is good. (Diaphram) Alot of shops drill holes in the screw plug in the back of the MPS to further adjust the MPS when a teener will not meet the required CO that the factory requires. Also the first teeners did not have a potentiometer on the EGU for that adjustment.

What do I say if someone finds me sucking on a piece of my car?

but seriously, I will try that.

thanks,
dr

I dont mean to challenge Ottos experience, buit sucking on it with your mouth will not tell you much, because you cannot begine to develop the suction level needed that the intake will impose on the MPS. Sucking on it with your mouth will not even indicate a leak...just a total failure. A vacuum gauge is the only reliable tool to determine if the MPS will hold a vacuum.

I'm so glad we're switching to webers.

dr

with Bowlsby as using your mouth doesn't work. You need to pull 15hg and it should hold that for 5 minutes. Yes, if its leaking slowly the MPS will still work but not well. You can also test the field using an ohm meter but its easier to just plug it in a car to test it. I test run all the MPS's I adjust/repair to make sure they run right. Some just run like crap for some reason, must be some electrical problem inside.

Carbs are fine but I still like the throttle response of Djet!

Geoff

And I agree with Geoff.

BTW, the knob on the ECU: It adjusts the CO at idle only.

The drilled-out full load stop is for adjusting part-load.

G.

Just tell 'em that you really LOVE your 914.