 testing MPS, how to do it???? |
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| machina |
 Mar 30 2004, 03:20 PM
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#1
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Advanced Member  Group: Benefactors Posts: 2,030 Joined: 21-June 03 From: Miami Beach, FL Member No.: 848   |
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 |
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| SLITS |
Mar 30 2004, 03:24 PM
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#2
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
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.............., |
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| garyh |
Mar 30 2004, 04:18 PM
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#3
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Member Group: Members Posts: 170 Joined: 8-January 03 From: San Mateo, CA Member No.: 114 |
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. |
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| Dave_Darling |
Mar 30 2004, 04:57 PM
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#4
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914 Idiot Group: Members Posts: 14,984 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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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 |
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| SLITS |
Mar 30 2004, 07:11 PM
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#5
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
Ahh Damn, you guys take all the hope out of it. (IMG:style_emoticons/default/headbang.gif)
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| otto |
Mar 30 2004, 07:51 PM
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#6
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Member Group: Members Posts: 158 Joined: 21-August 03 From: Venice, CA. Member No.: 1,056 |
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.
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| machina |
Mar 30 2004, 08:11 PM
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#7
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Advanced Member Group: Benefactors Posts: 2,030 Joined: 21-June 03 From: Miami Beach, FL Member No.: 848 |
QUOTE(otto @ Mar 30 2004, 09:51 PM) 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? (IMG:style_emoticons/default/unsure.gif) but seriously, I will try that. thanks, dr |
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| JeffBowlsby |
Mar 30 2004, 08:22 PM
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#8
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914 Wiring Harnesses Group: Members Posts: 8,499 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None
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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.
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| machina |
Mar 30 2004, 08:27 PM
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#9
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Advanced Member Group: Benefactors Posts: 2,030 Joined: 21-June 03 From: Miami Beach, FL Member No.: 848 |
I'm so glad we're switching to webers.
dr |
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| Bleyseng |
Mar 30 2004, 10:31 PM
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#10
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Aircooled Baby! Group: Members Posts: 13,034 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
(IMG:style_emoticons/default/agree.gif) 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 |
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| garyh |
Mar 31 2004, 12:01 AM
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#11
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Member Group: Members Posts: 170 Joined: 8-January 03 From: San Mateo, CA Member No.: 114 |
QUOTE(Bleyseng @ Mar 30 2004, 08:31 PM) (IMG:style_emoticons/default/agree.gif) with Bowlsby as using your mouth doesn't work. 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. |
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| Gint |
Mar 31 2004, 01:04 AM
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#12
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Mike Ginter Group: Admin Posts: 16,071 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
QUOTE What do I say if someone finds me sucking on a piece of my car? Just tell 'em that you really (IMG:style_emoticons/default/wub.gif) LOVE (IMG:style_emoticons/default/wub.gif) your 914. |
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