 MPS mystery, huh |
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| r3dplanet |
 May 1 2013, 11:07 PM
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Senior Member  Group: Members Posts: 679 Joined: 3-September 05 From: Portland, Oregon Member No.: 4,741 Region Association: None  |
Last winter I had some fun rebuilding my MPS unit, which is for a '73 1.7 liter engine. The MPS part number ends with 049.
According to the calibration tests on the pbanders website in conjunction with my trusty Meterman LCR55 and MityVac, the unit is perfectly calibrated. It holds vacuum without issue. The readings at 15, 4, and 0 in.Hg all match perfectly. And I mean perfectly. No variation from what the LCR55 shows to the pbanders table. The mystery is that when I hook it up to the car the engine won't start. It tries to start and I can sort of force to keep going by blipping the gas, but it won't idle on its own. However, when I install another verified trashed out unit, the car starts right up and idles and climbs smoothly. Um. Huh. I'm hoping that there's some other adjustment elsewhere in the system that my tired brain won't remember. Somehow maybe my car is adjusted to work around the (leaky) old MPS? Or maybe I didn't rebuild the MPS correctly. But it was in and out of the thing for days and I'm convinced the physical operation is correct. But I'm always willing to be wrong. Confused. -m. |
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| JeffBowlsby |
May 1 2013, 11:41 PM
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914 Wiring Harnesses & Beekeeper Group: Members Posts: 8,974 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None 
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The calibration values need to be indexed for atmospheric pressure based on elevation from sea level. And is that the correct meter, seems to me its not 'Meterman'
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| r3dplanet |
May 1 2013, 11:55 PM
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Senior Member Group: Members Posts: 679 Joined: 3-September 05 From: Portland, Oregon Member No.: 4,741 Region Association: None |
I was hoping you would chime in.
The Meterman is a Wavetek. Wavetek is the manufacturer, Meterman is the model. Also, I live at 1017 feet above sea level so I don't think I should have to reindex the values. The pbanders values were taken at 1280 feet. It should be close to enough to start and run the car to my mind. Good thinking though. -marcus QUOTE(Jeff Bowlsby @ May 1 2013, 10:41 PM)  The calibration values need to be indexed for atmospheric pressure based on elevation from sea level. And is that the correct meter, seems to me its not 'Meterman' |
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Posts in this topic
r3dplanet MPS mystery May 1 2013, 11:07 PM
brant This is the 2nd time I've seen this happen
I ... May 1 2013, 11:17 PM
Jeff Bowlsby
I was hoping you would chime in.
I would run t... May 2 2013, 09:37 AM cary What all did you do during the rebuild? May 2 2013, 05:56 AM stugray I have never messed with one of these things, but ... May 2 2013, 10:32 AM Jeff Bowlsby
I have never messed with one of these things, but... May 2 2013, 11:26 AM cary I did mine in Forest Grove.
Same meter and same r... May 2 2013, 10:48 AM stugray Jeff,
I just read the documentation that Paul And... May 2 2013, 01:54 PM larss
Jeff,
I just read the documentation that Paul An... May 3 2013, 11:20 PM 76-914 :popcorn: May 2 2013, 09:20 PM Jeff Bowlsby Hey Stu,
Sounds like you are deeper into the theo... May 2 2013, 10:39 PM rdauenhauer Geoff..? Yo Geoff you out there? May 2 2013, 10:41 PM Travis Neff The diaphragm is probably fine, you probably have ... May 2 2013, 11:20 PM Derek Seymour sound strange I know, but have you looked at your ... May 2 2013, 11:26 PM stugray
No, what I mean is that you would inject a sinus... May 3 2013, 07:19 AM brant there are 3 different models of CHT's each wit... May 3 2013, 07:48 AM |
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