 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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| cary |
May 2 2013, 05:56 AM
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Advanced Member Group: Members Posts: 3,900 Joined: 26-January 04 From: Sherwood Oregon Member No.: 1,608 Region Association: Pacific Northwest 
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What all did you do during the rebuild?
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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 The calibration values need to be indexed for atmo... May 1 2013, 11:41 PM
r3dplanet I was hoping you would chime in.
The Meterman is ... May 1 2013, 11:55 PM Jeff Bowlsby
I was hoping you would chime in.
I would run t... May 2 2013, 09:37 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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