D_jet trouble shooting question - car is home, journey continues, June, update- no more problem-- the fix was simple.... |
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D_jet trouble shooting question - car is home, journey continues, June, update- no more problem-- the fix was simple.... |
DRPHIL914 |
Dec 15 2014, 12:39 PM
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#1
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Dr. Phil Group: Members Posts: 5,767 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States |
OK. car has been in shop for the past week, and today Bob spent several hours on it but what he found was when the MPS is disconnected from the vac hose it will idle and run, but when it gets connected it goes immediately lean and dies, and will not run with that hose on there- the MPS holds Vac no loss of pressure, but that doesnt mean that its not bad.
1- i thought that if an MPS went bad it defaulted rich? but when this is getting vac it goes lean right away and dies. but it will run and idle with out the vac , the AF meter then shows 9.8-10.2 or so which is of course rich but not flooding out. so the question is why is it going lean when hooked up? when this issue started about 2 weeks ago, it had been running just fine and all of a sudden it quit running. 2. could there be another issue we dont see that would be making it way to lean other than the MPS? might need to test another MPS, my 2nd one i just bought from someone here and it has never been opened but will not hold vac (slowly looses vac pressure) so it probably need to be opened and re-sealed. not a good candidate to trouble shoot with. ------ FYI- 1975 d-jet 2.0. newer wiring harness , CHT is newish(replaced 2 months before this issue started and was running perfect at that time) |
brant |
Dec 19 2014, 08:40 AM
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#2
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914 Wizard Group: Members Posts: 11,625 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
Was that mps a brand new one?
Sounds jet exactly like the scenario I've seen previously Put Kent's mps in and verify your numbers get better Chris is right that your afr is still wrong. I'm betting you have adjusted the one in the car? Way off. If Kent's mps truly proves to the you good numbers. Then take the diaphragm from your good mps and rebuild your old one. I think there a something wrong with your new mps. I've seen this only once before. Carefully compare the two diaphragms and use nothing else. Maybe have Geoff calibrate it if you want it perfect |
DRPHIL914 |
Dec 19 2014, 02:25 PM
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#3
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Dr. Phil Group: Members Posts: 5,767 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States |
Was that mps a brand new one? Sounds jet exactly like the scenario I've seen previously Put Kent's mps in and verify your numbers get better Chris is right that your afr is still wrong. I'm betting you have adjusted the one in the car? Way off. If Kent's mps truly proves to the you good numbers. Then take the diaphragm from your good mps and rebuild your old one. I think there a something wrong with your new mps. I've seen this only once before. Carefully compare the two diaphragms and use nothing else. Maybe have Geoff calibrate it if you want it perfect The one that got me home was one i picked up a few years ago that was opened up and revealed by someone else at some point. It holds vac good. Epoxy plug was taken out so at some pint I had it sent to Scott to set to factory settings. Had not use it until now and it appears that the factory settings are lean on my car. Scott used a LCR set it up. |
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