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: 5,766 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) |
JeffBowlsby |
Jan 24 2015, 08:15 PM
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#2
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914 Wiring Harnesses Group: Members Posts: 8,502 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
Could it be an electrical connection? Harness issue? Corroded wire terminals or cracked/broken wires?
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DRPHIL914 |
Jan 24 2015, 08:56 PM
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#3
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Dr. Phil Group: Members Posts: 5,766 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States |
Could it be an electrical connection? Harness issue? Corroded wire terminals or cracked/broken wires? Jeff, To me it acts like a short or bad connection, like the f.i. Grounds are not tight I once had one come off and thats what it felt like. But it's not that. And the harness I got new from you 2 years ago and my mechanic when thru each circuit last month and double tested every one of them and I'd course at that time we found the bad mps which we swapped out and it ran fine. It didn't do its little trick until I got it home. Did that before I took it over and after I got home a week later. new optima battery no corrosion. I have not found any cracked or broken wires. After this started I replaced the circuit board and rear relay board. I guess it was not those as I did not get rid of the issue. I was thinking it could be a plug wire or the cap. I've heard ts of that happening so I might swap those out and see. right now I am sitting in it in the driveway. Perfect idle at about 1000, no hesitation at all. It's about 45 out . Will be interesting to see if it fires up in the morning. But while it's running I'm going for a short drive now . (IMG:style_emoticons/default/smile.gif) |
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