 D-Jet Light Stumble, Partial throttle only... |
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| GregAmy |
 May 27 2019, 07:02 AM
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Advanced Member  Group: Members Posts: 2,508 Joined: 22-February 13 From: Middletown CT Member No.: 15,565 Region Association: North East States 
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Here's an interesting one.
1974 2L D-Jet. Tangerine-rebuilt and -adjustable MPS (could prob use professional tuning). TPS replaced 3 or so years ago and properly adjusted (to the best I can with a couple alligator clips and an audible ohmeter). Pertronix electronic points; stock untouched D-jet plate. Injectors are all untouched though I've checked thoroughly as I can for vac leaks, nothing found. I'm getting a light stumble at cruise, but only at partial throttle. It never DIES, it's just a light misfire for a cylinder or two, seemingly at random, and not constantly. It seems to go away when I floor the throttle (and release that somewhat-less-than 90 poines of fury) and it's under a hard load. It's initially imperceptible to my passenger (wife) but I can feel it. The longer the cruise goes and the warmer the engines gets, the more prominent the stumble gets - never "bad" - to the point where my passenger (wife) will say "yeah I felt that one" but probably only because she was listening for it. The car never dies. Starts, runs, idles fine (after getting past the CHT donut hole). Possibly related: poor fuel economy - low to mid 20s - but I've put that down to not driving it a lot (evaporation) and as noted I've not properly tuned the MPS (giving thought to adding an AFR to the car). Thoughts? Easy things to check? As soon as Chris gets the racecar engine done and that project is completed, I'm planning to remove the street car drivetrain and go through it, including replacing intake hoses, lines, seals. Might even get the injectors serviced by Marren. Until then I'm still driving it around... GA |
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| GregAmy |
Jun 4 2019, 06:59 PM
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Advanced Member Group: Members Posts: 2,508 Joined: 22-February 13 From: Middletown CT Member No.: 15,565 Region Association: North East States
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Factory Work Shop Manual. Usually "FSM" (Factory Shop Manual). Of course, almost no one really has one of those...
BTW, drove it to/from work again today. Engine is butter smooth. Co-workers are like, "what is it?" and "how old is it?" and "is it a manual?" Now to figure out how to get rid of the harmonic wheel shaking at certain highway speeds. I think it's because of the non-hubcentric Panasport wheels. And the speedo needle bouncing between 5-40mph is annoying... |
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Posts in this topic
GregAmy D-Jet Light Stumble May 27 2019, 07:02 AM
JeffBowlsby Lube the dizzy weights once a year per the FWSM if... May 27 2019, 08:25 AM
jagalyn
Lube the dizzy weights once a year per the FWSM i... Jun 4 2019, 06:50 PM GregAmy Nope, I wasn't aware of that requirement. I do... May 27 2019, 08:51 AM JeffBowlsby Center of dizzy shaft...its hollow and direct cond... May 27 2019, 08:53 AM GregAmy ...that was easy... May 27 2019, 09:14 AM GregAmy Ok, so today was the first time I had a chance to ... Jun 3 2019, 06:22 PM Bleyseng The weights stick so your timing advance is sticky... Jun 3 2019, 06:46 PM JeffBowlsby Ah the power embodied in mere drop of oil in the r... Jun 3 2019, 06:47 PM rhodyguy Willing to bet back in the day that could have bee... Jun 3 2019, 06:51 PM 914_teener There are pivot points inside the dizzy for the ad... Jun 3 2019, 06:55 PM 914_teener On second thought....after reading you post...can ... Jun 3 2019, 06:59 PM GregAmy Of course! Distributor advance weights...I was... Jun 3 2019, 08:16 PM |
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