 Chasing a Ghost in the Machine, It’s been a year and I thought I had it. |
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| mgphoto |
 Feb 10 2026, 11:46 AM
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"If there is a mistake it will find me"  Group: Members Posts: 1,393 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California  |
About a year ago my usually good running engine began to stumble, slight backfire through the exhaust, between 1000 to 3000 rpm. I first suspected an electrical fault, as I would shake wires in the engine compartment and the issue would be gone.
This happened several times with different wires. I decided to tin the ends of the wires attached to the positive battery terminal. This seemed to work, for a while. I began testing other wires for the D-Jet, I had success with reattaching the TPS connector, for about a day. I began following a post about a member who had trouble with his 123 dizzy, his issue was related to the D-Jet pulse producing erratic fuel delivery. OK, spoke with the tech person at 123 in Europe, we could test it using an oscilloscope. I have a small pocket unit that I can test it with. This past Sunday I decided would be a good time do the test. My plan was to take the car out for a warm up drive, once around a freeway loop gets my oil temp needle to move. After exiting the freeway, I stopped at a traffic light and the car stalled, I’m used to that happening sometimes as I have a lightened flywheel, but this was different, like I turned the key off. I turned the key to restart the engine but it sounded like a rattling chain, I never heard that sound before. I tried the starter again, now it had the typical hot start problem, after a moment I got it to run but the idle was now at 3400 rpm. Since I could control it I drove it home and began checking simple things like throttle cable, TPS loose, MPS held some vacuum using the suck test. I’m going to take a closer look at the throttle body. Anyone have their D-Jet idle jump to 3200 rpm and what was the reason? Thanks, Mike |
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| brant |
Feb 10 2026, 11:50 AM
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914 Wizard Group: Members Posts: 12,136 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains 
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Return spring maybe
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| 76-914 |
Feb 10 2026, 12:14 PM
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,854 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California
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spot weld failure on the clutch cable tube? (IMG:style_emoticons/default/beerchug.gif)
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| Dave_Darling |
Feb 11 2026, 01:28 AM
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#4
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914 Idiot Group: Members Posts: 15,323 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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A 3200 RPM idle is an air leak. A *BIG* one. Check for hoses that have come off the manifold, then check for hoses that have come off other stuff in the bay. Look down the throttle bore to see if the throttle plate is jammed open or is damaged. Then check for stuff like holes in the plenum or a split plenum.
There's a reasonable chance that you have multiple problems adding together... --DD |
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