Diagnosing an intermittent D-Jet problem..., Hesitation under load at 2800 RPM but only when cold... |
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Diagnosing an intermittent D-Jet problem..., Hesitation under load at 2800 RPM but only when cold... |
MikeInMunich |
Oct 10 2016, 02:46 AM
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#1
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Member Group: Members Posts: 392 Joined: 19-November 13 From: Munich, Germany Member No.: 16,674 Region Association: None |
Hi again from Munich!
Here are the details. But please see update from Feb. 5th below! I have a D-Jetronic intake. Under load and at about 2800 RPM Im experiencing an intermittent hesitation. Yesterday my son and I took the car out for a drive from Munich, towards Innsbruck and back and we ran into a bit of rain coming along the Aachensee (lake), and this hesitation got worse. Then I remembered the only other time I've had this car out with 100% humidity and that it wasn't running well on that day either, so this is apparently a clue. So what can this be? And why does it happen at all, even when it's not raining, albeit not as noticeably? Is there a cure? Experts / senior gurus out there, thank you for your time and sharing your knowledge and experience, in advance! With kind regards, Mike in Munich (IMG:style_emoticons/default/smilie_flagge6.gif) |
MikeInMunich |
Feb 5 2017, 12:55 PM
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#2
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Member Group: Members Posts: 392 Joined: 19-November 13 From: Munich, Germany Member No.: 16,674 Region Association: None |
Update, edited!
Unfortunately I don't trust the guy who installed the replacement TPS plate I got from Dave Sprinkle. The hesitation still persists. Also, when the engine is cold and I turn the knob on the ECU there is NO CHANGE to the idle speed at all. According to Mr. Bowlsby's posting about the system, this is an indication that the TPS isn't functioning or isn't adjusted correctly. As mentioned above, I measured the resistance at the CHTS connector to be > 2000 at ambient temperature (summer, ca. 25 C) and under 300 Ohms when the engine was warm. When the hesitation is happening, under load at about 2800 RPM it doesn't persist when I take my foot off the pedal. Another hint is that it ceases to occur all but 100% after the engine is FULLY warm. What do you think? Thanks, M.i.M. |
Bob L. |
Feb 15 2017, 09:41 AM
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#3
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Senior Member Group: Members Posts: 847 Joined: 7-August 11 From: Austin TX Member No.: 13,411 Region Association: Southwest Region |
Update, edited! ... Also, when the engine is cold and I turn the knob on the ECU there is NO CHANGE to the idle speed at all. According to Mr. Bowlsby's posting about the system, this is an indication that the TPS isn't functioning or isn't adjusted correctly. M.i.M. As far as I know, the knob on the ECU adjusts the fuel mixture not idle speed. Mr. Bowlsby probably knows something about this that I don't. |
JeffBowlsby |
Feb 15 2017, 09:50 AM
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#4
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914 Wiring Harnesses Group: Members Posts: 8,520 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
The ECU knob is a fine adjustment to fuel mixture AT idle. It has no effect off idle.
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