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) |
BeatNavy |
Oct 11 2016, 04:03 AM
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#2
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Certified Professional Scapegoat Group: Members Posts: 2,924 Joined: 26-February 14 From: Easton, MD Member No.: 17,042 Region Association: MidAtlantic Region |
First of all, I agree with DD - check your electrical connections and your charging system. I had a very slight hiccup at 3k RPM a few weeks ago that I think was slightly faulty connections at the common ground point (3 point ground at back of case). If those are not secure, you'll get fuel delivery interruption issues.
To check the CHT do several tests in whatever order makes sense to you: 1. Visually inspect the actual connection - check the lead to make sure it's connected securely connected to the wiring harness and that the connection isn't grounding out against case or other things around it (where the lead and wiring harness connect should be protected with plastic connector). Inspect the entire length of the wiring harness to ECU to make sure it's not kinked or breaking. If the connection is intermittently open, as with a failing wire, you may get symptoms like you're describing. Keep in mind the CHT lead may be wonky at the base, where you can't see it unless you remove the whole sensor, which can be a little tricky. 2. Disconnect CHT lead at wiring harness, and with Ohmmeter, check resistance from CHT lead to ground (e.g., negative battery terminal). When engine is cold, at ambient temp (e.g., 60 degrees), you should get in the neighborhood of 1500 to >2K ohms. With engine warm, you should get around or <200 ohms (check Anders's site for more info and specs: http://members.rennlist.com/pbanders/djetparts.htm). If you don't get acceptable readings, CHT sensor is bad. 3. Reconnect the lead to wiring harness. Disconnect ECU connector (25 pole plastic connector). Check continuity from Pin 23 in connector to ground. You should get the same readings as #2 above. May want to move harness around a bit while doing this to see if you have an intermittent break in the connection somewhere. Others may have more/better info, but again, this is a good reference: http://members.rennlist.com/pbanders/djetparts.htm |
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