Good News with DJet - Almost there!, Making progress... |
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Good News with DJet - Almost there!, Making progress... |
customstarr |
Jun 27 2007, 11:21 PM
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#1
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King of the Nighttime World Group: Members Posts: 116 Joined: 13-February 07 From: Waterford, Michigan - Home of Waterford Hills Road Racing Member No.: 7,531 |
I want to start by thanking everyone for the input & assistance - I still be totally fuched if it wasn't for this web site, and the people that are dedicated to the 914. Anders site on the DJET system is an unbelievable resource. The 914 community has to be one of the strongrest and most knowledgable of any that I've been associated with in my years of the car hobby.
Finally got to the bottom of my rich running D-Jet issues - saved the best for last I guess. Timing and trigger points - that's what made the difference. Trigger points were dirty & timing slighlty retarded (like me I guess.) In the quest to solve this, I replaced and/or checked everything. Here's where I'm at: Car is running good overall. It wants to die if I don't stay on the gas during the first 10 seconds of a cold start. After that, it runs stable with a low idle (500-600 RPM) - but it doesn't stall. I suspect a lean condition based on the info I've read. The idle improves as the engine warms, ultimately stabilizing at about 1K. Since this is an early system (early 71) it does not have the enrichment knob on the ECU, and it has a 4-Pin TPS. I can't find any info on how to test/adjust the 4-pin TPS. Wondering how I can verify ECU is recogizing idle from TPS (no method to adjust), and how to richen the idle? Toon has a 1972 FI system available- I'm wondering if I should switch to that to gain control over these things, or if there's a way to do it on mine. I haven't found that answer anywhere. |
Demick |
Jun 28 2007, 09:36 AM
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#2
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
It wants to die if I don't stay on the gas during the first 10 seconds of a cold start. After that, it runs stable with a low idle (500-600 RPM) - but it doesn't stall. I suspect a lean condition based on the info I've read. The idle improves as the engine warms, ultimately stabilizing at about 1K. If your idle is too lean, the idle speed will 'hunt'. In other words, it will not hold steady idle, but will constantly change from 500-1500rpm or so (without you touching the gas). If it doesn't hunt, then it is probably not lean. Your symptoms on cold start are typical for a non-functioning AAR (Auxiliary Air Regulator). I'd bet it's not working. There are several sources to read about it. Here's one: http://members.rennlist.com/pbanders/DJetParts.htm Scroll down until you get to the Aux Air Regulator section. Good luck. Demick |
customstarr |
Jun 28 2007, 10:12 AM
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#3
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King of the Nighttime World Group: Members Posts: 116 Joined: 13-February 07 From: Waterford, Michigan - Home of Waterford Hills Road Racing Member No.: 7,531 |
It wants to die if I don't stay on the gas during the first 10 seconds of a cold start. After that, it runs stable with a low idle (500-600 RPM) - but it doesn't stall. I suspect a lean condition based on the info I've read. The idle improves as the engine warms, ultimately stabilizing at about 1K. If your idle is too lean, the idle speed will 'hunt'. In other words, it will not hold steady idle, but will constantly change from 500-1500rpm or so (without you touching the gas). If it doesn't hunt, then it is probably not lean. Your symptoms on cold start are typical for a non-functioning AAR (Auxiliary Air Regulator). I'd bet it's not working. There are several sources to read about it. Here's one: http://members.rennlist.com/pbanders/DJetParts.htm Scroll down until you get to the Aux Air Regulator section. Good luck. Demick Thanks Demick - I just started another topic on the AAR. I do agree that the AAR is probably my issue. When I cold start the car, the idle raises and then drops & continues the fluctuation up and down until partially warm. When I pulled & plugged the AAR to Intake line, the idle stabilizes - albeit low, but stable. The idle improves to normal when warm. I was under the impression that the AAR would just stick open or closed, but mine seems to cycle open & closed. BTW - no vac leaks - tight as a whistle. And like I stated, pulling and plugging the AAR line & intake boot hole stabilzes the idle. YES!!! I'm getting there! |
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