<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Radio interference might be possible as a cause. Perhaps at 3000 RPM the spark is causing a circuit resonance that unlinks at lower or higher RPMs. VW added a bracket to keep the plug wires away from the FI leads for a similar reason:<div class=""><a href="https://www.thesamba.com/vw/classifieds/detail.php?id=2421190" class="">https://www.thesamba.com/vw/classifieds/detail.php?id=2421190</a></div><div class="">Right side of this photo:</div><div class=""><a href="https://www.thesamba.com/vw/classifieds/pix/9027914.jpg" class="">9027914.jpg</a></div><div class="">The bracket needs some plastic HT lead holders, which are still available, too.</div><div class="">I think the Type 4s had the same issue.</div><div class="">So I’d make sure the HT leads are away from any FI wiring as much as possible.<br class=""><div class=""><div class="">Yeah, not too likely, but you’ve already eliminated the common causes!</div><div class="">-Phil</div></div></div></body></html>