---------------------------------------------------------- RV8-List Digest Archive --- Total Messages Posted Sun 01/17/10: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:24 PM - VDO erratic fuel pressure readings resolved (Vincent Himsl) ________________________________ Message 1 _____________________________________ Time: 11:24:03 PM PST US From: Vincent Himsl Subject: RV8-List: VDO erratic fuel pressure readings resolved Hello=2C This is followup to my inquiry about erratic high fuel pressure readings on my Dynon supplied VDO fuel pressure sender. To recap=2C I would have normal readings for about thirty minutes then my f uel pressure would slowly creep up to 9 or 10 psi=2C then start bouncing ar ound tripping my warning alarms (wakes you up quick). I do not have fuel injection but in my archive and google search came acros s those with the same problem only with higher PSI readings. Well=2C skipping the "I did everything perfect part"=2C the VDO fuel pressu re sensor comes from Dynon with mounting tabs already installed. You assume as I that these tabs are a match for the aircraft quality slide on crimps. They apparently are not. I removed and tossed these tabs and used a standard crimp connector instead (one with hole in it). Fuel pressure readings are now rock solid after two hour flight. Keep the nut and washers for use with the standard crimp thou gh (I think they're metric) and do not tighten too much as I/you don't know if too tight will change the sensor resistance. In my troubleshooting odyssey I used a scope meter (yes I got that desperat e) to determine if any electronic device save the ignition was affecting th e signal. The signal stayed rock solid. The radio would impress a millivolt high frequency signal across the sensor but there was no affect on the vol tage or displayed PSI. My take on the problem is that the tab crimp interface due to the mismatch would become intermittent when exposed to heat and/or vibration. I relay all this to help others avert a very long=2C frustrating search. Fr ustrating in that most of us won't fly with erratic fuel pressure readings. Now on to my tachometer accuracy problem. Vinch H. RV-8 'Flying' N8432 - 24 hours _________________________________________________________________ Hotmail: Trusted email with Microsoft=92s powerful SPAM protection. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv8-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV8-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv8-list Browse Digests http://www.matronics.com/digest/rv8-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.