View Single Post
Alan L Alan L is offline
Registered User
Alan L's Avatar
Join Date: Apr 2006
Location: New Zealand
Posts: 3,249
I have found the cause, after a bit of frustration, just not sure how to deal with it.
Firstly, this would normally be a difficult issue to diagnose - so I will post some information here with some key words that would help others searching for similar issues. I was 'lucky' in that I could see the problem - the caps were off the relays for P1 & 2, by previous owner - so obviously he was struggling with this one too. Knowing what was happening - I can describe some symptoms which would otherwise lead you everywhere but to the problem.
The engine was rough starting. It would fire, cough, die, fire , cough die.....
Finally when it did get going, it was idling fairly sluggish and definitely too rich after a minute or two (the plugs were sooty black). The revs would also climb on idle. Over time it got faster and faster. The most tell tale sign of the relays oscillating was the low voltage at the AAR and WUR - consequently all the tuning was out of wack, and the AAR was not closing.
When I went to check the switch and plate settings, they were fine. The switch is opening as soon as the plate moves, and on idle the plate is open by about 1 mm - ie about 10 x what it took to trigger the switch.
So, I ran it again, and it went fine. Curse.
Put everything back and ran it again, and it went fine, until after a minute or two I could see the relays start to oscillate. While it was still running in this mode, I pulled the airfilter off and could see the problem - the air plate is vibrating furiously. If I stop it with my finger , it sits there steady and happy.
As soon as I blip the throttle , on closing, it oscillates again, and consequently so do the relays.
What the hell do I do with that?
Old 11-27-2007, 06:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)