This has been doing my head in since the beginning of the year. Most of you will say I have over complicated my setup and you are probably right. I run an electric pump with a twin relay system. The relays allow for the pump to run when starting but will cut if I stall / have an accident. This setup has been working for years and having an electric pump allows me to send a text message to my immobiliser which cuts its power. When trying to start, the engine turns over but doesn't fire until the point of releasing the ignition key. If I finally get it started, the engine runs fine and I have been driving about with no issues until I go to start again. Feels to me that the pump isn't running when cranking the engine. I have spent hours tracing all the connections to the relays, have replaced them, tested the old ones, checked the incoming voltages, earth's etc. If I pull the relay connection to the generator light I can hear the pump running and still no start. Then I started checking other things, I can see fuel being squirted down the carbs, cleaned up the cap and rotor then decided to swap out the electronic ignition and it started first time! What strange symptoms is this? As I said, it runs fine once started. The only thing it sounds like is a voltage drop while cranking and it is too low for the faulty ignition module and I get no spark. Moral of the story, if you are going to run cheap electronic ignition, always carry a spare! Sent from my Pixel 7a using Tapatalk
I thought so too but I was getting a good signal from it to the relays. Bus started fine again this morning where on the previous electronic ignition it didn't. I also have a hot start relay. Sent from my Pixel 7a using Tapatalk
You measured that with the starter churning? My Westy used to start first compression every time so when my ignition switch developed that problem I was able to drive for about a year like that. I knew what was wrong but still worked so...
No, but if I disconnected the generator light from the relays the pump would start, so this is correct. I could also smell fuel when kicking over. Sent from my Pixel 7a using Tapatalk
I'm still thinking ignition switch though. Mainly because I don't understand your explanation logic. Time will tell. You removed load from the switch for your test.
Worn switch is a classic, the engine fires because its still spinning when you release the key, at which point the ignition power comes from a different point on the switch contacts, which usually have a massive canyon worn in them by arcing when they fail. If you had an old style electronic ignition like the Ignitor 1 it doesnt need to adjust itself before firing. Newer electronic ignitions might need a couple of messed up firings to adapt their dwell angle before the engine would start by which time it has slowed too much. The switch may just about make contact for the tiny current from the test meter but "blow" when it has any real current draw. You could always check by bridging from coil plus to battery plus and see if it starts easier when you turn the key and crank..
What year is your bus? The later wiring that uses a multi plug to the bottom of the ignition switch You can pull the plug off and plug in a new ignition switch and use a flat blade screwdriver to turn the switch. Easy way to rest/rule out the switch Get a febi branded switch the other no brand ones don’t last long
72. So late bay rear and early front. I have the early indicator stalk and presuming early ignition. Sent from my Pixel 7a using Tapatalk
Micro magic flathead grubscrew time. Dont drop it as it is going to take a while to file down another screw to give it the smooth 'nose' it has that is a locking pin..
