I've been hunting trying to find other examples of this issue but haven't seen any, and I looked through the FSM and troubleshooting manual and can't find enough info, and I've read a ton of glow plug threads on here with nothing.
At startup, my 3B turns over fine, but it takes several hits of the superglow system to get it to start (pretty sure I have superglow, July 83 build, but would love a simple pointer on how to check). When it does start, it often dies right away unless I feather the throttle. Batteries are both good (12.5V). When it does get going, it runs pretty rough as if one or two glow plugs are bad. But when I check the voltage anywhere on the bus bar, it's showing 1.5V at the start, climbing to 3.5 by the time the timer shuts off. I think this low voltage condition is what's causing the rough start because the plugs aren't getting hot enough, but wondering if anybody can help me figure out why this might be happening. Took the pre heater circuit apart and nothing obviously wrong, followed the startup troubleshooting in the engine manual and the leads are behaving totally normal, so I know the switch is fine. I'm at a loss and am sure it's something simple that is escaping me.
At startup, my 3B turns over fine, but it takes several hits of the superglow system to get it to start (pretty sure I have superglow, July 83 build, but would love a simple pointer on how to check). When it does start, it often dies right away unless I feather the throttle. Batteries are both good (12.5V). When it does get going, it runs pretty rough as if one or two glow plugs are bad. But when I check the voltage anywhere on the bus bar, it's showing 1.5V at the start, climbing to 3.5 by the time the timer shuts off. I think this low voltage condition is what's causing the rough start because the plugs aren't getting hot enough, but wondering if anybody can help me figure out why this might be happening. Took the pre heater circuit apart and nothing obviously wrong, followed the startup troubleshooting in the engine manual and the leads are behaving totally normal, so I know the switch is fine. I'm at a loss and am sure it's something simple that is escaping me.