77 Bus - High Voltage

[buck]

77 Campmobile 2 ltr FI - Bus was running good. Last weekend took a trip (75 total miles) @ about 50 miles starting getting hesitation (feels like lack of fuel) when I let off gas pedal while running about 60mph. Return trip revealed same symptoms. I recently replaced battery because it woudn't stay charged (FLAPS guy tested it, claimed it had bad cell). When I got home I checked battery voltage and meter read 15.2 w/ engine off. Checked again today and w/ engine running meter measured 16.4 volts. My guess is voltage regulator has failed. Alternator is pumping to much juice to the battery and electrical systems causing ECU act up and thus the hesitation. Any ideas from the resident experts?

Buck

[dtrumbo]

Sounds like you've nailed it. Given your evidence and the relative ease of replacing the regulator, I say go for it. Your ECU, battery and everything else that is electrical in your bus right down to your bulb filaments will thank you!

[Amskeptic]

77 Campmobile 2 ltr FI - Bus was running good. Last weekend took a trip (75 total miles) @ about 50 miles starting getting hesitation (feels like lack of fuel) when I let off gas pedal while running about 60mph. Return trip revealed same symptoms. I recently replaced battery because it woudn't stay charged (FLAPS guy tested it, claimed it had bad cell). When I got home I checked battery voltage and meter read 15.2 w/ engine off. Checked again today and w/ engine running meter measured 16.4 volts. My guess is voltage regulator has failed. Alternator is pumping to much juice to the battery and electrical systems causing ECU act up and thus the hesitation. Any ideas from the resident experts?

Buck

Run the surface charge off the battery by keeping the headlamps on engine off for about 10 minutes. Check voltage. Start engine. What is voltage now? Report here.
Colin
(I'd like that old regulator)

[dingo]

new Volt reg. may or may not solve it..keep the receipt. If it doesnt, its most likely a bad ground (on Bosch systems)...and if not that, then look into the true status of your battery i.e. after removing the surface charge

[buck]

Jeez Louise, I am embarrassed to admit that I made a mistake in diagnosis of electrical system. My multi-meter had a low battery and was giving me an incorrect reading (high by 10- 15 percent). I should have checked against a known source. Battery and charging system check out and are AOD. So, hesitation problem still exists. Another sympton the bus is experiencing is when turning key to start position starter does not immediately engage and a slight whirring noise can be heard. Time elapse is approx 1 second. Prior to this problem starter engaged immediately when key was turned to start. Any ideas?
Buck

[satchmo]

Jeez Louise, I am embarrassed to admit that I made a mistake in diagnosis of electrical system. My multi-meter had a low battery and was giving me an incorrect reading (high by 10- 15 percent). I should have checked against a known source. Battery and charging system check out and are AOD. So, hesitation problem still exists. Another sympton the bus is experiencing is when turning key to start position starter does not immediately engage and a slight whirring noise can be heard. Time elapse is approx 1 second. Prior to this problem starter engaged immediately when key was turned to start. Any ideas?
Buck

Make the electrical connections on your starter shiny and clean. Do the same for the battery ground strap and any other ground connections you can find. Once you have done that, see how it starts and runs, and go from there.

Good luck, Tim