79 bus no start after getting hot (again, diff starter)

[airkooledchris]

well, I did the first REALLY long drive since Maupin and the same problem I had on the way to Maupin plagued me today - once I stopped, it wouldn't start again.

this is a different starter/solenoid than last time this happened. not new, but a 'rebuilt' that I had from the PO.

I smacked the solenoid a few times, tried again, smacked a few times, tried again, but nothing was working so I had to push it and pop it the rest of the trip.

After stopping at a brewpub along the way and letting it rest for about 45 minutes, it still wouldn't try to crank over.

As of this post it's cooled off for 2 hours, and it's cold and wet out. Plenty of time to cool completely, but alas - it won't even try to crank right now.


other tidbits that may or may not factor into all of this...
1. The PO installed a push button start. you do have to put the key in the "on" position to actually start it, but the push button would always spin the starter (unless it's doing what it's doing now of course.)
2. I tried to install a "hot start relay" to aid in this issue, but when I tried it out the first time it made the starter continue to spin (from the sounds of it) even after I let off of the push button start, so it's disconnected.

3. I mistakenly left the vacuum advance line disconnected and plugged from the distributor on the way there. I reconnected it once I went to the engine compartment to check things over (when it wouldn't start) - and the engine ran a lot hotter on the drive home. On the way down I was hitting 420* at 65, but on the way home I had to back off to 55-60 to keep the head temps under 430*. The engine didn't feel strained at all, and I had to barely touch the throttle in order to maintain forward momentum but not push it any faster. Maybe it's just set to run too lean at almost no throttle. The drive down without the vacuum advance connected it didn't feel lacking in power at all.

Right now im just scratching my head about it all. Tomorrow I have off thankfully so I can start troubleshooting.

In no particular order, ill try
Smacking the solenoid once more
Disconnect and reconnect the cables on the solenoid
Scratch Buttocks
Bridge two connections on the solenoid to see if the starter CAN spin (will have to review this one, haven't done it personally, but it was suggested the last time this happened.)


btw, I was out scoping out good bus campout locations. we found 4 different beautiful spots to choose from. some along a river, some in the middle of a redwood grove, some with both in the middle of a valley. Lots of good options in Southern Humboldt, and thankfully I know a few promoters of events from around this area who have used all of these spots before.

Two of my favorite locations so far:

[dingo]

if you have a voltmeter handy, then a Volt-drop test is a good way to isolate a starter or electrical issue

http://www.excelauto.com/online/Tech.d/strvdt.html

http://www.youtube.com/watch?v=OIRnZNrBOw0


http://www.aa1car.com/library/voltage_drop_testing.htm

[airkooledchris]

In the end I bypassed the starter and just bridged the two large posts on the coil to see what would happen - and while the starter makes a noise, im fairly certain this means it's dead.

The starter doesn't make any different of a sound when you do this bridging of the solenoid than it does under normal circumstances right? My only confusion was Muir talking about bridging this to confirm the starter whirrs - and well - it's whirring, but in a 'that aint right' way.

Here is a video of what the starter is doing currently. I have a used one that was working when I pulled it - so im just debating on going through the R&R process on another potential POS or going and dropping coin on a properly rebuilt non-kragen style junker.

http://youtu.be/wWvnU0qvUog

[sped372]

If it whirrs it means the motor portion of the motor/solenoid pair is functioning, it's just rotating without the gear having been pulled into place by the solenoid. That's the purpose of that test.

[airkooledchris]

This was one of those 'lifetime warranty' units from probably Napa/Kragan/whomever, and not Bosch themselves.

I went down to my local VW specialty parts counter and they had a genuine Bosch made unit ready to go, so I dropped the money on a nice unit and hopefully I won't have to mess with it again soon. If I can track down a decent solenoid ill swap it out with my 'old' one to keep as a spare, since the starter itself is still working.


My Theory as to WHAT HAPPENED:

When I was under the bus I noticed that the passenger side dump tube hose was barely half connected to the heater control valve, so on that long drive when the heater was turned off it was just dumping all of that hot hot air a few inches away from the starter/solenoid. Obviously I can't say without a doubt that's what caused it, but that's my working theory since it worked fine until I went on a long drive with the heat off (I usually have the heater on all the time when putzing around town.)

I may throw in a big clamp to hold the heater hose in place to the heater control valve/dump tubes, so it doesn't rattle loose again and start causing more potential problems.

[Amskeptic]

My Theory
it was just dumping all of that hot hot air a few inches away from the starter/solenoid.

Even without the hose, the new heater valves are far better at getting exchanger air out from under the car. The earlier buses had bell exits that seriously aimed some at the starter.

Maybe . . . maybe it was just time.
Colin

[airkooledchris]

...and here I thought I had done some proper detective work.

*puts away corn cob pipe* - as you were my dear Watson

im off to replace the starter switch right now, even though the pushbutton is working.

my new theory as to the constant starter/coil issues is that the pushbutton start isn't giving the coil enough voltage, starving it, causing it to overheat, and burning it out early.

at any rate it'll be nice to get it all back to original operation, if nothing else, to eliminate these hokey workarounds as sources of other issues

[Amskeptic]

my new theory as to the constant starter/coil issues is that the pushbutton start isn't giving the coil enough voltage, starving it, causing it to overheat, and burning it out early.

Don't blame the switch. If it makes, it is unlikely be serving as a resistor unless it actually gets hot. The wiring and connections, maybe.
You might find a serious Itinerant Air-Cooled ground path enhancement seminar will open your eyes to just how nice a ground path can be . . .
Colin