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MGB Starter - Non starter?

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Boggsy64

Boggsy64

Jedi Hopeful
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Feel like I'm on a treadmill running fast and not reaching the end! Now finally car all on the ground and after starting engine last weekend shut back down to replace the block to filter oil hose and repair radiator. All that is done but the engine will just barely turn over. Typical solenoid clicking etc (along with some smoke from where, nothing obviously hot??). Took out the battery and confirmed it is holding a charge, took the battery to Advance Auto to be sure and all is good. Cleaned the battery connections, checked ground to the block and all good (just replaced the transmission mount and ground strap is good). As I drove this thing from Arizona this summer I noticed the starter cranking getting slower and slower each day. I thought the battery must be going bad. Now it barely cranks, actual will not move now. Is it typical for these starters to slow down and eventually grind to a halt (Ha Ha!!). I am thinking brushes?
 
Sounds like you lost your grounds. Starters are normally pretty good. If it were brushes there would not be the solenoid clicking. Check to see if the throttle cable or heat temp control cable is getting hot. Use a set of jumper cables to ground the engine and see what happens. As a side note I would not use a new style hi torque starter on a later MGB. I have one here that keeps coming loose from the adaptor plate! I pulled it out and am running a original starter on the car now. Bob
 
The best way to check a battery is to charge it up with an external charger and do a load test. How did they guys at Advance determine that it was OK?

If you are confident that the connections are good (and it sounds like you are), and the battery checks out, it's gotta be the starter. Might be the brushes or some other internal connection. Fortunately, starters aren't expensive.
 
I had charged the battery several times with an "automatic" setting on the charger. Initially pulled about 7 amps (10 amp charger) and then rapidly drops off to zero. I took the battery out and charged again and same charge pattern. Tested with VOM and 12.7v. Advance put it on a small hand held tester and came up with 590CCA the battery is rated 650CCA, so OK. I have tested from the block to ground with VOM and getting full short so ground appears good. I will be pulling the starter tonight to see if the ground connection on the starter itself is loose or something. I don't know if simple VOM testing for grounded block is sufficient due to high current flow required.
 
bob67bgt said:
Sounds like you lost your grounds. Starters are normally pretty good. If it were brushes there would not be the solenoid clicking. Check to see if the throttle cable or heat temp control cable is getting hot. Use a set of jumper cables to ground the engine and see what happens. As a side note I would not use a new style hi torque starter on a later MGB. I have one here that keeps coming loose from the adaptor plate! I pulled it out and am running a original starter on the car now. Bob
Click to expand...

I'm with Bob on this one. Seen it too many times: faulty ground somewhere.

And on a side note, Bob, that happened to the one I installed on the TR3 I restored some years back.

Mickey
 
I would not pull the starter. Test grounds with a set of jumper cables. Could save a bunch of work. Mickey, Funny you should mention a TR3. I am painting mine now. Bob
 
Bob, I am with you..don't want anymore crawling around for a while. Problem is the starter has that vinyl or rubber cover so I cannot even get access to the wires under the cover. I figured the only way was to pull it out to get the cover off. Seems I would have to pull the clutch slave cylinder as well? Or do you have something else in mind, like directly connect the jumper cables starter case to frame?
 
Wow Bob is a master! After talking to bob he told me to use jumper cables to insure block grounded, and to watch out because the smoke I saw could be from the throttle cable being used by the starter as a ground path. Sure enough jumper cable attached to the block and other end to negative terminal of the battery it cranked like a champ! And sure enough the throttle cable now toast! At least I didn't waste time taking out the starter. Thanks Bob!
 
The number of throttle cables we've seen melted is in the triple digits by now. Even an under-hood fire or two as a result of poor or ~no~ ground strap (an instance with a Midget after a DIY clutch replacement).
 
well that makes me uneasy. where should i see a grounding strap on my 78 b?
 
The grounding strap is on the transmission / rear engine mount assembly. One end is captured by one of the bolts holding the rubber mount to the trany and the other end to the bottom (crossmember) side, under the nut. I had painted my used cross member really well after replacing the old one due to old damage. I guess the paint insulated too well. Cant get at the nuts and strap now that it is all back together and don't have the will to tear it apart again right now. I have ran a "temp" ground, using a short battery cable with eyes on both ends, from the engine mount to the frame. This will work until I get back under there in earnest!
 
thanks for the update. one more thing to check.
 
Last night found the starter had grounded through the braided steel flex hose, from the block to the hard line, for the oil pressure gauge as well. The line had passed over the metal end of the oil line going to the filter. I had found a serious leak there and thought is was the oil filter line. Turns out the braided steel line was "arc" burnt and the inside hose failed. The outer braiding is burnt and some of the wires welded! I guess another trip to the auto store or Moss. P.S. I think the cable to the heater valve is frozen as well. A lost ground is costly!
 
If you have a good hydraulics shop around: remove the ends of your leaker carefully, using a Dremel with a cut-off wheel, slicing the crimped "shield" in a couple places lengthwise. Take the ends to them and have an Aeroquip hose made up. $10 and out the door. Those fittings are BSP (British Standard Pipe) and most "hose houses" won't have replacements. I've had the ones from "the usual suppliers" fail rather quickly. To find a good shop, ask some local trucking firms.
 
Dr, Thanks. I tried to look up the fittings with no luck. Could not identify a fitting with an O ring inside that matched the profile. Good suggestion to get use of the old hose ends.
 
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