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MG TD TF 1500 - Electrical issue trying to start 51TD

Well, first attempts failed. Good part; I'm getting 20psi oil pressure just cranking, without firing.
However, I don't appear to be getting spark. I *think* everything is OK with the wiring, coil and distributor, but a) no ignition light b) no spark c) ammeter doesn't show much of a drop; about -5a
Thoughts?
I've checked connections and wires, all looks good. For the life of me I can't remember if there was a strap grounding the engine, and I can't see one anywhere. Where would it be (if there is one?)
Thanks, suggestions welcome.
Geoffrey M Baker

Geoffrey the original strap would be on the bellhousing bolt then to the chassis on the left side. Should be right above the peddle box. Did you turn the key on? Don't ask...
Bill Chasser Jr

lol bill it will probably be something as silly as that. But yes, I've turned the key!
I'll check for the strap...
Geoffrey M Baker

Trying to remember if the ignition is fused - check fuses, anyway if its cranking it has an earth - unless it is shorting via a cable etc.
mog

Check the white circuit for 12 volts with the ignition switch turned on - good place to check is the primary connection of the coil. Next, make sure that the tach drive gear box has not rotated up against the terminal on the side of the distributor. Cheers - Dave
DW DuBois

A few questions before digging further.
1) There is a grounding wire on the body clamp bolt of the distributor. Where should that connect? I believe it was just connected to the bottom pivot bolt of the generator.
2) I found a wire while working which appears to have been connected at one point to point E on the control box. It routed through no loom or harness but passed through the battery box and connected to nothing that I could see. Connections to contact E look correct, with 3 wires, which I believe are are 2 grounds and a wiper motor wire. I've always assumed it was probably a wire for a cigarette lighter which used to be in the dash, or maybe an additional ground wire. Just hoping it wasn't something important. Color yellow.
Probably just a yellow herring :)
As far as I can see, all electrics work 100% - turn signals, headlamps, horn, starter, fuel pump (clickin away correctly), heater fan, dash lights.

Ammeter still doesn't show much of a draw... drops to -5 when I turn the lights on but sits ticking on zero the rest of the time while running the starter motor.

Dave, tach drive was close but not touching. I moved it to be on the safe side; didn't solve the problem.
Geoffrey M Baker

Another question, diagram shows coil wires as SB and CB. Which is + and which - on the coil, because my coil is marked plus and minus, not SB and CB...
Geoffrey M Baker

Have had this happen to me, and it recently happened to a friend's TD.
Both times they came alive after putting the Battery Tender on the car until it showed full charge. Fired right up!
You never know - we both swore that we had enough charge, and we figured if there's juice enough to turn the starter there should be juice enough for spark. Apparently not.

BobbyG
Bobby Galvez

Dave's site has good pictures of the ground as I remember.
efh Haskell


She started. The wire on the coil ballast was loose.
Once I tightened that up, she started immediately.
Geoffrey M Baker

This thread was discussed on 08/12/2015

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