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MG MGB Technical - 77 B DIED @ WON'T START

I purchased a 77 B that had been in storage for about 14 years. After rebuilding the carb and hooking a temporary fuel tank it started right up. I then proceded to to install new fuel tank, pump, lines, etc, rebuilt cooling and hydraulic systems. I started it again today for the first time since (6 months) the initial start up. Started right up and was running fine for about a minute and died. Now it will not hit at all, does not appear to be firing and the ignition light is not illumenating when the key is on. The car still has the opus distributor in place. ( I could not believe that it actually worked)This is my first expierience with B's equipped with electronic ignition. If the opus has died, I would also like some opinions on options. One option is the petronix conversion for the existing distributor or install an earlier distributor. I eventually wish to install twin SU's and pre a 75 exhaust manifold. I think I would like the earlier dist but which petronix and what about the ballasted coil? What changes in wirng would be required? Any input greatly appreciated.
Scott
Scott Shirk

Scott. The fact the ignition light is not on tends to indicate that no power is present when the key is turned to the run position. I think this is the white wire circuit which includes both the fuel pump and the ignition relay. Does the car crank over? If it does, it there is a good chance the white wire circuit is at fault. As to aftermarket ignition systems, get a good points type dizzy and install it. They are much easier to trouble shoot than the "electronic ignition" systems. Once you get your car truly sorted, then, consider which form of electronic points replacement system might be of use. In the mean time, check for spark at the coil lead and let us know what is happening. Les
Les Bengtson

Scott

This happened to me last week. I cleaned up the connectors on the starter solenoid, one from the +ve terminal of the battery and the other two brown circuit wires. Used some fine emery paper to clean them up a bit. Used a brass wire brush on the threads of the stud and nut. Fixed the problem.
Richard Evans

I had a similar problem and it turned out to be the starter solenoid switch, mounted on the passenger side fender well. The car would start usually, then wouldn't, until it got to the point where it wouldn't start. There are threads in the archives on how to check.
Good luck,
Randy Olson
1977 MGB
randy olson

Thanks for the responses so far. The car is cranking over fine and I appear to have power through the ignition switch as the fuel pump is clicking and the radio etc are coming on. The distributor does not appear to be firing. I have cleaned the 3 terminal connector, rotor, and cap. I also connected my timing light to the plug wires and got nothing. I have not checked for voltage to the 3 terminal connector or checked the coil HT line yet. Any additional thoughts?
Thanks, Scott
Scott Shirk

Check you have 12v on the white, white/blue and white/black wires going into the Opus ('opeless) unit and also the white/green at the coil. If you do then the trigger or amplifier is probably dead. If not you have an open circuit somewhere.

If it is the Opus then assuming you can mount a pertronix in there that is probably the quickest solution, just disconnect and insulate the three wires going into the distributor and connect the two wires from the Pertronix to the coil - right way round. If the Pertronix won't fit the Opus you will have to get another distributor if it can't be modified, although you may well find that you can fit the points plate from any old 45D and retain the rest of the internals, cheaper than having to get the full works of the right spec for your engine. Changing the ballasted coil to a non-ballasted is probably a bad idea, the present system gives a boost to the coil voltage and hence spark during cranking, you would lose that.
Paul Hunt

This thread was discussed between 10/06/2002 and 11/06/2002

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