QuestionQUESTION: My 1979 MGB has been running fine, up til yesterday. I was driving down the highway and it started jumping, then I couldn't accelerate. I downshifted and still couldn't get any gas to the motor, and eventually it died.
When I try and start it, I turn the ignition, and I hear nothing. I have heard a click a couple of times, but it is random and majority of the time I get no sound. The power on the inside doesn't seem to come on either, although I have basic panel functions like lights, wipers, etc.
I don't know if its the solenoid, starter, relay, or distributor. Or more. Thanks for your help.
-Michael
ANSWER: Hi Michael
The fact that the engine died while running rules out the starter motor. My immediate reaction is that the fuel pump has packed up. Normally, when you turn the ignition on but before you hit the starter, you should hear the fuel pump ticking a few times until it has filled the carburetters. On a 79 B the lid of the pump sticks out into the boot (trunk) underneath a black metal protective cover. Remove the cover and the lid of the pump, clean the points, and all should be well for a short while. In the longer term, you probably need to replace the points inside the pump, or to replace the pump with a reconditioned unit.
If it isn't the pump, get back to me.
---------- FOLLOW-UP ----------
QUESTION: Barrie,
Thanks for the quick response. I replaced the fuel pump about 3 months ago, but checked/cleaned the points anyway. When I turn the ignition, it doesn't engage at all. There isn't a click from the fuel pump or starter, I just turn the ignition and I get nothing.
Thanks!
ANSWER: Sounds like a faulty ignition switch to me. Switch the ignition on. Do you have a heater fan? Do the wipers work? If not, then there is a fault at the ignition switch.
I don't know how good you are at fixing faults yourself. You need to inspect the wires that go to the switch, which is plugged in to the rear of the steering column lock. It could be a wire has come loose, or it could be the switch itself has failed (they do).
The power supply coming in to the switch is a brown wire. Be careful, it is always live and not fused. Try jumping it to the plain white wires. The wipers and fan motor should burst into life. If you jump it to the white/red wire, then that should activate the starter motor.
Get back to me.
---------- FOLLOW-UP ----------
QUESTION: Barrie,
I haven't tried jumping the switches yet. I will tell you that yesterday while trying to diagnose the problem, I ran a volt meter across my battery posts and noticed that it was only getting 7.0 volts. I checked the starter solenoid and that was only getting about 3.5 volts. So, I jumped my car and it started. However, after leaving it running for about 10 minutes disconnected from the other car, it died. When I tried to start it, I couldn't.
So I checked the battery posts, and the voltage had gone back down. My battery is fairly new, but its possible it shorted out somewhere along the line and my alternator can't get through to it.
I will probably get a new battery, although the alternator may have some issues.
I will go and check the ignition switch.
AnswerI think you have found the problem. Your battery should show 13.5 volts. Beware that the alternator uses the battery as a reference voltage, so a bad battery can destroy a good alternator.
The starter has a remote solenoid to operate it, and this requires a good voltage or else the starter will not operate.
Also, I think by 1979 the accessories have another solenoid, hence they stopped working.
I would remove the battery and get it tested under load by a battery specialist.
