Mgb gt 1978 starting problem. Please help!!
Mgb gt 1978 starting problem. Please help!!
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Mgb gt 1978

Original Poster:

1 posts

161 months

Thursday 2nd May 2013
quotequote all
Hello,
I have a starting problem which is really baffling me and has been on going for about two weeks now.
Please someone help!!
Ok so it's a 1.8 mgb gt 1978, hasn't started in two years.
This is what I've done so far:
1. Replaced old battery with brand new 680 amp battery
2. Replaced old starter motor with a brand new starter motor
3. New negative lead running from negative battery to body. I also sanded down the body to make a good connection
4. Manually cranked the engine so I know it's not seized.at the same time poured some oil down where the spark plugs came from
5. Drained old fuel and replaced with £10 new fuel
6. Sanded down engine earth lead connections by the cross member
7. Fitted new points
8. Fuel pipe between carbs was perished so replaced with new one.
9. New fuel pump which now works when I turn the ignition on.

The problem is I only get a clunk noise when I turn on the ignition.
No turnover at all.
I'm completely baffled at what to do next.
Can anyone point me in the right direction before I kill myself!
Thank you

jimbob82

690 posts

164 months

Thursday 2nd May 2013
quotequote all
did you check the ring gear on the flywheel when you changed the starter?

annodomini2

6,971 posts

281 months

Thursday 2nd May 2013
quotequote all
Did you check the starter motor works on the bench before fitting it?

The Black Flash

13,735 posts

228 months

Thursday 2nd May 2013
quotequote all
Clunk means that the starter gear is engaging, but not turning. Either not enough power from the battery, something is jammed, the motor part of the starter isn't connected, the starter doesn't work.
I'd check that the engine turns over by hand (again), check the wiring to the starter, then try a different battery/jump start. If that fails, starter off, and bench test it.

Locknut

653 posts

167 months

Thursday 2nd May 2013
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You say you poured oil into the spark plug holes, how much oil? Was it enough to cause a hydraulic lock?

Take out the spark plugs again and try the starter to see if it spins. If the problem is too much oil in the cylinders it will be blown out through the plug holes so put some rags over them.

paintman

7,860 posts

220 months

Thursday 2nd May 2013
quotequote all
Fully charge the battery with a battery charger.
Connect a good quality jump lead directly from battery earth terminal to the engine block.
See what happens.
A common problem is plastic covered earth straps. Whilst the ends may look fine, the section covered by the plastic can corrode completely away.

davepoth

29,395 posts

229 months

Friday 3rd May 2013
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I had this problem on a '73, it was a bad earth. Earth the engine to the body with a jump lead onto a bare bit of metal, it should turn over like a good'un.

paintman

7,860 posts

220 months

Friday 3rd May 2013
quotequote all
I had a Scimitar. Most things are earth by wire smile. An extra earth lead direct from the block to the battery main earth cured a number of minor issues.
Earth issues of this type are also common on Land Rovers, again mainly due to not checking the earth straps. I've seen handbrake cables with the inner welded to the outer by the heat as that was the only route that the current could find - can also cause a fire, so worth checking!