MGB 1975 MGB Won't Crank

[Daddio1975]

Hello.... My first post and I'm already looking for help.

I have an ongoing issue with my MGB. To simplify, there doesn't seem to be enough juice to crank. If I boost it it works... but still cranks slow... or seems laboured.

I've replaced the battery and know it's good. I've replaced the ground and positive leads and ensured they are good. I found a current draw and have eliminated that.

When I test at the battery I get 12.8V. When I test at the starter positive terminal, I get 12.7V. When I test off the other post I get 0V and when I crank I get 11.3V.

The original starter was just replaced. I was having the same issue with it.

Is there something else I should be looking for? I can't trust taking this car anywhere as I know once driven, I have about 10% chance that it will crank.

 

[Kimberly]

The following links regard a similar problem. Keep in mind, new parts aren't always good parts.
https://www.mgexperience.net/phorum/read.php?1,811201,811201#msg-811201
https://www.mgexperience.net/phorum/read.php?1,817236,817236#msg-817236

 

[Daddio1975]

I've read the posts and will see what I can find out regarding a new starter. I'm really frustrated as I purchased this from a great MG shop. I would think they would have warned me when I told them the issues.

Now I have to start looking for a new starter. Anyone in Canada know an good place to get one?

 

[jlaird]

Try advance auto if you have one.

 

[Kimberly]

I've read the posts and will see what I can find out regarding a new starter. I'm really frustrated as I purchased this from a great MG shop. I would think they would have warned me when I told them the issues.

Now I have to start looking for a new starter. Anyone in Canada know an good place to get one?

You stated that you just purchased the starter. Is it under warranty? Will the shop exchange it?
What are the chain auto parts stores called in Canada? Go to their websites. If they don't list the part on their website, then call them.

 

[Billm]

I would really recommend verifying your ground connection from the engine to the chassis and battery to the ground, engine/chassis particularly.
Before buying anything else I would run a (big)jumper wire from the engine to the battery negative and try it then.
Bill

 

[Daddio1975]

I would really recommend verifying your ground connection from the engine to the chassis and battery to the ground, engine/chassis particularly.
Before buying anything else I would run a (big)jumper wire from the engine to the battery negative and try it then.
Bill

As part of the diagnostics of this problem I ran jumper cables directly to the starter. The result was the same.

 

[WA1KWA]

Does the throttle cable get warm when you try to crank the car for an extended period? If so, that's a dead giveaway your engine ground strap is missing/disconnected or otherwise not making good contact.

Is it an even, albeit it slow, cranking speed? If it is uneven, you may have a compression imbalance or cam timing issue.

Any automotive electrical shop should be able to test that starter. There's nothing special about it. Many jobbers can, also. Maybe even Canadian Tire.

After all, if you can't get it at Canadian Tire.......

Colin