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MG MGA - starter problem

Hi
I have just fitted an 1800 in my MGA. I also have a new MGA starter. Problem is when the car is cold it turns over just fine. Once the car is hot the starter will engage but is very hesitant to turn the engine over. Sometimes taking a few tries to get it to turn over enough to start. Is this a compression problem with the larger engine or a resistance problem in the cables. I am neg. ground and have a cut off switch on the pos. side in line to the starter.
HELP
Kris
Kris Sorensen

Hi Kris. You might want to check your ignition timing to make sure it is correct. If it is out, the engine can be very difficult to crank, especially when hot. I believe early MGB starters were identical to MGA starters, so the starter motor should not be an issue cheers! Glenn
Glenn

Make sure your battery is good. Make sure all the connections, including grounds to the body are clean. Make sure you have an engine ground strap. Try it without the switch in the circuit, that might be bad. Be sure to remove the ground cable from the battery when you do the work, so you don't weld something or run over something. Always hold the nut behind the cable lug on the starter when you tighten the big cable there. If it turns, you may short the field coils to ground (ask me how I know), causing an intermittent or inoperative starter.
Tom

I agree with Tom. Let your fingers be your guide. Feel the various connections. The one(s)that are warm will most likely be the culprit. I was quite surprised at how much differe cclean metal to metal connections make. Especially the one at the starter itself.
Doug
D Sjostrom

My first thoughts were too far advanced ignition, then I saw Glen's reply so I second his opinion.

Steve
Steve Gyles

My 0.02c worth.

I too have an 1800.
I found if I directly connected the two starter cables together with the battery disconnected it would turn over very fast. ...
****Warning***
Big spark at the battery end when you do this...

I was doing this to get oil pressure for the first time, before starting a new engine.

So I though... Ah.... get a new solenoid... so I did from Moss UK... the problem improved, but not substantially.
I have seen on Barney's site problems with these solenoids though... melting down... not pretty.

I've seen inside MGA and MGB solenoids and MGA's have a much bigger contact area, so the resistance should be less.

Also the battery cables themselves can get old and cause more resistance, also if your using a modern single 12v battery, some gain can be made by upgrading this cable to a thicker one.

Engine earth strap is a must too...
Use jumper leads as an extra earth if your not sure.

Hope this helps...
<MARK>


Mark Hester

If we are talking about making sure all the circuit contacts are good then I would have expected Kris' problem to manifest itself when the engine resistance is high - engine cold.

Under my scenario, starting from cold, it takes a finite time for the fuel oil mix to get into the combustion chambers and for the engine to fire. When cold, this mixture is fuel rich (choke) and takes a while to explode, allowing the motor to fire correctly even though the ignition is too far advanced

When hot, the system is already primed and, at the first attempted rotation of the engine, a cylinder fires (early because of pre-ignition) and stalls the rotation.

Steve

PS. What are your running temperatures like? - see thread on 'All out of ideas - overheating'
Steve Gyles

Hi Guys
My running temp is 190. Engine starts easily hot or cold. Just that when it's hot the starter doesn't want to turn the engine over. If I can get one decent rotation it will start. I will try to bypass all the conections and use jumper cables from battery to hot side of solonoid and see if that makes a diference.
Thanks
Kris
Kris Sorensen

Sounds like exactly the problem I had.
Stalled in traffic once.... heavy London traffic and would not go... had to push start it... not easy when surrounded by unhelpful euro boxes...
I was going to hit the old solenoid with a big hammer once I replaced it... but It was weeks later and I had calmed down by then.

Good luck...
Mark Hester

I still say it's ignition timing and, as a consequence, you are running too hot. My 1800 sits at 170 even in temperatures of 30+.

Steve
Steve Gyles

I have always run at 190 even with the 1500. Don't understand how timing would affect the starter turning over the engine?
Kris
Kris Sorensen

If the timing is too far advanced, it will cause the engine to kick back making it hard for the starter to turn the engine. A quick test is to try running the starter with the key off. If the starter turns quickly with the key off, and bogs down when the key is on, then it is probably timing.

Jeff Schultz

Jeff, that's something I never thought of trying, thanks! And Doug, that is a very good way to tell where resistance is..feeling heat at the connection soon after trying to start. I think I'll go out and put some oil on the shaft of my starter now....and a bit in the generator while I'm there. These new cars spoil us so much.
Tom

Problem solved
Turned out it was a corroded ground wire at the battery. It looked fine utill we took it apart and it was not in great shape. Looks can be deceiving. Thanks for all your advise and help.
Kris
Kris Sorensen

Ah well, that's my theory out of the window!

Glad you sorted it.

Steve
Steve Gyles

Steve
Your theory is still valid but I knew the timing wasn't that far off to cause kickback so we kept looking till we found the culprit.
Kris Sorensen

This thread was discussed between 30/06/2005 and 05/07/2005

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