BJ8 Doesn't want to start when hot

[Wana]

Hi all - just joined the party and it's my first post.

I just got my Healey 4 days ago after wanting one for the last 30 years - my Dad bought one brand new in 1967 and sold it when I turned 16 in 1974. Swore I'd get one some day and that day has come! Now to my situation:
The car starts great from cold and runs beautifully. However, if I stop and shut it off for a few minutes it is almost impossible to get it started again. It will try to crank over once or not at all. Seems to get better after about 2 hours of sitting, but not before. Any ideas?

 

[Keoke]

\
Hi Wanna, welcome to the club.It just may be that the charging system in the car is maginal.Either the generator may not be putting out fully or the voltage regulator needs cleaning up or replacing. There will be other suggestions coming along soon.---Keoke

 

[AndrewMawson]

[ QUOTE ]
Hi all - just joined the party and it's my first post.

I just got my Healey 4 days ago after wanting one for the last 30 years - my Dad bought one brand new in 1967 and sold it when I turned 16 in 1974. Swore I'd get one some day and that day has come! Now to my situation:
The car starts great from cold and runs beautifully. However, if I stop and shut it off for a few minutes it is almost impossible to get it started again. It will try to crank over once or not at all. Seems to get better after about 2 hours of sitting, but not before. Any ideas?

[/ QUOTE ]

Sounds like an electrical problem in the starter motor wiring. I had a very similar problem and it turned out to be the battery isolator switch.

When cold some contact somewhere makes reasonable connection, but as it warms up metal expands and the contact is not so good. Check the isolator switch and the terminals on the starter relay and back of the starter motor itself.

This is also a symptom of worn starter motor brushes (the body of the motor warms up and gets bigger, increasing the gap between the commutator and the brush holder - if the brush is on it's last legs the spring cannot push it far enough.

/ubbthreads/images/graemlins/england.gif /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif

 

[Dave Russell]

I think Andrew may be pretty close. A good starting point at least. One of the most common starting problems is the battery ground switch. You can bypass this notoriously unreliable switch by moving the ground strap from it's large terminal to the other large terminal that goes to the battery. (The ground strap & the battery cable both on the battery cable terminal.)

Other possibilities are that the connections of the battery terminals are corroded, actually lead oxide, & not making good connection. It's not hard to clean all connections, both ends of the cables, with emery cloth or a stiff wire brush, coat them with a no-corrode-grease & retighten. Vaseline is ok if nothing else is available.

If you have the original "helmet" type battery connectors, they rely on a tapered fit of the sides to make good contact. Over time, corrosion & stretching of the connectors can cause a loss of contact with the sides of the posts so that only the very top of the post is making contact. The top alone cannot carry the necessary current. This would be made worse by heat expansion. If the connector seems to bottom out on the top of the battery post before it firmly grips the sides you can put thin lead shims around the posts to tighten the helmet to post fit. Some replacement batteries do not have terminals of the proper size & taper to fit the helmets correctly.

Better yet is to replace the cables or at least the connectors with modern type clamps. Don't use the type of connectors that just clamp the cable end with a couple of bolts. For a small sum, an auto electric or battery shop can put on good connectors that are crimped on to the wire ends.

Don't forget to check & clean the heavy ground strap connections between the engine & the frame.

You can check the starter relay in the engine compartment by bypassing it. Jumper the two large terminals with a single wire from a battery jumper cable. If this part is bad, the engine will crank when you make the connection. Stay cool, & don't jump & let the jumper ends get loose to touch ground. Make & break this connection quickly to prevent unnecessary arcing.

A clue can often be found by turning on all the lights for a while & feeling the various connections for heat. There should be none unless it is a "bad" connection.

If none of this works, have an auto electric shop check the starter. Bad windings, bad brushes, worn bearings that let the starters armature drag on the field poles, are possibilities.

Start at the top of the list & work down, an item at a time. If you want true reliability I would suggest doing all of the above even if you find the problem before reaching the end of the list. The system is only as good as it's weakest link. There are quicker ways to isolate the problem by measuring voltage drops across the various parts of the circuit, but chances are that it all needs to be done as a part of general maintenance. Fixing a piece at a time as things fail can be very frustrating.
D

 

[Wana]

WOW, thanks for the quick responses. I will start down the list and see what I come up with. What a great forum!

 

[chuck1006]

I had that problem on my 1959 100-6 and it was the starter itself. Replaced it with a gear reduction one and have not had a problem since.
Good luck!

 

[Wana]

Follow up

OK, I took the old battery out to clean and inspect. The previous owner had left the receipt for the battery underneath it - purchased in 1998. So, I decided a new battery was a good idea and purchased an Optima (on the suggestion of another thread). I also decided to go ahead and bypass the cut-off switch as Dave and Andrew had suggested. I moved the ground strap to the terminal that goes to the battery. Installed the new battery and gave her a whirl. WOW! Fired right up, very strong turning by the starter (just like a "real" car). Idled for about 10 seconds, then died, no coughing and sputtering, just died quickly and wouldn't start again. The engine turned over great, but wouldn't start. Upon inspection I noticed the little black wire coming out of the center of the cut-off switch had broken off, apparently during my handiwork. The other end of that wire went to a screw on the back of the car where several other small wires went. I guessed that it was a ground? I pulled the broken end of the wire up away from the switch and just left it up in the air. Tried starting the car again and it fired right up. So, my question is; can I just tape this wire off or get rid of it, or does it play an important role in my now bypassed cut-off switch?

 

[Wana]

Re: Follow up

I failed to say that I did go for a drive, got it good and hot, then shut it off and it started right up again no problems. Thanks all for the help!

 

[Dave Russell]

Re: Follow up

That "wire" is supposed to ground the ignition points when the battery switch is in the disconnected position. If it gets grounded any other time it disables the ignition. Just insulate the end & secure it out of the way.

I know it's a lot of trouble, but I would go ahead with all the other connection checks - cleaning. It might save you a lot of various mystery problems in the future.
D

 

[Keoke]

Re: Follow up

WANA, If i understand you correctly the wire which you found broken off at the cut off switch should have been a Black and White wire which ends up at the Coil. The fact it was broken off would allow the engine to start.Perhaps by it just flopping around back there it could have accidently grounded it self and if the cut off switch is bad it would stop the engine and prevent it from starting.For now I would leave it diconnected. and see if the car continues to perform well.---Keoke

 

[Wana]

Re: Follow up

My sincere thanks again gentlemen.

 

[Keoke]

Re: Follow up

Wana, Our pleasure be assured---Keoke /ubbthreads/images/graemlins/yesnod.gif