Need help diagnosing a problem

[majortom75]

I have had a problem lately with starting my '76. It normally happens when I've been driving it (i.e. the engine is still fairly warm). What happens is I will get in and turn the key to start the engine. Sometimes it doesn't catch in the first few seconds so I stop, wait a few seconds and try again (so as not to damage the starter). When I go to turn the key again nothing happens, as if I had a dead battery, except that the battery works fine. It is less than a year old (the battery) and everything still powers up ok. If I wait 10 minutes or so and try again the car usually starts right up.
Any thoughts as to what the problem might be would be most appreciated.
:confused

 

[GerryLP]

I have had a problem lately with starting my '76. It normally happens when I've been driving it (i.e. the engine is still fairly warm). What happens is I will get in and turn the key to start the engine. Sometimes it doesn't catch in the first few seconds so I stop, wait a few seconds and try again (so as not to damage the starter). When I go to turn the key again nothing happens, as if I had a dead battery, except that the battery works fine. It is less than a year old (the battery) and everything still powers up ok. If I wait 10 minutes or so and try again the car usually starts right up.
Any thoughts as to what the problem might be would be most appreciated.
:confused

Major,

When you say "it doesn't catch" I suspect that you mean that the starter is turning, but the engine won't lite-up? And when you say "as if I had a dead battery" I suspect you mean that it sounds as if it would when the starter turns the engine very slowly. I also suspect that when the car engine is cool (as it would be when sitting in the garage overnight) the starter turns and cranks the engine fine.

It seems as if the starter armature is grinding or touching against the coil field. The trick, however, is that this behavior could also be caused by a loose wire or bad connection. Therefore, check the connections good for corrosion or looseness. The armature bearings (which can be anywhere between just a pivot point and hole to an encased ball bearing assembly) sometimes go bad and create drag. This in turn causes the armature to wobble inside the starter casing. The wobble brings the armature close to the field and rub. If the starter is engaging, then the solenoid seems to be working fine. If there is sproket clearance problems, then this should cause the starter to make unusual noises.

One more thing, wear some eye protection and try starting your engine at the starter under the same conditions you discribed. If the car starts right-up, then you may have an ignition switch problem (if, again, the connections at the starter have been checked and no problems are found).

Dropping the starter is not too bad unless your engine has headers. Autozone and others will test the starter for you if you bring it in to the store.
Good luck!

 

[69_Dream]

The last part of your problem could be caused by excessive heat to the starter. The engine produced too much heat for the starter, and if you let it cool down for 10 minutes or so it starts right up. I'd check that your heat shield.

The first part about it not catching doesn't seem to fit with the above diagnosis... hopefully someone will sign on with an answer.

Sly

 

[majortom75]

I was also thinking maybe a loose connection at the starter, but given that it only seems to happen in this one certain scenario instead of randomly I'm thinking maybe an ignition switch problem. I'll check it out (hopefully tomorrow morning) and post a reply. Thanks.

 

[photovette]

My '77 does exactly the same thing--I'm sure it's a heat problem. I have a new starter and charging system. What heat shield?

 

[69_Dream]

Don't know much about the 77, not sure if it came with one that year. I'm almost certain they made up until at least 74. In case, you can probably retrofit to your application.

They also sell heat insulating wrap that wraps around the starter. It just slips right on.

Sly

 

[majortom75]

I checked the connections to the starter and they are ok. Also the heat shield (assuming you mean the metal plate between the starter and engine, is intact. I'm not convinced that it is a switch since it only seems to do it in this single instance (running starter the second time). Could it possibly be a starter motor problem?

 

[majortom75]

Photovette,

I replaced cap, rotor, ignition module (under the rotor) and starter. I'm not positive which part fixed the problem, but if your cap and rotor look ok, you may want to try swapping out the ignition module. This is what the guy at the auto parts store recommended when I explained it to him. Hope this helps.

Tom

 

[curtis]

my .02.....I think you have a burned disc in the starter solenoid. just change the $12 solenoid. when that high current starting load goes thru the disc contact it creates a lot of heat. If it is burned or pitted real bad, it won't work again till it cools off. my old 67 Chevelle used to burn those up all the time.

 

[pasvorto1]

When my '78 had "appears dead" problems, I took a wire brush and cleaned the battery connections. Haven't had the problem since.

 

[photovette]

I got rid of my dual electric fans and put the original fan, shroud, and a new HD fan clutch back in. I also added an aux fan from an '81. This solved the problem nicely. Starts instantly at all times now.

 

[wishuwerehere82]

I think Curtis is right. Solonoid or bendix gear not resetting.

 

[chrism]

I had the same problem and second the advice on the battery connections. The side post battery connections corrode quite easily and add resistance to the exceptionaly long and resistive battery cables. I'll bet if you wire brush the connections at the battery that the problem goes away. Afetr driving the car, starter windings offer more resistance when hot. All combined, the resistnce results in a large voltage drop that restricts the current required to properly operate the starer motor.

 

[RodsnRides]

I had the same problem and second the advice on the battery connections. The side post battery connections corrode quite easily and add resistance to the exceptionaly long and resistive battery cables. I'll bet if you wire brush the connections at the battery that the problem goes away. Afetr driving the car, starter windings offer more resistance when hot. All combined, the resistnce results in a large voltage drop that restricts the current required to properly operate the starer motor.

I agree with all of the above, but don't rule out the solenoid or the possibility of a "dead spot" on the armature. If it doesnt work, try to turn the engine by hand a couple of inches on the harmonic balancer, and try again. Seems weird, I know, but it has worked for me. And those side terminal battery connections are finicky, too-keep 'em clean, use a little screwdriver to polish the cable end that meets the battery terminal. Heat shields are available cheap through Summit Racing. I also heat wrap my wires going to the starter. Good luck.

Rick