[Bobs36ford]

Hi
My ride has a 350 Chevy engine. When engine is cold it starts right up. After engine warms up ....when starting it turns over real slow and sounds like battery problem. I know it is not a battery problem because no matter how cold it is it will start right away. Could this be a solenoid problem?

Bob

[T-bucket23]

Classic starter heat soak. You can try a shield but usually they don't work.
What brand starter is it. If it is one of those cheap chrome ones, throw it away and get a good starter.
A remote solenoid will not help if the starter is turning slowly

[EOD Guy]

My heat shield worked great.

[adantessr]

Originally Posted by Bobs36ford

Hi
My ride has a 350 Chevy engine. When engine is cold it starts right up. After engine warms up ....when starting it turns over real slow and sounds like battery problem. I know it is not a battery problem because no matter how cold it is it will start right away. Could this be a solenoid problem?

Bob

I had one of the small starters that did the same thing. Acted like a dead battery when it was hot. Replaced with a regular starter and eliminated the problem.

[gonzo08383]

starter is heat soaked. wrap it with heat wrap or install a cheap heat shield. i had this problem before. of course if the damage is already done the starter is on its way out no matter what.

[Bobs36ford]

Originally Posted by T-bucket23

Classic starter heat soak. You can try a shield but usually they don't work.
What brand starter is it. If it is one of those cheap chrome ones, throw it away and get a good starter.
A remote solenoid will not help if the starter is turning slowly

I do not know what brand...I'll check it out

Thanks

Bob

[Bobs36ford]

Originally Posted by gonzo08383

starter is heat soaked. wrap it with heat wrap or install a cheap heat shield. i had this problem before. of course if the damage is already done the starter is on its way out no matter what.

Thanks for the info

Bob

[vicrod]

You could check the timing. Too much advance can cause resistance to piston travel when the spark fires to early on the upstroke.
Also check the mechanical and vacuum advance for proper operation.
An easy test is disconnect the ignition wire and try cranking the engine to rule out the timing issue.

vicrod

[Bobs36ford]

Originally Posted by vicrod

You could check the timing. Too much advance can cause resistance to piston travel when the spark fires to early on the upstroke.
Also check the mechanical and vacuum advance for proper operation.
An easy test is disconnect the ignition wire and try cranking the engine to rule out the timing issue.

vicrod

Thanks, I will check out the timing issue first.

Bob

[Bobs36ford]

Originally Posted by vicrod

You could check the timing. Too much advance can cause resistance to piston travel when the spark fires to early on the upstroke.
Also check the mechanical and vacuum advance for proper operation.
An easy test is disconnect the ignition wire and try cranking the engine to rule out the timing issue.

vicrod

If the timing is off ,would the engine turn over slowly all the time...not just when its hot?

Bob

[starnest]

I've heard of too much advance causing an engine to turn over slow, but I've never actually seen it happen. Like Bob, I think if timing is a factor it would be the same hot or cold.

I have seen slow starting with hot engines, usually the problem occurs with headers too close to the starter.

In practice, the resistance of electrical components increase with temperature. This is essentially true for every electrical component from switches to wiring.

According to Ohm's law (I=E/R, current equals voltage divided by resistance) the current through the starter motor decreases as the resistance (temperature) increases.
The starter motor force is proportional to the current, the rotation rate (speed) is proportional to the force generated by the current. Thus, when the starter gets hot it turns slower.

In most cases the difference is not noticable, but sometimes (especially if the windings in the motor are partially shorted/open or the brushes are glazed/broken) the difference can cause the motor to spin slowly or not at all. In these cases the starter motor will eventually fail.

First, verify that your starter is good, remember it will work good on the bench with no load attached. You need to disassemble and check the brushes, armature windings, etc. Look for cracking or burn marks in the coating of the windings.

If the starter checks out and you have a heat source (headers) adjacent to the starter motor, then look at a heat shield for the starter and/or heat wrap for the headers.

[Bobs36ford]

Originally Posted by starnest

I've heard of too much advance causing an engine to turn over slow, but I've never actually seen it happen. Like Bob, I think if timing is a factor it would be the same hot or cold.

I have seen slow starting with hot engines, usually the problem occurs with headers too close to the starter.

In practice, the resistance of electrical components increase with temperature. This is essentially true for every electrical component from switches to wiring.

According to Ohm's law (I=E/R, current equals voltage divided by resistance) the current through the starter motor decreases as the resistance (temperature) increases.
The starter motor force is proportional to the current, the rotation rate (speed) is proportional to the force generated by the current. Thus, when the starter gets hot it turns slower.

In most cases the difference is not noticable, but sometimes (especially if the windings in the motor are partially shorted/open or the brushes are glazed/broken) the difference can cause the motor to spin slowly or not at all. In these cases the starter motor will eventually fail.

First, verify that your starter is good, remember it will work good on the bench with no load attached. You need to disassemble and check the brushes, armature windings, etc. Look for cracking or burn marks in the coating of the windings.

If the starter checks out and you have a heat source (headers) adjacent to the starter motor, then look at a heat shield for the starter and/or heat wrap for the headers.

The header is about 1 inch from starter, I'm trying heat shield
first. Thanks a million......Bob

[T-bucket23]

Originally Posted by Bobs36ford

If the timing is off ,would the engine turn over slowly all the time...not just when its hot?

Bob

It will be worse when it is hot

[vicrod]

A hot engine (combustion chamber) will fire the FA mixture more rapidly than when cold.
In extreme cases, when residual fuel is available, an engine will "run-on" after the ignition is turned off.
Not sure it's your problem but it happens.

vicrod