Sometimes the '70 turns over kinda sluggish after it sits following a drive. Its not a dead/waek battery issue because it will turn over very quickly and start first try if it sits for 2 weeks.

I'll drive around for awhile then park it for 10 or 15 mintues. When I try to start it again it doesnt spin over as fast. It acts like the battery is weak but I know its not the battery. When it starts it doesnt settle into a good idle, I have to give to give some gas to 'clear it out'. It almost feels like it got flooded while it sat.

Any thoughts or comments?

Stock-ish 350 4sp. w/ a no choke quadrajet.

Thanks,
Jim

 

Flooding won't cause the engine to turn slower or more sluggish, but if the wiring connections at the starter are getting hot and the connection gets bad it might affect things. Also, if the starter is getting hot and having trouble turning the engine then it may be time to look into replacing it.

 

I'm sure its 2 seperate issues. All of the wiring is new with good contacts so I can rule that out. I may try a starter heat blanket.

As far as the 'flooding' symptoms, all I could think of is the wrong heat range spark plugs.

JIm

 

Just for grins, check the resistance of the cable from the battery to the frame (ground) and the cable from the frame to the block. And then the positive cable from the battery to the starter. They can corrode internally and you can't see it. The cables can also corrode under the terminals at the frame. Any of those will cause hard/slow/sluggish starter problems..

 

I think I have a similar problem developing. I have owned my '71 for 25 yrs. I am seeing the same symptoms. I have a 1971 GM service manual. It explains the charging circuit [sect 6Y-16]. One [ALT term -1] side feeds the field coils of the alt. The other input [ALT term-2] is the voltage regulator function. Read the resistance [battery disconnected remove the +/ - ] between term/pin2 on the alt to ground. I read 14.7k ohms. that might be low. The manual states a "high resistance" and 14.7 is not high. I think that capacitor C1 is shorted. That will disable the field current to the alt. You/I are running on bat current. You will go a whole lot less at night. [so will the electiric only cars]. I think I'm going for an alternator but I'm still playing with this one. I have posted this to hear if anyone else has seen this [Battery weak/dead after drive] Term 1&2 are the plug in on the:o alt and are stamped 1/2 on the alt backing.

 

Both battery cable and the block to frame ground are new!!

My battery charges fine....would the alternator issue still hold true?

 

Re-check the ground connection. Even if you have to scrap the paint or attaching location. The engine may be seeking a ground. It will try to find one and it actually may be using the speedometer or the emergency brake cables. I know it sounds remote, but a good place for such conditions to happen is with slow cranking power and when everything works and is in good condition but acts as weak .

 

When my '69 was new, I used to have the same problem. I first noticed it when I-5 opened up in Central Calif. For the first time you could drive through a full tank of gas at speed. After a fillup on a hot day, the starter was sluggish, as if the battery was almost dead.

I fixed it by taking the starter apart and cleaning up the armature or commutator. I didn't have a lathe to turn it, but I did use a strip of fairly fine sandpaper and gave it a new look. Then I under cut the commutator. This is done with a hacksaw blade between the armature segments.

Here's a quote from the '69 Chev. Chassis Overhaul Manual: "Undercut insulation between commutator bars 1/32". This undercut must be the full width of insulation and flat at the bottom; a triangular groove will not be satisfactory. After undercutting, the slots should be cleaned out carefully to remove any dirt and copper dust."

That really fixed my sluggish starter problem. You might want to try it if all the tips mentioned in the previous posts don't cure it.

I just learned you can buy rebuild kits for our starters so you can retain the original body, important if you want to keep your Corvette original. I would definitely stay away from those life-time guarantee rebuilt starters, alternators, etc., that the national parts chains carry. You get what you pay for!

Cheers,
Pete