Engine cranks very slowly when starting, battery not dead

[Guest Ansis42]

Hello all,

I have a 1980 Buick LeSabre with a 4.9L 301 V8. I am working out the kinks after replacing both head gaskets. I am experiencing a very strange issue lately.

I attempted to start it up one day. The engine cranked VERY slowly. But then out of nowhere, through some miracle, it started right up. I let it run for a while, and drove it around my neighborhood. I turned off the engine, then immediately tried starting it up again. Again, the engine cranked VERY slowly. This time, however, it never actually started.

I figured the battery was dead or dying. I thought this was odd because this was a brand-new battery. So, I bought myself a multi-meter, and tested out the battery. It had almost a full charge at about 12.5. So, I thought that was weird. I figured I'd test for a short. The multi-meter indicated there was no draw at all at -0.00.

So then, after proving that the battery was fine, I figured I'd try to start it up again. It cranked nearly perfectly (only a tiny-bit slow), and started right up. Let it run for a while, then turned off the engine. Again, I immediately tried starting it up again. Again, it cranked VERY slowly, and never actually started.

So......starter?

Any help would be greatly appreciated. Thank you.

[28 Chrysler]

Check the starter, solenoid, and all the connections.

Check the battery's voltage drop while you are cranking the engine to see if the starter is drawing to much current.

[cahartley]

On a car that age I expect the starter bushings have had it........brushes too probably.

[bhambulldog]

On a car that age I expect the starter bushings have had it........brushes too probably.

I agree.

That could also cause the starter to overheat. Further causing the starter motor to run slower. A slow starter will also damage the brushes,

The heat will also raise resistance in the wires, reducing the voltage reaching the starter.

A vicious cycle

[vintagerodshop]

Remember always start with the basics. if the battery is a known good part look at battery connections and cables first. Corrosion and loose connections have caused a lot of spinning the Parts Wheel of Fortune.

[misterc9]

Was the distributor removed or disturbed during this job? Timing could be advanced . This could cause slow cranking. You need to test voltage while cranking starter. Try jumpers from a running car. Was the battery ground strap disturbed where it bolts to the engine ? Might be a bad connection somewhere.

[Guest AlCapone]

My suggestion is to check the ground connection. Clean it or sand it shiny, I then on all my cars add. 00 welders ground cable. It worked for me and I had your problem several times. Wayne

Edited December 11, 2014 by AlCapone (see edit history)

[plt341]

my 1987 f-250 460cid cranked slow and would not start when hot.It had a broken connection on one of the field coils.Rebuilt starter replaced bad field coil problem solved.Never had a starting problem again.

[Hudsy Wudsy]

My suggestion is to check the ground connection. Clean it or sand it shiny, I then on all my cars add. 00 welders ground cable. It works for MPEG and I had your problem several times. Wayne

By all means, start with Wayne's diagnosis first. I, too, have found that ground cables can "look" like they have clean connections, but simply don't! Also, because the starter is turning you might think that the connections are sufficient, but substantial current can be lost there, nevertheless. I also have run into this more than once.