Cold Start vs. Hot Start Issue

[JSeegs]

1993 GMC 1500 w/4.3 V6
Remanufactured, low mileage, engine and starter.
Battery good, alternator new.

When I go to start the truck and it is cold it fires right up and the starter sounds normal.

Often (but not always) When I go to start the truck when it has been running and is at temperature the starter sounds like it is is struggling. Almost like the battery is just about dead. It always kicks over and runs but doesn't sound right to me.

I'd swear it did the same thing with the old starter and engine as well?

Ideas????

Thanks

[Kim57]

Originally Posted by JSeegs

1993 GMC 1500 w/4.3 V6
Remanufactured, low mileage, engine and starter.
Battery good, alternator new.

When I go to start the truck and it is cold it fires right up and the starter sounds normal.

Often (but not always) When I go to start the truck when it has been running and is at temperature the starter sounds like it is is struggling. Almost like the battery is just about dead. It always kicks over and runs but doesn't sound right to me.

I'd swear it did the same thing with the old starter and engine as well?

Ideas????

Thanks

My 94 with the 5.7 is doing the same thing now with 148,000 miles.
I'm thinking my starter is going bad as it's the original.
Kim

[Shyguy]

Sounds like a heat soak problem. Are you running headers?

You could go with a small high torque starter. A 95 has the small starter.

I put one on my '74 454 and its real good.

[Kim57]

I don't have headers on mine so I think it's just old age getting to it.
Will a 95 starter just bolt in my 94?
Kim

[speedygonzales]

Don't buy anything until you tell us more and possibly do some testing.

How long has the replacement engine and starter been in? Was there ever a time when the new stuff was NOT doing this symptom? Can you tell us about the battery age etc? What makes you say it's good? Anything less then 11 volts and you have to stop there.

Could you have someone crank it over while you measure the voltage across the battery (while its cranking) in both dead cold and when it's hot and exhibiting the problem? I'm interested to know what the battery voltage is in both cases.

Next thing to try is using one jumper cable, go from the negative post of the battery to the outside of the starter and try it when it has the problem. See if it makes any difference.

One other thing I would suggest you do is when it's hot and doing the struggle problem, try jumping voltage with a jumper cable directly from the battery to the starter. You could connect the jumper to the starter and leave the other end disconnected while you run the engine to get it hot. Shut it off and turn the key to see if you get the same symptom then take the jumper to the battery post to crank it over to see if there is any difference.

These checks will eliminate a questionable battery and wiring. At that point, it would have to be the starter. You could then take it to be tested but be sure they test it AFTER having heated it up with something like a hair dryer. My guess would be the heat soak issue that others mentioned and that causes the starter to pull a lot more current once it's hot.

For a replacement starter, the only 2 things you need to confirm is the number of teeth on the flywheel and if it's straight or staggered mount. Usually the mount will indicate the number of teeth on the flywheel.

I highly recommend NOT getting the starter with a nose cone on it. One, you can't shim them accurately the first time to make it quiet if it needs shims like a denso style starter (non nose cone type). Second, sometimes a back fire can destroy the nose cone on the starter. If you have one that does not have a nose cone, you can't hurt what is NOT there.

The denso style starter is easy to shim once with a paper clip and it's done right.

[Blue97]

I've had this problem for years now, cold starts fine - op temp.....not so fine. But only during the summer. I did install a new battery but it didn't fix the problem... I figure I will wait until it gives up the ghost....

[franken]

Bad connections or bad cables if the battery is good and charged to 12.6V.