Got a strange problem with my starter

[nelstomlinson]

When the engine is room temperature the starter will crank the engine quickly for a couple rotations, then it slows way down, have to crank 15++ seconds to get it to start. When the engine is warm, it starts before the starter slows down.

The cheapie digital voltage gauge I have stuck in the cigarette lighter tells me the voltage is almost 12V while it's cranking fast, but drops to ~9V when it slows.

My first thought is the ancient starter has some kind of problem that only bites after a few revolutions. Any ideas what might be going on?

Should have added, it's the '91 plow truck.

 

[Nero]

Dropping to 9v when cranking isn't abnormal. I would get your batteries load tested. 12.6v does not mean a battery is maintaining full capacity. Also wouldn't hurt to make sure the major grounds are clean.

 

[nelstomlinson]

Batteries are a bit over a year old, NAPA's best.

The starter on that truck is the longest I've ever seen on one of these old rigs. I'm guessing it's pretty old. I guess it could be battery cables, too, or could be both.

 

[nelstomlinson]

I took the starter out to change the block heater. It was so long I barely had room to get it out. Now I'm thinking I should have put in a newer starter while I was in there.

Oh, well, it'll get its turn in the shop again next weekend, and I'll definitely check the grounds.

I guess I can cut back the insulation around the battery cables for an inch or so, and if they look good I can cover them again with heat shrink.

 

[IDIBRONCO]

I took the starter out to change the block heater. It was so long I barely had room to get it out.

That's the long style Mitsubishi starter.

My first thought is the ancient starter has some kind of problem that only bites after a few revolutions. Any ideas what might be going on?

This is my first thought as well. The starter works "better" when the engine is warm because a cold engine is harder to turn over so the starter has to work work more for a longer period of time. I would think about replacing the starter soon. After you check your cables though. That's never a bad idea.

 

[Old Goat]

There could be cracks in the full length of the cable insulation.
Moisture/Salt can get into the copper and you have corrosion you do not see.
I noticed one day both of my ground cables had cracks on both of them the full
length.
Measure the length of both and went to NAPA and had 2 new cables made with
Copper ring terminals crimped on. Also replaced the Positive cables as well.


Goat

 

[franklin2]

When you take it out, look at the face of the starter where it mounts, and also the surface on the adapter/bellhousing where the starter mounts. I worked on a old plow truck that always cranked slow, even with a new starter, batteries and wires. Found out eventually that the surface where the starter mounted was all corroded and not passing current through it to the block properly.

A wire brush on a drill and a little sanding, and all was well after that. That was the same truck where I had to ground the alternator case to get it to charge. It was so corroded it was not getting a good ground through the mounting brackets. I tried to loosen the alternator and the brackets to clean them up, but no go, they were going to break off. So the added ground wire fixed that part too.

When you are plowing snow, you are out in the worst conditions, when the salt on the road is thick. It's rough on everything.

 

[nelstomlinson]

We don't do salt up here much, but I'll definitely try cleaning it down to bare metal, no downside to that. Thanks.

 

[noddaz]

Are you still running the original direct drive starter? If so, there is a place to oil the nose of the starter. But the starter has to be off the truck to do it. Rockauto has a picture here. You can barely see the bump that is the oil port on the top of the nose of the starter.

You must be registered for see images attach

I finally realized the oil port was there when I changed my direct drive starter for the last time. I installed a gear reduction starter that I found a link for on the internet. The gear reduction starter has no problem spinning the engine fast enough to start it. You do have to change the solenoid activation wire connector, I found that to be no big deal.

 

[noddaz]

Are you still running the original direct drive starter? If so, there is a place to oil the nose of the starter. But the starter has to be off the truck to do it. Rockauto has a picture here. You can barely see the bump that is the oil port on the top of the nose of the starter.

You must be registered for see images attach

I finally realized the oil port was there when I changed my direct drive starter for the last time. I installed a gear reduction starter that I found a link for on the internet. The gear reduction starter has no problem spinning the engine fast enough to start it. You do have to change the solenoid activation wire connector, I found that to be no big deal.

 

[mblaney]

If you are replacing the starter consider getting the upgrade Powermaster 9050. This is a huge upgrade, especially over the crappy rebuilds you get with OEM style.

 

[Clb]

Fwiw

1 Laod test those new batteries irregardless of what napa says.
1 dead cell and viola....

2 Clean and nolox the connections both ground and hot.

3 resistance test the battery cables off the rig.

4 check starter relay.

Good luck
GeeLectricity sux sometimes

 

[mexicanjoe]

Some times there is green corrosion built up under the battery cable insulation. Peel it back about 1 foot from the batter. My cables and connectors looked good but the starter was too slow. Replaced the battery cables with welding cables and no prob.

 

[Clb]

Fine strand conductor
F.T.W

 

[Clb]

Just thought of this product...

Deoxit
Unlike contact cleaner, this helps to bust up corrosion. https://www.google.com/url?sa=t&sou...CB0QAQ&sqi=2&usg=AOvVaw3GkCqVMAsVnd4ef7ZVDGQV