The Stovebolt Site Forums The Shop Area Engine Shop 235 Not turning over with start

I just changed out the fuel pump in my 46 COE. It has a full pressure 235 in it. It's been a few months since it ran but a few month ago it started right up.

After the fuel pump was installed the engine would not turn over with the starter. I did not check to see if it turned over prior to changing. The teeth are engaging it just appears it doesn't have enough juice to turn it over. I makes that "I'm trying but it's not going to work" sound.

1. I pulled the starter out and bench tested it, works fine.
2. Put it back in same problem, doesn't work.
3. Teeth are engaging.
4. Pulled all spark plugs, still won't turn over with the starter.
5. I pulled the inspection coverage off the bellhousing. I can turn the engine over with my hand, fairly easy. Verified teeth are engaging with the flywheel.
6. Pulled the starter off my 52 2ton. Put it in the COE. Same problem. The 52 ton ran a few weeks ago.
7. I bypassed the wiring and hooked the jump starter directly to the starter while on engine. won't turn over.
8. Turned the engine over by hand while my son verified the rockers were all moving. (I'm not sure why I did this, it just seemd like a good thing to do)
9. Pulled the fuel pump, problem is still there.

car is in neutral, battery is good, car is pos. ground. But most of the time I have been bypassing the wiring and hooking directly to the starter.

This seems like such a simple problem, I just can't figure it out. I'm thinking maybe when I installed the fuel pump something got into the hole and jammed it up. But what I can figure out is why can I turn it over by hand.

Help.

What is the starter doing? You say the teeth engage, so the starter drive is OK? Does the starter spin or do nothing? I'm thinking you should have a negitive ground as opposed to a positive ground? So how is the engine grounded? Most trucks have a braided cable from the frame to the engine.

The teeth are poping out and engaging with the flywheel teeth, the problem is the flywheel isn't turning.

It is positive ground. But it have been bypassing the battery with my jump starter and hooking up directly to the starter. I attempted with the battery and no jumper starter and it does the same thing. I'm not sure if the nef vrs pos ground matters with the starter. I have switched the cables from the jump starter and it made no difference.

What gauge cables are on your "jump starter".

What brand/model of "jump starter" do you have?

"Battery is good." Did you check the voltage across its posts

It sounds like a ground connection to me. Check all your connections and I'll bet you find the problem IF your battery is good. I'm not an auto electric expert but I've found the battery to be the source of most of the problems I've had.

Does your negative battery cable go to the frame or engine? You may find that you have a separate cable from the engine to the frame. Make sure both are clean.

Take a voltmeter, and measure the voltage drop between the battery post and the engine when you are trying to start it. If you have more than .3V or so, then you have a bad connection. Do the same with the positive terminal.

You'll probably need a helper to do this.

Just a random thought: If you can turn the engine by hand easily and the flywheel turns when doing so then the problem has to be in the starter. I know you said you tried a different starter with the same results. Perhaps it needs shims, It may be meshing so tight up against the flywheel that it binds the starter and won't allow it to turn.

EDIT: I notice that the starter out of your 52 should be a negative ground starter. Does hooking it up backwards make it turn a different direction? I don't know the answer to that question.

Starters run the same direction regardless of polarity unless they're the permanent-magnet type that have come into use in the past 20 years or so. It sounds like there's a connection problem, or the battery just isn't up to the task of heavy-load cranking. Do a full-load battery test, where half the cold cranking amp rating is applied for 15 seconds, then the terminal voltage is checked. 12 volt batteries should show at least 9.6 volts at the end of the load test, and 6 volt batteries should show at least 4.5 volts after loading.
Jerry

From reading his posts it would seem that he has eliminated the battery from the equation by using his charger pack direct to the starter. Correct me if I'm wrong.

push start it..

Jumper pack directly to the starter alone likely won't be enough. They're made to assist the battery.

I came across this problem in a 150 Chevy truck.

Turns out the battery cable went to the frame and another from the frame to engine because the battery was still under the floor.

Took the cable loose at the frame in both places and cleaned the cable and frame and the truck started.

Thanks for the replies. I think the majority of my problem was the assumption that the jump starter would supply enough juice to bypass the battery entirely, I don't think that is the case.

I made some new battery cables, hooked everything back up, didn't work. I then moved the ground from the back of the transmission to the engine block. The engine turned over without the spark plugs in. For whatever reason grounding to the transmission doesn't work. I cleaned the groung pad up and it still doesn't like it when I ground to the tranny.

I have also determined that my battery is shot. When I hit the starter the voltage drops from 6.2v range to 1.8v. I think the battery is done. I've ran it dead more than 20 times. I use it in an old 8n tractor that doesn't like to start in the winter.

Have you checked the concentration of the acid? When a battery is fully charged, the specific gravity of the acid is going to be 1.265 or so, possibly as much as 1.300. A discharged battery can have a gravity reading as low as 1.100 or less. By measuring the strength of the acid with a hydrometer, you can determine whether or not the battery is accepting a charge. "Sulfated" batteries have the ability to accept a surface charge, but they have little or no reserve capacity. One or two tries at starting will drain them badly. Sometimes a sulfated battery can be reclaimed by repeatedly slow charging it, then running it all the way down by connecting a slow, constant drain like a headlight bulb. Try a few drain/recharge cycles before giving up on this one.
Jerry

Unless you reverse
either the field or the armature a DC motor will not reverse. True for series (starter motors) shunt and compound.

You can reverse DC line without reversing motor.

EXCEPTION permanent magnet DC motors. In this case reversing the line reverses the armature and the motor will reverse.

Dan Bentler

Buy a new battery and use it to start the motor. Not your jumper.

If you are going to keep the truck and you are planing to stay 6v, buying a good, new battery is money well-spent (as cmayna suggests) AND buying correct gauge battery (2, or preferably 0, or 00) cables (both leads) are also a necessity (and thus is also money well spent).