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-   -   Motor turns VERY slow (https://www.fordbarn.com/forum/showthread.php?t=220424)

COOTER 05-08-2017 12:13 PM

Motor turns VERY slow
 

I installed a new crank and cam gear, buttoned it all back up, set the timing and now the engine turns very slow. I'm talking really, really slow. Turns by hand pretty easily. Anything other than a low battery that would cause this. It was late in the evening so didn't get a chance to check voltage yet. Just wanna have a game plan before I get out to work on it again.

J Franklin 05-08-2017 12:19 PM

Re: Motor turns VERY slow
 

Charge the battery, clean the cable grounds and connections so there is little resistance and check the cables gauge for correct size. If it still doesn't turn well you should inspect the starter motor itself.

Beauford 05-08-2017 12:25 PM

Re: Motor turns VERY slow
 

Its the ground...mine did that.

SeaSlugs 05-08-2017 12:57 PM

Re: Motor turns VERY slow
 

yea poor ground or cable connections or weak battery. If questionable ground use a jumper cable from the frame rail to a head stud as a temporary measure - if it cranks fast you got paint buildup somewhere or rust most likely.

WHN 05-08-2017 01:40 PM

Re: Motor turns VERY slow
 

I would check all connections. Sounds like weak battery or bad connection.

Terry, NJ 05-08-2017 03:35 PM

Re: Motor turns VERY slow
 

Mine really weren't too slow cranking, but I was reading, maybe a year ago, about auxiliarily ground cables. I know that modern car occasionally will use them an I had a piece of heavy cable off an old Piper, So I made one up. Even a 12V would've worked. The Piper Tri pacer was either 12 or 24V (2 0 I think). I bolted it through the flange of the frame and ran it over to the bell housing, in one car, to the starter bolt. Wow What a difference a stupid extra ground cable can make! It spins a lot faster and the battery charge lasts longer. Cheap, efficient,
Terry

30 Tudor 05-08-2017 04:16 PM

Re: Motor turns VERY slow
 

Realistically, the engine needs to be grounded , the frame, the body,everything.

Granted the A drive train is not as insulated from ground as modern cars, but it matters.

I have seen pinion bearings, u-joints and transmissions destroyed by the current flow of having the ground flowing through them, as in welding,,,when ground straps were left off.
Every thing worked, but caused damage in the process.

Rock solid grounding between all the components just eliminates so many potential problems, and gives no opportunity for current to flow where it shouldn't and focuses where it should..
When I assemble my baby, it will be grounded,,and how.

jmeckel 05-08-2017 06:01 PM

Re: Motor turns VERY slow
 

A #2 copper wire attached to the bottom starter bolt (clean the paint off from the starter under the bolt so you get good contact) to the same location that the battery cable connects to the frame is a good idea. The engine pans were part of the original design to provide the ground path.

Jacksonlll 05-08-2017 06:22 PM

Re: Motor turns VERY slow
 

After you are sure your batt is fully charged and it still turns slow, quickly feel around for something hot, or warm. That will tell you where the high resistance is. Probably a batt connection.

jax55 05-08-2017 06:25 PM

Re: Motor turns VERY slow
 

I found the same problem. Added an additional ground to from the trans to the battery ground, cleaned everything and it cranks 90% better.
I would say 100%, but cranked OK before..but a clean extra ground helped a bunch!

COOTER 05-08-2017 09:41 PM

Re: Motor turns VERY slow
 

Didn't have any issues prior to the timing gear disintegration. Find it odd that at the same time a grounding issue sprung up...but anything's possible.

cpf240 05-08-2017 09:47 PM

Re: Motor turns VERY slow
 

Test the theory... take a jumper cable and connect one end to whichever terminal you are using for ground in your vehicle, and connect the other end to something solid on the engine, maybe a head bolt.

30 Tudor 05-08-2017 10:06 PM

Re: Motor turns VERY slow
 

Quote:

Originally Posted by 30 Tudor (Post 1469768)
Realistically, the engine needs to be grounded , the frame, the body,everything.

Granted the A drive train is not as insulated from ground as modern cars, but it matters.

I have seen pinion bearings, u-joints and transmissions destroyed by the current flow of having the ground flowing through them, as in welding,,,when ground straps were left off.
Every thing worked, but caused damage in the process.

Rock solid grounding between all the components just eliminates so many potential problems, and gives no opportunity for current to flow where it shouldn't and focuses where it should..
When I assemble my baby, it will be grounded,,and how.

The point I was trying to make and wasn't very clear, is that the frame and the drive train should be grounded together, and some times they are not.
If the only ground between a modern body and engine is the accelerator cable, they can go up in smoke.

Big hammer 05-10-2017 08:57 AM

Re: Motor turns VERY slow
 

Quote:

Originally Posted by COOTER (Post 1469937)
Didn't have any issues prior to the timing gear disintegration. Find it odd that at the same time a grounding issue sprung up...but anything's possible.

So you changed your timing gear! The front engine mount needed to come off, You loosened the rear mounts, put a jack under the engine, maybe loosened or removed the engine splash pans? These are all paths for grounds! :-)

SeaSlugs 05-10-2017 09:27 AM

Re: Motor turns VERY slow
 

Quote:

Originally Posted by Big hammer (Post 1470489)
So you changed your timing gear! The front engine mount needed to come off, You loosened the rear mounts, put a jack under the engine, maybe loosened or removed the engine splash pans? These are all paths for grounds! :-)

yup - i hate split washers or star washers being used as "gounds". For as easy as it is to add a ground cable and even easier to disquise it it should be added to every car...

Even your not so modern cars - if its more than 10 years old, remove the grounds (theres really hundreds of them but get the main ones - cable to frame, frame to engine/trans, headlights to core support, fuel pump to frame rail, and taillights to frame rails.), clean with a wire brush in a drill and re attach. I bet you will notice easier starting, faster cranking, smoother idle, brighter lights all around. GM headlights of the 80's - 2000's are known to have awful grounds due to only using star washers to bite thru the paint (supposedly) and carry the headlight load...same goes for fuel pump (maybe thats why they burn up so often - excess heat from the motor) and wonky brakelights. Chevy venture vans - when the brake light is on the reverse light and turn-signal spaz out with the brake light and those typical white 2500-3500 work vans it seems 6/10 have extremely dim brake lights.

COOTER 05-10-2017 09:41 AM

Re: Motor turns VERY slow
 

Battery was toast. Cranks strong now. You guys and your grounding worries. :-)

Big hammer 05-10-2017 12:00 PM

Re: Motor turns VERY slow
 

Thanks for the update! Happy motoring:-)


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