Motor turns VERY slow

C

COOTER

Senior Member
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.
 
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.
 
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.
 
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
 
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.
 
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.
 
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.
 
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!
 
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.
 
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 said:
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.
Click to expand...

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.
 
COOTER said:
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.
Click to expand...

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! :-)
 
Big hammer said:
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! :-)
Click to expand...
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.
 
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