bad starter?

[mikepotts]

Starter diameter 4"
Amp draw Nom. 150-200A
Min. cranking voltage 9.6V
Engine rpm 180-250 RPM

Starter diameter 4-1/2"
Amp draw Nom. 150-180A
Min. cranking voltage 9.6V
Engine rpm 180-290 RPM

Do note that you maybe condeming a good starter that just has a bad pull in solenoid with burnt contacts, The way I test starters is with a clamp on current meter and testing the voltage to the actual starter motor, not the main battery connection to the solenoid, this elimates false diagnosise.

Have you made sure all the starter bolts are present and not loose causing poor ground from engine to starter?

i dont know why i didnt think of the amp probe, ive still got my Fieldpiece HVAC meter with amp clamp from the old days. i did notice the starter was firmly in place when i changed the battery/starter pos. cable.

 

[mikepotts]

UPDATE: the starter i mentioned from pepboys is THE INCORRECT STARTER! i waited a week for it to come in only to find it was WAY different. went to my local advance auto parts (i dont know why i didnt do this from the beginning), and they had the correct one in stock, their starter fixed the truck, WOW! this truck has never cranked like this! very fast cranking and immediate starts! thanks to all that helped and posted here.

 

[nj_m715]

Glad you got it solved. FYI, There are 2 or 3 very different looking starters that fit our motors. It could have been one of them.

 

[Danielle]

I was the same way when I replaced my starter at the rally haha. My truck had never started like this before! It is awesome haha

 

[BDCarrillo]

Can someone please post up what RPM their starter is actually turning the motor? May help other folks identify their issue

 

[mu2bdriver]

300RPM. Gear reduction, new aftermarket starter. Replaced an original like design which spun the engine at 200RPM.

 

[BDCarrillo]

300RPM. Gear reduction, new aftermarket starter. Replaced an original like design which spun the engine at 200RPM.

Thanks! I had a tired old Mitsubishi planetary gear reduction starter that was turning barely over 100 rpm. Turns out the commutator was heavy pitted and the brushes were worn unevenly.

 

[icanfixall]

The original direct drive starters were a very slow turning starter but they had some torque too. Problem is we need a fast spinning engine to create the needed heat for the combustion to take place. Faster the engine spins the hotter the compression is. Our diesels like all the rest are a compression combustion ignition. Compress the air and make it hot. The more lbs of compression and the faster you crank it the hotter the air is in the cylinders.