Slow crank worse each time...

[Matt_INW]

Goodness, why didn't I think of that. I've been staring at it off and on thinking about it. Guess the original owner put in backwards when they made the butchered positive cable. Will try that when I get back home!

Thanks guys, If this works I may just throw on the $22 started solenoid on the fender to see if it finishes fixing the problem. But I don't know if I want to throw $22 away if that's not the problem and it turns out the starter is in fact dying.

 

[BDCarrillo]

DBelectric has some pretty good, new starters for around $80 or $90

 

[biggun]

hey Buddy did you get this figured out?

 

[Matt_INW]

That did the trick, plenty of cable flipping the battery around, lol. I got home, worked on it, then took a road trip (25miles one way) for a tasty huge chocolate fudge shake to make sure the batteries were charged decently (if they weren't already).

So it turns over a little decently cold, not normal speed though, and starts. If you turn it off, then try starting after a few seconds, it turns over decently (though not normal speed) and starts. But if you let it sit several minutes after running, it is pretty slow to start. So I'm guessing that after the engine is off and heat spreading around to an already weak started/solenoid, the thing complains even more? I'm thinking it's not the fender solenoid, and not the negative cables. Thoughts? Worth throwing a starter on it, or not and spend ~$80 or more at a shop to diagnose (yay)? I'm leaning towards the shop, but sorta considering throwing a started at it (not cheap esp after the $125 positive cable).

 

[79jasper]

Starters can do that.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[biggun]

did you try putting a battery charger on it (on Start selection) and seeing if that makes it crank faster? i know my 86 will crank faster with the battery charger, until i replaced the batteries. getting a powermaster starter for it, not taking chances during the winter.

 

[towcat]

things I've learned from working on electronically dependant trucks.......
1) a .5 voltage drop between a battery stud and connector will cause a slow/no crank.
how to measure this. firstly, key off engine off.
open hood and with a digital DVM, set the readout to hundredths. ie ex. 12.50 volt readout.
place probes at top of battery studs and take baseline reading. let's use example of 12.60volts as your baseline.
then place probes on terminal ends and take a reading. you should see the same if terminals are clean and tight.
IF you see a readout of 12.59 to 12.1, you should disassemble terminals and clean them.
IF you see a readout of 12.0 or less, start checking cable conditions.

chances are you are chasing a vicious circle of problems.
you need a minimum of 300 engine rpm for cranking speed. anything less requires more amps to start your truck and as the amps go up, so does heat in the components and the slower things get.,,,,,,,,,,,,,,

good luck. let us know what you find.

 

[Matt_INW]

I did try hooking up my suburban (running) to see if it affected the crank speed, it had zero effect. At that point I made my final decision to buy a starter. First I replaced the fender solenoid, just in case it was the issue, it wasn't. Then I replaced the starter, BINGO! The thing sounds like it's high on something. Seriously, I thought it turned over fast before the starter began failing a couple weeks ago. Before it would start after less than a second. Now, I swear it starts before I turn it over. And if I don't warm the glow plugs (which I deliberately didn't do to be sure it turned over fast), the thing sounds like it's going to take off.

Anyways, new positive cable since it looked like crap and had a little resistance, new starter solenoid on fender, and finally new starter (not reman even).

Does anyone need a mostly dead starter to rebuild at a later time? Core is worth I think $100, but I'll take a small fraction of that plus shipping.

 

[icanfixall]

Well you finally found the real issues but replacing suspect cables is insurance the new starter will last. Just remember a slow cranking starter is pulling high amps and creates lots of heat. a slow cranking engine wont start either. Diesels are compression ignition engines and that means they crank fast making plenty of high compression air that is super heated so it ignites the diesel. Try to start the idi by hand cranking it...