Slow Crank... Can't figure out way. Need fix ASAP!

[Mark Ashford]

392 w/345 heads in Scout II (my racer). Has always started fine. Last race I killed the radiator, I'm pretty sure I DID NOT over-heat it, but it started to crank slowly. I could get it started but something wasn't right. I thought it was the battery or an over-heated starter (right next to the headers). Finished that race day.

Fast forward to today (about a month), been working on some other things and finally ready to get it back moving (especially since I have race Sunday). Fresh battery - Slow crank.

Swap Starter - Slow crank.
Take jumper leads DIRECTLY to the starter - Slow crank.
Pull Plugs - Slow crank.
I can turn it over by hand, doesn't seem excessively hard.

Possibly and another bad starter?
Something else I should look at?
Oil looks good. I get a puff of air out of each spark plug hole, so I don't suspect broken rod or something. Haven't done a compression test though.


Thoughts???

[Jeff Jamison]

I would try another starter first if it turns over easy by hand.I had a travelall that had a 392 that did that after it sat for a couple of months,ended up pulling all the rods,and then the mains,everything seemed fine,put it back together and it was fine.
Does it crank slow then speed up and then slow,or just slow all the time.Try starting with something else also jumping it and see if it cranks faster
Jeff

[benmaples]

Make sure the cables & connections are capable of carrying the proper amperage to the starter. If you blew the rad, the coolant could have dumped enough to not allow the temp sensor to read an over heat condition. Why they put cylinder head temp sensors on later model motors. Maybe you could watch your ammeter [if you have one] while cranking & see how much the starter's pulling. I have an amp [AC/DC] clamp for my Fluke meter if ya wanna swing by & borrow it

[jeff campbell]

mark,get on that compression test,if you've done all the above,then see whats pumping in them cylinder's.jeff

[Super Scout]

I would try another starter, I went thru 3 autozone starters once on my 73. Each one was mess up I spent a long time trying to figure out what the hell was wrong. Damn cheap starter.

[Will Marsh]

Either toasted starter or toasted cables. Since the jumper cables didn't change it I'd do the starter first. I have a few to choose from, I bet you do too.

Not much else it could be, if it's turning over at all. With the spark plugs out a good starter will turn it nearly idle speed. (but you knew that).

HTH,

Will Marsh

[Mark Ashford]

I went through 2 of my "spare" starters. No difference. Sounds like its REALLY laboring to turn it over and drawing a ton of amps (should put the amp meter on it tomorrow.

And this is jumping DIRECTLY to the starter, on truck wiring involved.


Is kind of cranks slow, then hits a "hard spot" then cranks again. I even disconnected the tranny (auto) thinking it might be draging or broken, no difference.

Its entirely possible the extra starter I grabbed (I think I have like 6+ on a shelf) could be just as bad, changing thems kind of a PITA though, thank good for a severely cut and shaved truck.... and that who ever designed the headers made sure the starter can come out.

I think tomorrow morning I'm going to run over to my storage yard, test that yank the starter out of my old racer's chassis. If it cranks over that engine (304) good, then I'll try it in the 392 and see if that makes a difference. I'll probably order up a starter from the parts house as well. Just in case.

If a known good starter still has the same issues, then out comes the motor and in will go the old 304. I hope it still runs... or I may just have to skip the race. I don't want to as its a points series, but family and stress level comes first.


I did get it to run earlier this evening. Sounded normal (running), lifters were clattering like no ones business, then it ran out of gas (propane) and I was not able to get it to start again, the starters REALLY working. I hope I didn't kill something in the motor.... but I can't think of what it would have been to cause this issue.

[jeff campbell]

put a shield over the starter,even if it's metal,it'll help get some heat away.jeff

[Mark Ashford]

Originally Posted by jeff campbell

put a shield over the starter,even if it's metal,it'll help get some heat away.jeff

Agreed. Somewhere around here I have a factory shield... even set it aside to eventually put in on this truck. Now, naturally I can't find it.



Update, as was suspected all along, bad starter. Or more correctly a string of bad starters from my "spare" pile. Broke down and bought a new one this morning, installed it and it fires right off. Actually it still sounds a little funny, but this engine has always started a *little* funny.


Good thing too as my "spare" 304 still in the chassis of my old racer was NOT ready to go. Needed a couple freeze plug and it wouldn't turn over worth a darn as well (probably another crap starter). Pulled a couple more starters out of my parts pile and one wouldn't even turn over, another would eject but not spin and a third spun about as well as the one I took out. I think I just need to junk all but one or two to keep as cores. O-well, I need to clean up anyway....

[DavidWTravelallfan]

Put oversized cables on and get a DELCO brand starter NEW.. I have one on my Travelall with headers and starts fine.