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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: the_legend_1981 on September 13, 2012, 11:16:12 am

Title: truck turns over slow when hot
Post by: the_legend_1981 on September 13, 2012, 11:16:12 am
94 chevy 1500 runs great but cranks slow when its hot. Tbi 305...im going to check the wiring and stuff tomorrow but i'm looking for ideas if anyone has them. Thanks for any help
Title: Re: truck turns over slow when hot
Post by: gildardo01 on September 13, 2012, 01:28:52 pm
i think it has to do with the starter... when it gets hot for the exhaust itīs hard for it to turn the engine... sometimes it wonīt even crank as if you had a dead battery... you can put a heat shield blanket around the starter they run about 20 dollars at summit racing... this is what i think it is... lets see what over people have to say about it this issue....
Title: Re: truck turns over slow when hot
Post by: 454Man on September 13, 2012, 01:35:47 pm
 I bought that 20 buck starter blanket and it works good
Title: Re: truck turns over slow when hot
Post by: Fairlane514 on September 13, 2012, 01:45:41 pm
Check your timing, you may be too far advanced.
Title: Re: truck turns over slow when hot
Post by: bd on September 13, 2012, 01:46:06 pm
Begin by performing the basics: check ignition timing, load test the battery, measure starter current draw, and verify charging system operation.  Make sure there's no audible exhaust leak around the starter.  If the battery loads within spec, measure voltage drops across the positive battery cable to the starter and the ground cable, while cranking.  Make sure a starter heat shield is installed; the previously mentioned blankets work well.
Title: Re: truck turns over slow when hot
Post by: the_legend_1981 on September 13, 2012, 08:26:30 pm
Good info...it almost sounds like timing sometimes...like dieseling...but i dont notice it otherwise
Title: Re: truck turns over slow when hot
Post by: Irish_Alley on September 14, 2012, 11:22:28 am
starter is more than likely the problem, either is week and dying or its heat soak. if your batter test good then i would start looking for a new starter i dont see putting a band aid over something thats going bad
Title: Re: truck turns over slow when hot
Post by: 86c10 on September 17, 2012, 03:52:24 pm
My '86 did the same thing when I got it. It would start good cold but when it got hot I had to jump start it. After a lot of head scratching it turned out to be a bad negative battery cable and a bad ground strap at the bad of the block. I checked the battery, timing and starter before I found the problem. Good luck.
Title: Re: truck turns over slow when hot
Post by: zieg85 on September 17, 2012, 05:42:09 pm
Have the battery load tested, bet it is weak
Title: Re: truck turns over slow when hot
Post by: 1980c10 on September 18, 2012, 02:14:33 pm
I had the same problem this summer, ended up being a bad armature in the starter.
regardless, load test the battery(becuase its easy), clean, tighten and check all connections at the battery, starter, altenator and grounds.
if that doesn't work I like to use a jumper cable (or an 8 guage wire) and jump the battery (B-) to ground and try it, then (B+) to the alt, try it, the (B+) to the starter etc until you have tried it with each section of wiring bypassed.   
if this doesn't pinpoint your problem I would remove the starter and bring it in somewhere and have it tested, unless of course you are able.
As far as heat interferance from headers etc; if it has worked fine in the past with the set up you have now, it isn't going to be your problem now.
Title: Re: truck turns over slow when hot
Post by: roger97338 on September 19, 2012, 12:03:49 pm
I had a similar problem for a few months. I tested the starter, battery, alternator, and they were all good, but I still had the problem. It turned out to be the ground cable that runs from the battery to the block.
Title: Re: truck turns over slow when hot
Post by: travisr1988 on February 22, 2013, 08:39:25 pm
mine used to do that when i drove alot on hot days, after sitting for a few minutes it'd start right up again. my dad said it was just heat "soaking" into the starter.