Slow cranking when hot

[kanz24]

Guys I have a 97 Tahoe that for some reason always has a slow cranking issue when hot. So far I have replaced the battery, Starter and Alternator with no luck solving this issue. There is nothing worse that having to stop for gas after an hour of driving and the truck barely cranks over. Any ideas?

 

[ISU-152]

Sounds like a wiring issue. Check all connections to those 3 parts, sand all connections

 

[kanz24]

If I was a wiring issue wouldn't it happen all the time? This only happens when the truck is driven for awhile.

 

[YukonandtheHOE]

How many miles are on the engine? Its possible that if its a recent rebuild tolerances are to close max and warm parts expand.

 

[kanz24]

The engine has 140,000 on it.

 

[YukonandtheHOE]

Definitely not internal clearances..
Do you have headers?

Is the heat shield off the starter?

Starter Solenoids can get heat soaked and cause higher amperage draw = slow cranking.

 

[2011SSVHOE]

Check your ground connection. I had a firebird that did the same thing turned out to be a corroded head bolt in the block . The ground cable attached to the head bolt . Started up good when cold too much resistance when hot

 

[kanz24]

No headers. The truck is bone stock.
I will look at the grounds. Thanks guys

 

[99Vortec]

Almost sounds like the system is trying to throw out the spark a bit too early? Similar to too much advance on earlier models? (I.e. trying to throw out spark while compression stroke is still rising?) Idk, gl.

(Or you are overheating?)

 

[kanz24]

Sorry for the Late update guys. Well I found the culprit, It was the battery ground to engine. seems the wire was loose and once tightened their was no more hot cranking issues. Thanks again.