[Jimmie Jazz]

My 1989 z24i HB is very difficult to crank over after it is warmed up. It is fine the first start of the day or whenever it gets a chance to cool down for an hour or so, but if I am out running errands, 15 minutes between stops and starts it won't even spin all the way around. It is like there is too much compression for the starter to overcome. If I keep at it eventually (after about three or four attempts) it will spin and start normally. It had been doing this for about a year, and so I recently replaced the timing set. That fixed a bunch of other problems (chain rattle, etc.) but this one remains. Oil pump timing is dead on, and the crank and cam sprocket marks are as close to aligned at TDC as possible.. ignition timing is 10 degrees BTDC, etc.

I'm kinda stumped. Suggestions?

 

[zanegrey]

have starter checked

 

[Jimmie Jazz]

have starter checked

Done. Even Replaced starter anyway. No change. Remember- this only happens after the engine is warmed up.

 

[zanegrey]

have bat checked .

check to makee sure you have a good ground to the block.

check positive bat cable at starter .

and check fusible links to see if they are over heating ..they get old and need to be replaced..

if all that is correct check timing...

 

[Jimmie Jazz]

have bat checked .

check to makee sure you have a good ground to the block.

check positive bat cable at starter .

and check fusible links to see if they are over heating ..they get old and need to be replaced..

if all that is correct check timing...

Okay, I'll do those things if you explain why this ONLY happens when the engine is warmed up? It NEVER happens when the engine is cold, or after a few hours of setting. I don't see how grounding, fusible links, timing etc. are affected by engine temperature. The engine is normal at any other time.

 

[rogoman]

When the motor is hot and doesn't want to spin, remove all the spark plugs. Now if the motor spins easily, then you've got a problem with the starting circuit. The starter may be bad or it's getting heat soaked from the motor.

However if it doesn't spin with the plugs out, then there's an internal problem with the motor.

 

[zanegrey]

heat make things expand ..

if you have a bad ground cable when it heats up it will resist more..

the same with any other electrical wiring..

and if the timing is a few degrees off it can cause to much compression at the wrong time..