Hot Start Problems

My 1984 Chevy 1/2 ton 4x4 will not start after the engine gets hot. It is a

5.7 liter. The starter will not crank the engine. I have replaced the starter (twice), alternator and battery to no avail. Can someone help me solve this problem?
Reply to
rogerr
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Does it like try to crank but very slow?

Reply to
SnoMan

Reply to
David Norris

Yes, usuaaly it will crank but very slowly as though the battery were low.

Reply to
rogerr

Yes it will usually crank but very slowly as though the battery were weak.

Reply to
rogerr

First thing to do is check the timing. Too far advanced will make a hot engine not start. Check the initial, running & if all else fails the cam (ie make sure your timing marks on cam and crank line up with not chain slop). Charles

Reply to
Charles Bendig

Thanks for the timing suggestion. It appears to have worked.

Reply to
rogerr

Ignition timing has nothing to do with how fast or slow a starter cranks when the engine is hot or cold. Your problem is likely caused by bad battery cables/connections, especially the main ground. Check all cables for corrosion and clean all contact points.

As temp increases so does resistance, so what's happening is your marginal connections are fine when cold, but don't flow enough juice when hot and the resistance is higher.

Doc

Reply to
"Doc"

I just wanted you to know I had a 72 nova that i put headers on and it cranked slow i thought the starter was over heating,reset the timing and it started fine. Bobby

Reply to
bobby swift

Retarding timing for easier HOT starts is a OLD Demolition Derby trick. Basically when a Engine is past XXX degrees it spins over slower then it does at ambient.

A heat soaked, weak, or dying starter compounds this problem. As does a weak battery.

Now when it comes to Old SBC's over the years timing chains can streach, heads can crack, starters lose there "ass"( or some jason puts a low torque in place of a high torque). If the timing is advanced for say 92 or 93 Octane, and the truck is running on 87 Octane, with worn parts, Retarding the timing some will help it start better.

Charles

Reply to
Charles Bendig

I'm not saying it doesn't work, I'm just saying it's band-aiding a problem caused by something completely different. The ECM assumes base timing is set correctly and advances from there in closed-loop, so if the base has been bumped down a few degrees it's going to be running less advance once started, causing decreased performance and fuel economy.

All he needs to do is clean/replace the battery cables and connections and he'll be good to go, with the timing set correctly.

Doc

Reply to
"Doc"

It's a 1984 1/2 ton. That means CCC & CST Distributor. The engines still can having timing advanced or retarded for fuel grades. The CCC (Computer Controlled Carburator) is known for having Choke issues.

Those engines use vaccume & Computer controlls that basically fight each other. A bad vaccume line, or someones attempt at circumventing the emmissions controlls can make them run like total crap. Charles

Reply to
Charles Bendig

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