'84 Z28 won't crank when hot, does after cooling
 

First, a little history. I'm in the process of restoring my wife's Z28. It's the 305 5.0L HO engine. It sat for 13 years until recently. I had to change the fuel pump and rubber hoses from the steel tubing to the fuel pump. Got it running, and it runs great. My wife informed me that everything worked on it when it was initially parked. Since I've gotten it running, I have not driven it. I need to put a new set of tires on it, and I need to put new tabs on it. So, everything I've done up to this point has been in the driveway with the car sitting on jackstands.

Like I said, it runs great when it's running, and it will crank right up when the engine is cool. I ensured there was water in the radiator, but I haven't flushed it or put new antifreeze in it, yet. It idles great. Problem is, when I turn it off and then attempt to turn it back on, it acts like the battery is going dead. At first, I thought it was the battery. After all, it's 12 years old. The alternator appears to be working. I checked the output voltage, and it's around 13.5 - 14 VDC. I was putting the battery back on the charger thinking the alternator wasn't keeping it charged. But then, I took a known good battery and tried it. Same thing was happening after I turned it off after letting it idle and get hot. So, I figured that maybe the starter is giving me fits. I've seen starters work intermittently, before. They'll work fine when the engine is cool, but act like they're dying when the engine is hot.

I'm not all that familiar with Chevy's, so I've been doing a lot of reading. I've read that it could be the battery and cables, possibly the starter needs replacement, or maybe it's a vaporlock issue. Like I said, before, my wife informed me that the car ran great before it was parked. Personally, I think it's the starter, but I want to hear what anyone else thinks before I go off spending money.

Re: '84 Z28 won't crank when hot, does after cooling
 

No crank when hot is usually the starter.

Re: '84 Z28 won't crank when hot, does after cooling
 

Sounds like a starter to me too. My truck was doing the same thing. Starter gets heated up from the exhaust then won't work again until cool.

Re: '84 Z28 won't crank when hot, does after cooling
 

That's what I'm thinking. In between the time I wrote the first post and this response, I got in the car after it had cooled down a bit, and it cranked right up with the 12 year old battery. And, the battery had not been on the charger. I live in Seattle, and the ambient temp has been in the mid 60's for the past several days. I live on a hill which is about 450 ft above sea level, so I'm finding it hard to believe that it's a vapor lock issue. Additionally, the car has not overheated since I've been running it.

Oh well, guess I'll slap a new starter in it and see what happens.

Re: '84 Z28 won't crank when hot, does after cooling
 

Vapour lock isn't going to prevent the engine from cranking.

Re: '84 Z28 won't crank when hot, does after cooling
 

I just want to add that even tho your battery is still ok by the sounds of things I would not expect it to last too much longer. I live just a little north of you right near Vancouver B.C. Our climates are very similar and we seem to have an average battery life of 5 to 7 years depending on quality of battery.

Re: '84 Z28 won't crank when hot, does after cooling
 

Hot start problems on SBC are well documented ; an aging starter with worn solenoid doesn't help

http://www.streetrodstuff.com/Articl...tart_Problems/
https://www.thirdgen.org/solenoid
http://www.superchevy.com/how-to/148...-no-start-fix/

Re: '84 Z28 won't crank when hot, does after cooling
 

possible heat soak in the starter? Heat shield could work

http://www.summitracing.com/parts/tay-2543/overview/

Could be heat getting in to the fuel lines. Its common with old Pontiacs.

Re: '84 Z28 won't crank when hot, does after cooling
 

It's been a little while since I've done anything with the Z as I've been pre-occupied with other things all summer. Anyway, my wife informed me that her ex-husband purchased a starter with a lifetime warranty back in '94 at Schucks (now O'Reilly) here in Seattle. She still had the receipt after 20 years. lol. (She saves everything! In this case, it was a good deal.) I pulled the starter, took it back to them, and they gave me another starter with it's own lifetime warranty. I installed the new starter, but I ran into another, different issue, afterwards. I expect to have that straightened out within the next couple of days. I'll report back and let everyone know if the hot start issue was actually fixed or not by replacing the starter.