I'm having a problem with a hard start after the car sits and the temp goes up a little (10 - 20 degrees F) from regular running. At the most it gets to around 180 degrees from sitting for a bit before cooling down. Sometimes it will take an attempt or two to get it to start and sometimes on the first try it tries to eat the flexplate with a kickback. I think it's too far advanced but it's around 11 degrees initial and shouldn't be kicking back like that and giving a hard start at that range.

Any ideas that maybe I'm just not thinking of?

 

Is it slow cranking? Could be a starter "heat soak" problem.
Or does it crank fine, but just doesn't fire right up?

 

Nah, it's not a heat soak problem. The starter turns fine. Something I didn't mention is that I had to disconnect the vacuum advance on the distributor since it blew out the diaphragm. This was around the same time it started doing this. I don't think that's it though since all that would do is advance it if anything and make it even harder to start. I just disconnected the hose and blocked the vacuum ports.

 

No, the vacuum advance wouldn't have anything to do with a starting issue. The way smog era engines are set up, NO vacuum comes out of that advance hose at idle. It only gets vacuum after the throttle plates open with the engine running. The car will drive like a dog in the low to medium rpm range with the vacuum advance disconnected though.

 

Ha ha, yeah, I was pretty sure it's not the vacuum advance. I keep going over in my mind what I've done since this started happening and there isn't a whole lot. I do notice that I have no launch now with the vacuum advance gone.

I did put my car up on some high ramps and cranked it a little while ago. When I crawled under there was a slight wobble to the flexplate but I couldn't tell if it was due to engine vibration or if the flexplate is warped. I'm going to let it cool down and check the bolts to make sure they're all still torqued correctly. I used an impact gun when I changed out the torque converter a while back and maybe it didn't tighten one or two down tight enough.

 

What ignition are you running, and how do you have it wired up (supply to coil)?

 

Just a standard HEI setup, nothing advanced.

 

I think I figured out what it was. One of the starter bolts had cracked and gave it up and down movement of like .050 of an inch. Pulled it and put in an older starter bolt I had and it stopped doing it. Apparently a grade 8 bolt wasn't too grade 8 and flawed in the metal.

So, I've replaced that. Let it sit and idle to warm up, turn it off, crank it immediately and no problem. Do the same thing but let it sit and build up heat for a bit and starts with no problem. Just took it out and got gas and started with no problem. Seems like that fixed it.