Bad Hesitation When Heat Soaked

[Rx-7fetish]

'86 N/A
Mods: Racing beat header double wrapped, RB presilencer wrapped, emissions removed.

The car runs and pulls great until it gets very heat soaked. At that point it starts cutting out. At low throttle it kind of bucks, at high throttle it almost starts coasting and gets quiet as if nothing is working at all (although the rpms don't change at all).

Example 1: Friday I was on the interstate going "the speed limit" with no hesitation issues for about an hour (was pretty hot out). I got to a large mountain and it started hesitating to the point I had to slow down. After the downside of the mountain it was better. About 30 minutes later it started hesitating. In 5th gear I couldn't give it more than about 30% throttle and go over around 70.

Example 2: I was at Talladega on Saturday and had two 20 minute runs with about 35 minutes between them with no issues. On my 3rd run it started after about 5 laps. It initially began as cutting out in turns (both direction), and eventually it was cutting out to the point I had to pull off. At this point I had about 2/5ths of a tank of gas.

Example 3: On the way back from Deals Gap it started doing this and go to the point I couldn't even rev it past ~4k in neutral.

I would normally think 3800 rpm hesitation but revving in neutral shouldn't even engage the secondaries. Someone suggested maybe the fuel pump was getting too hot on a lower tank of gas but it did it on Saturday even with a full tank so I'm thinking that would rule it out. I also thought maybe the pump sock was dirty (normally making it cut out turning in one direction), but it did it in both directions and on a full tank of gas.

The car was also mostly fine on the way home this weekend as the temperatures were much cooler. If I tried to punch it the car would buck a little, but anything under about 70% throttle was fine.

After the Gap but before Talladega I reground the entire engine bay. Quite a while ago I added a boost sensor ground (to fix the 3800 rpm hesitation).

Ideas?

[My5ABaby]

'86 N/A
Mods: Racing beat header double wrapped, RB presilencer wrapped, emissions removed.

The car runs and pulls great until it gets very heat soaked. At that point it starts cutting out. At low throttle it kind of bucks, at high throttle it almost starts coasting and gets quiet as if nothing is working at all (although the rpms don't change at all).

Example 1: Friday I was on the interstate going "the speed limit" with no hesitation issues for about an hour (was pretty hot out). I got to a large mountain and it started hesitating to the point I had to slow down. After the downside of the mountain it was better. About 30 minutes later it started hesitating. In 5th gear I couldn't give it more than about 30% throttle and go over around 70.

Example 2: I was at Talladega on Saturday and had two 20 minute runs with about 35 minutes between them with no issues. On my 3rd run it started after about 5 laps. It initially began as cutting out in turns (both direction), and eventually it was cutting out to the point I had to pull off. At this point I had about 2/5ths of a tank of gas.

Example 3: On the way back from Deals Gap it started doing this and go to the point I couldn't even rev it past ~4k in neutral.

I would normally think 3800 rpm hesitation but revving in neutral shouldn't even engage the secondaries. Someone suggested maybe the fuel pump was getting too hot on a lower tank of gas but it did it on Saturday even with a full tank so I'm thinking that would rule it out. I also thought maybe the pump sock was dirty (normally making it cut out turning in one direction), but it did it in both directions and on a full tank of gas.

The car was also mostly fine on the way home this weekend as the temperatures were much cooler. If I tried to punch it the car would buck a little, but anything under about 70% throttle was fine.

After the Gap but before Talladega I reground the entire engine bay. Quite a while ago I added a boost sensor ground (to fix the 3800 rpm hesitation).

Ideas?