6.2 NA wont start when hot

[kennyw]

Higher viscosity would actually make a worn out pump work better, not worse since it could handle the increased clearance and give you more pressure than thinner fuel. I'd also venture to say your dealing with water or other contamination.

 

[skark_burmer]

OK i need to talk to you about vegie oil!!
I am starting out and need help on what you have done!
Sounds like I have the same problem.
Except I can start it cold, drive like 10 miles and loose power, shut it off for 10 minutes and it starts up and runs for another 10 miles.
Is it my filters clogged up, or a bad IP?

That sounds quite a bit different than my issues so i'll just be guessing here.
Check your filters, they might be clogged and starving your engine. Thats my best guess because if your IP was bad it wouldnt run at all, or the issue would get worse when its heat soaked, but would continue to run if cool fuel was going through it.
Like i said though, im just guessing.