93 GMC 6.5TD hard start when hot
 

I guess its been a while since I requested help here, but running to a little problem. I got 93 6.5td that doesn't like to start when the engine is hot. I had replaced the Injection Pump about year and half ago, I was about 800 miles away from home when I first noticed this problem. I guess for some reason I got some cold water over the IP and it started right up. I replaced the fuel filter, Oil pressure sender switch, and the lift pump. I still have the same problem, and the cold water does the trick. Is it the IP again after barely two years of rebuild? I mean when IP is operating poorly I should have bad milage right? I got 530 miles on a full tank, so I don't know, if some one has any suggestions please let me know.
:argh::argh::argh::argh:
Thank you

usually means the ip is going if it cant start hot but it does with cool water