I have a 96 Topkick with the Cat 3116 HUEI 230hp ( yes it is a HUEI ) , 881,000 km . It stood all winter , went here the other day cranked it over a few times and it fired up no problem . It is a very easy starting motor . Obviuosly the fuel does not drain back etc cause it starts easy and runs very even , no smoke cold or hot. The heater works OK too. Could not ask for a nicer sounding or starting engine with that mileage. Say let it run 10 minutes just warms up abit , stop it , and it will restart immediatley no problem nice even . Let it get to operating temp , drive it for hours etc it runs nice , shut it off and immediatly try but it will not fire nothing, no smoke just like no fuel. Wait for maybe 20 minutes to 1/2 hour go hit the key and it fires instant and runs nice even no smoke as if nothing was wrong. Can run it as long as you want ,lug it etc it is smooth no issues. Shut it off hot and again it will not fire till it cools down abit. Shows no codes other than 55 which states no faults. Just all of a sudden started doing this no start when hot. Filters are new , fuel line pressure is in specs . Today when it would not start hot I pulled the plug off the IAP sensor but it still would not start ( read someplace that is a test if the IAP is faulty ) . It sure sounds like a sensor or ECM is cutting off power or fuel when hot only to start but yet it will run all day no problem or cold/warm start no problem . Any ideas where I should look to find this bug ? I don't believe it would be the pump , fuel supply is not leaking air , injectors always fire quick and smooth , it never smokes . It is no powerhouse but if compression was bad it would not start so easy as a rule and sound nice , oil comsumption about a liter in 5000 km. will hit 2800 rpm if lucky , boost varies all over but highest ever seen was 18 , oil pressure hangs around 50 psi (350kp) highway. Any ideas appreciated.