As the title states I am having a hot start issue. I replaced the dummy plugs last weekend and put in fresh oil (synthetic rotella) and fuel filters. No change. Starts perfect when cold and runs perfect once running. Power is good and mileage hasn't dropped. Batteries are 1 year old.

I noticed that when it won't start hot on the first crank (has never failed to start on the second crank) I am not hearing the injector buzz. If I cycle the key off and on I hear the buzz and it starts immediately upon engaging the starter.

I'm thinking FICM possibly. But that's an investment I'd rather not make unless I was absolutley certain it was the problem. I have had an injector circuit low code a few times. Always injector 5. Has only happened when towing upwards of 12,000 pounds on very steep inclines. Not on the highway but steep backroads around here.

Truck is an 06' and has 125k on it currently. I know the FICM is original and no I have not done any testing to it yet.

On the bright side the inside of the engine is spotless. And the turbo compressor looked like it was brand new out of a box inside.

Another question. There is a little o-ring on the crankcase vent where it enters the valve cover. When I pulled the vent out the o-ring was swollen ad there's just no getting it back in right. Does anyone know the trade size of this o-ring? I'd like to get a viton replacement for it.

 

check the ficm voltage. also moniter icp while cranking durring the concern.

 

As mentioned, monitor FICM voltage. FICM has to have 48V to operate properly. Check for DTCs again. Most of the time if the FICM is bad, it will set a DTC for all 8 injectors having low voltage circuit issues. Although, there is a TSB from Ford about the FICM's DC-DC converter not properly converting to 48V. It will set a P0611 or various injector circuit codes. Make sure there is not any oil leaks? What wieght oil are you using? The injectors require 500 psi before they will fire. Alot of hard start when hot issues are due to inadequate oil pressure. As you mentioned, it will start fine the second crank bc you have already cranked and built up oil pressure. Although, I'm not gonna rule out injectors though. I'd start with oil system check (pressure, leaks, ect). Make sure everything is ok from there. Then check for DTCs as mentioned. Post with your latest info and we'll go from there.