Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Ford 6.8 v10 starts normal when hot very hard star
Hi all.
So here we go. Working on a 2004 ford e450 stepvan with a 6.8 v10 in it. Truck starts up no problems in the morning after sitting. When truck gets well into operating temperature, it doesn't want to start. No codes at all. No freeze frame data. Fuel pressure is at a steady 50psi at cold and hot. Fuel is getting to injectors when hot and so is spark. Only way the truck will start back up again, is if you hold pedal wot. Then a nice black cloud of smoke come out like I'm rolling coal. Now another issue arrived yesterday, very high idle when hot. It has a new idle air control valve on it, with no vacuum leaks. Someone shoot me, or help out. Lol
Thanks in advance.
With the engine hot, key on engine off, does that pressure hold steady? Thinking possibly an injector leaking when hot.
I also would check generic global ob2 scan data for an extra pid to to see if it's reporting correctly.
Yes fuel pressure holds steady, also checked for any additional PIDs and nothing is there on OBD. Im practically bald at this point from pulling my hair out.
Oops. Posting from my phone, that should have read ECT pid, not extra pid. I'm wondering if the temperature is being reported correctly to the PCM. The fact that holding the pedal to the floor started the truck with clouds of black smoke no less, suggests to me that the mixture is to rich.
Oops. Posting from my phone, that should have read ECT pid, not extra pid. I'm wondering if the temperature is being reported correctly to the PCM. The fact that holding the pedal to the floor started the truck with clouds of black smoke no less, suggests to me that the mixture is to rich.
Generic data would be preferable to manufacturer data because there will be no substitute values
Hey Aneves! I'm curious to know what your fuel trims are, cold and hot. Preferably when the idle is high, too.
Are you looking at Global scan data? I ask because these will use a cylinder head temperature sensor instead of a conventional ECT for fuel control. Global data doesn't allow for substituted values, like Noah said, but they WILL allow for converted values.
Another thing to check would be rationality between the IAT and the engine temp after sitting overnight. They should be nearly identical.
the first thing that came to mind before reading Noah reply was the ECT sensor. Also the high idle when hot suggest that too. bad ECT sensor and or connector/Wiring issue
