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Help Support Hardline Crawlers :
Truck won't idle
- Thread starter mudmaster
- Start date
deerlick
Well-Known Member
ficm
Lucky Jeff
Well-Known Member
Wiggle the connector at the back of the FICM? Pretty sure that just because it's seeing 48 volts, doesn't mean it hasn't gone bad. It's real common for those things to fail. Hopefully Hiwater or ChopTop can chime in. It's been a few years since I've had to mess with one of those things.
zukkev
Cornfuzzled yet again...
It can and will...Have witnessed/ replaced stuck/electrically failed EGR's that cause all sorts of unhappy idle problems, not to mention it doesn't run so hot goin down the road either! ... That said, I have also seen my fair share of failed FICM's due to low voltage, BUT in my experience, if the scn tool shows 48V chances are the voltage side of the FICM is ok, but that's not to say there isn't another issue with it...
Lucky Jeff
Well-Known Member
If I ever decide to replace the Burb with an Excursion, it will be a 6.0. And I will keep a spare FICM under the back seat :haha:
No it won't.
Im still leaning towards fuel pressure. These trucks will barely run with no fuel pump, but will smoke, shake, and wont rev out. Fuel pressure is the one thing ford doesnt monitor, so a scanner wont find it. So if the truck technically runs, and no check engine light, I'd start with fuel issues. Plugged filter? bad pump? plugged pickup tube in tank?
are you able to look at things like injector oil pressure and ICP duty cycle? You could have lost an o-ring on an injector, and getting oil into your fuel and causing the blue smoke.
Pull the dipstick and make sure your not down on oil, and that your not MAKING oil with fuel getting into the crankcase.
Pull the dipstick and make sure your not down on oil, and that your not MAKING oil with fuel getting into the crankcase.
zukkev
Cornfuzzled yet again...
Is it using coolant? Blown EGR cooler?
Those seem high, but if the engine is cold, and running rough, that could explain it. Usually in the 500 to 600 range pressure, and 20% or less on duty cycle.
I still think you need to rule out fuel pressure. These trucks can syphon just enough fuel from the tank to run, but it will be very rough, and wont rev up at all.
The fact that the truck runs at all almost eliminates most electrical problems and puts you on a physical problem troubleshoot.
One thing you could try is to disconnect the ICP sensor. Just unplug it, so the truck doesnt get pressure feedback. it will set a check engine light, but then default to an open circuit limp program with fixed IPC and IPR commands instead of feedback commands.
if it still runs rough, then Im thinking bad o-ring on an injector, or a stuck open injector allowing you to lose hpop pressure, no fuel pressure, or some other mechanical failure.
I still think you need to rule out fuel pressure. These trucks can syphon just enough fuel from the tank to run, but it will be very rough, and wont rev up at all.
The fact that the truck runs at all almost eliminates most electrical problems and puts you on a physical problem troubleshoot.
One thing you could try is to disconnect the ICP sensor. Just unplug it, so the truck doesnt get pressure feedback. it will set a check engine light, but then default to an open circuit limp program with fixed IPC and IPR commands instead of feedback commands.
if it still runs rough, then Im thinking bad o-ring on an injector, or a stuck open injector allowing you to lose hpop pressure, no fuel pressure, or some other mechanical failure.
Well, that kinda rules out a bad ICP sensor to me. I still think your fighting a fuel pressure issue. its the one thing the computer has no sensor for, so wont throw a code.
There is a pressure test port on the side of the fuel filter housing, but you need a metric to NPT adapter in order to get any test equipment to connect to it.
There is an updated fuel pressure regulator spring from ford, and there have been problems with the wiring harness going into the fuel pump. Check the connector.
There is a pressure test port on the side of the fuel filter housing, but you need a metric to NPT adapter in order to get any test equipment to connect to it.
There is an updated fuel pressure regulator spring from ford, and there have been problems with the wiring harness going into the fuel pump. Check the connector.
Is the pump turning on tho? It should run for several seconds on initial key up, then shut off until you begin cranking the motor over. Although even if its running that doesnt rule out problems elsewhere in the fuel system.
Sorry to sound like a broken record, but fuel problems are the one thing that wont show a code. You can chase the computer around all day with every scanner on the planet and not get the info that a pressure gauge on the bowl will show. Almost every other problem on these powerstrokes will pop up some sort of code, and your not getting any that Im aware of.
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