I have a 2003 5.4 7700 w 108k on the clock. It has a starting problem since I bought it about 15k miles ago

The problem usualy occurs if I leave the truck for more than a day and try to start, I have to crank and crank to get it going

It doesn't want to start basically I have to keep cranking it and hit the gas pedal
When it does start the engine stumbles and misses then finally an unholy amount of dark smoke comes from the tailpipe and its good!

After that first start it usualy runs fine and starts normally for the rest of the day so its hard to take it to a shop and repeat the problem in front of a mechanic!

I have also had the code P0147 lean codes and EGR codes when towing (5000lbs+) this is a list of stuff I have done:

New plugs at 100k
Replaced fuel filter
Run plenty of injector cleaner thru it.
Replaced the O2 sensors.
New Battery
Cleaned MAF sensor (might be due for another clean)
Replaced the DPFE sensor.
Replaced the 90 on the back of the intake manifold and PCV tubes.

I am not sure if the codes are gone now since they only occur when towing I am wondering if the starting issue is related to the lean codes and a vacuum leak somewhere I have not checked?

I still like this truck a lot I just need to get this issue fixed!!

 

how long does it take for the extended cranking before it fires?

My red truck does it (cranks about 3 or 4 seconds) every now and then if i rush the key cycle. I usually try and let the key sit in the on position for a few seconds before i crank so it can prime the fuel system.

 

If it's blowing black smoke it's flooded. You may have leaky injectors. To clear the flooding, hit the pedal all the way to the floor and that shuts the fuel off.

 

..I see several issues in your discription.
.First the 147 code is a heater circuit issue for bank 1 sensor 2.
.Comment: This is not normally an issue during cold start as the OX sensors have no input to the system at cold start, especially sensor #2.
.Second, the black smoke after finally starting, tells us the cylinders had loaded up with fuel for some reason and a long crank time has cleaned them enough to fire.
.Note that throttle application does not add fuel at startup like a carbed engine but will do something most are not awhere of.
.With a rich or flooded engine, holding throttle wide open will shut fuel off and clear the cylinders of fuel by passing only air through the motor with ignition still working that will begin to fire once the plugs are cleared..
.
.Here is what I would do to get started on the long crank issue and flooding.
1. check fuel pressure for being in the 38lb +/- 5 range.
2. clean the IAC to be sure it's not sticking closed when last hot.
3. check engine temperature for thermostat operation and CHT sensor.
These items have direct impact on cold starts.
.
..What happens at cold start: Key to run only, the PCM looks at the values of the CHT and the IAT to tell the PCM what the setting will be for fuel and ignition plus opening the IAC for raised idle.
..The fuel pump runs about 2 seconds then shuts off.
.
..At crankover, the front crank sensor tells the PCM of rotation and turns the fuel pump on again.
..Check the crank sensor plug for being seated by pulling off and back on.
..Somewhere in all this you should find the problem. If crank sensor is not sending any rotation info, nothing happens with the motor for fuel or igntion..
..EGR codes may or may not be involded in cold start depending on if the EGR is open a bit for any reason. Usually not because at crankover there is no exhaust to get back into the intake so the small amount of extra air would not make that much difference.
..Still need the EGR or any other codes to address the remaing isues.
Good luck.

 

thanks everyone i am gonna check thru all these and will report back
I got the wrong code numbers the truck throws P0171 codes when towing usualy 15-20mins after I stop to fill up with gas!? hopefully the PCV plumbing and lines upgrade fixed this though

 

i had the same issue. mine would do it after sitting 8 plus hours. mine was bad injectors. i did the run around for nearly a month trying to nail it down. you do run the risk of hydolocking the engine or flooding the crankcase overtime with fuel and thus spinning a main or rod bearing. if you can swap your injectors with a known good set and see if it helps.

imho the amount of black smoke you speak of sounds like more fuel is being introduced at startup than the computer can deliver, that is what makes me think possible fuel injector failure.

hope it helps.

 

I went to investigate the IAC and ended up going nuclear and pulled the whole throttle body off and cleaned it, cleaned the MAF sensor again and IAC.

It feels a lot better now, feels like it has more power, starts right up
hopefully this has cured the issues but I will have to wait a few weeks or starts to see if it comes back and till I tow again to see if the Lean codes are fixed

the throttle body was filthy