1996 F150 hard start when warm. P0171 and P0174
#1
1996 F150 hard start when warm. P0171 and P0174
Hey guys my dad has a 96 F150 XL with a 300 6cyl. has lean codes PO171 (lean bank one) and P0174 (lean bank two). When cold, it cranks just fine and runs just fine but when its be ran for a while it hard as hell to start...it staggers and knocks real hard. Dad has to press the gas pedal to get it to straighten up after a few seconds. We've replaced the intake gasket, MAF sensor and EGR valve. There are no vacuum leaks and smoke test didnt show anything. PLEASE HELP!!!!!
Last edited by Iceman_AKA_Ford guy; 05-06-2010 at 02:58 PM. Reason: added more info.
#2
First of all did you disconnect the neg. battery cable when replacing/cleaning any of the electrical/sensors/parts? This step is a MUST.
If you did not do the above step, try it, wait 5 minutes, reconnect and take the truck for a drive to reset the computer. Let us know
Did you repalce the O2 sensors?
How did you get codes? Any pending codes?
I wonder if the DPFE is not sending the correct signal to the computer.
Miles on the odometer?
If you did not do the above step, try it, wait 5 minutes, reconnect and take the truck for a drive to reset the computer. Let us know
Did you repalce the O2 sensors?
How did you get codes? Any pending codes?
I wonder if the DPFE is not sending the correct signal to the computer.
Miles on the odometer?
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#13
I have the same pickup with the same problem but my truck has dual tanks when i start it hot on the front tank it shakes and skips like hell but if i just flip the tank switch to the rear tank the truck smoothes right out compared fuel pressure between frt and rear tank and frt is 7lbs lower also if i reset the ck engine light and just run on the rear tank the truck runs fine and never sets the codes or light again hope this helps Irv
#14
I have the same pickup with the same problem but my truck has dual tanks when i start it hot on the front tank it shakes and skips like hell but if i just flip the tank switch to the rear tank the truck smoothes right out compared fuel pressure between frt and rear tank and frt is 7lbs lower also if i reset the ck engine light and just run on the rear tank the truck runs fine and never sets the codes or light again hope this helps Irv
#15
Did you ever figure out the problem? We have had a couple of warm days here this past week in MD and my 96 with 144k is starting to do the same thing! Won't start after being run unless I gas it, but if it's been sittin it'll start fine. I was thinkin fuel pressure regulator but I don't just want to throw parts at it and not solve the problem. I appreciate any help. Yes I know this is an old thread, just curious to see if the problem was ever solved before I start a new thread.
1996cyl
In the couple months I have owned this truck it has caused nothing but problems and an empty pocket. I bought a six for reliability...
1996cyl
In the couple months I have owned this truck it has caused nothing but problems and an empty pocket. I bought a six for reliability...