major stumble/hesitation

[fordfirsttimer]

This is the first ford ive ever bought and im having a little problem with it. Ok its a 4.6l vin code 6. i test drove the truck before i bought it and it ran smooth shifted fine doesnt leak anything. when i test drove it the gas gauge read almost empty. i filled it with gas after purchase and thats when i noticed it was idleing rough but not stalling out still hasnt stalled out. as i accelerated steadily it stumbles and shakes through the beginning of every gear but when at the top of a gear its smooth. Also its not smooth but less hesitant and feels a lil underpowered when under hard acceleration. The check engine light is on but only reads a egr vavle not working properly. i changed that and no difference in the running condition. i pulled all the plugs and they looked fine but were not properly gapped so i regapped them still no change. the only thing i didnt do was check/replace the coils. i ran a whole tank of gas through and filled it up with a lucas oil fuel system additive and it seems like every so often it will try to smooth out but then goes back to stumbling. any help would be greatly appreciated for this first time ford owner.

 

[BANGEREXPO76]

Welcome to the site.

You probably should have changed the plugs since you had them out as well as checking to make sure each coil is funtioning properly. Check your PCV valve and the hose that goes from it to the back of the intake. That little elbow gets a hole in it and lets vaccum out. Those will cause a problem. Just changing the egr valve is not enough. You must take that throttle body off and clean out the egr passages as well. They get gunk in them and throw the code. Good luck getting it together.

Banger

 

[fordfirsttimer]

I checked all the vaccum lines and the only thing i noticed is that the line that runs to the egr valve didnt have suction more like air vibrating through it. am going to change the plugs but dont think they are the problem as they didnt looke fouled or oily they still looked fairly new. i will take the throttle body of and clean it all out to see if it clears anything up. could it be gunk/condesation that built up in the tank because i am not sure how long it sat with a small amount of gas in it.

 

[MUSKYMAN52]

Could be bad gas, i had that problem, throw some octane booster in it then on the next tank sea foam and it should be good, its a misfire from bad gas, well sounds like it anyway

 

[Lightnig]

What is the code you are getting? Most parts stores will read the codes for you for nothing.


I must say though, it sounds like you are getting the same behaviour from you truck that I did (The rough/crappy idle, stumbling on acceleration, and feeling underpowered) before I changed out my PCV and hose. I would double check that before going any further...

 

[fordfirsttimer]

the only code i got was a p0101 i believe and that was it for the egr vavle i check the vaccum hoses like three or four times no hissing noises or anything that looked cracked or broken. ive been workin on my own cars since i was to young to drive so i know the basic stuff to look for and the only thing that stood out was that the vaccum line to the egr was more of like a small air pump vibrating the air out slowly than any real suction or pushing of air. i have a can of seafoam that i plan to add top the next tank of fuel hopefully that will give me a clue to whether its fuel delivery or something else but im always open to suggestions any help is good help.

 

[BANGEREXPO76]

If the EGR line is not giving you proper vaccum and its throwing an EGR code that is definately leading you in the right direction of the problem. Look at that line and connections thoroghly.

 

[fordfirsttimer]

well i figured out what it was turns out it was just dirty gas. ran three full tanks of fuel and a can of sea foam and runs like a top now. thank you for all the help i appreciate it.

 

[BANGEREXPO76]

Musky your the man!!!!