I have an 88 f150 302 5-speed 4x4. when the motor is cold, it pops through the breather if you open up on it. I have changed plugs, plug wires, distributor cap and rotor,fuel filter, fuel pump, and set the timing. I used motorcraft plugs, Ford Racing 9mm wires, accel cap and rotor, and motorcraft fuel filter so i used all quality parts. It still does it and i dont know what else to ckeck or replace. any help would be appreciated.

 

bump
anyone have an idea? i really need help
thanks

 

is it still SD?

 

what do you mean SD?

 

bump

what do you mean sd?

 

speed density...MAP and my younot knowing what SD is i take it that it is SD

 

my reason behind asking is that ive heard, haven't experenced it, but have read on here that when you start giving these stock motors more spark they dont want to run right but your problem could lie somewhere else...just a thought

 

o yeah..........its still speed density...........i know what it is just didnt know the abbreviation

 

oh ok well maybe you'll get some more bites from someone that has more info but i gave my only thought sorry i couldnt be of morre help

 

thanks for tryin

 

im considerin takin the smog pump off and seein what that does. i took the K&N intake off of it and it helped it alot but it still runs a little rough when its cold and also if your in a high gear at low rpms and open up on it it runs a little rough

 

it almost sounds like its starving for fuel.. dose it seem to be poping at the intake or in the exaust?

 

definently the intake
it was real loud with the K&N setup
it sounds fine through the exhaust
it has a new in tank pump but i havent replaced the high pressure pump on the frame
today coming home i had it at 3k rpms all the way (about 20-25 mins) thinkin maybe something was just stopped up because it had been sittin a while so i thought i would see if it helped it seemed to maybe be better im not sure but it got a little hot right before i got home but cooled back off by the time i got home
i dont know whats wrong with it its killin me not bein able to fix it

 

if its in the intake then its deffanitly running lean,

if your thinking high presure pump, get a gauge and check the fuel preasure. Because i had to replace the high preasure pump, and it wasn't cheap, about 105-110 bucks somewhere in there, so i would surely check the fuel preasure before spending money on parts that you dont need...105-110 bucks can go somwhere else other than un-needed parts..
do you know how to check it?

 

im thinkin my gas tank is not venting because you have to put gas in real slow or it spits it back out so i think the tank might be vapor locking and starvin it for fuel thats what im gonna try next