I need to replace my fuel filter in an attempt to diagnose a pinging problem (cleaning the MAF didn't have an effect). I looked in my Haynes manual and it talked about using the impact sensor thing to disable the fuel system and crank the engine or to bleed the pressure off with a pressure tester. I was wonderind, couldn't you just pull the fuse for the fuel system and crank the engine? Just curious. Thanks in advance.

 

If you don't mind havin a little fuel squirt in the engine bay, there's a schrader valve on the fuel rail (I know there's one on the passenger side, not sure about driver side), towards the back sitting on the top of the fuel rail. Undo that to let off fuel pressure. Not sure if it will relieve pressure back at the fuel filter, but it definitely will in the fuel rail.

 

make sure disconnect the battery also to eliminate the possibility of the fuel pump turning on. Do what fbodyfan said and relieve pressure at the schrader valve and you will be good to go!

 

makre sure to keep gas away from electric components...as it can lead to a fire ...very important.....this doesnt do with wut am talking about but knew this guy who spraid carb cleaner while having cigar on....he fried he's face and had to get recontruction...

 

Just did the fuel filter, pulled the fuel pump fuse, cranked engine, (it started momentarily). No pressure at all when I pulled the lines of the filter. Of course, it is located beneath the truck mid way back so there is no possibility of electrical fire as mentioned above. SOme gas dribbles from the lines when disconnecting and from the filter so have some rags handy and wear some safety glasses.

 

Oh and by the way, I've tried everything for the pinging besides replacing the exhaust, MAF, Spark plugs (FOrd plats), all filters, seafoam, EGR cleaning (which helped power but not pinging). She runs as smooth as ever, however nio change in the pinging. 89 octane helps alot, 92 octane and it is gone. If you figure it out please post the solution.

 

I bet the EGR ports are clogged.

 

Thanks for the replies! I'll give the fuel filter a shot this weekend and maybe try cleaning the EGR ports. How would I go about that?

 

Was the problem there when you got the truck? How long have you had it? (just goin out on a limb as to a possible solution) could there possibly be a tune or program (requiring higher octane fuel) in that you don't know about?

 

No, I have this truck (97 supercab 4x4) since new, the pinging gradually developed over the last few years. It has been very well maintained. The EGR ports and throttle body are sparkling clean, did that last month. Cleaned MAF sensor, replaced all filters, new plugs/wires, took it to the dealer, they had no solution.Pretty well at the point were I will throw in some high octane and trade it in, pity as it runs well otherwise and has only 85, 000 miles on it. I've had very few problems in general beside the usual stuck discs and drums, crack door, seam weld rust, A/c issues. The pinging is pretty common as found on this forum and on other f150's i've driven. No one has come up with a real cure. However puling up a hill with 87 octane it really pings hard and if I tow my 2000 lb tent trailer up a hill the engine sounds like it may blow up. The higher octane (91) cures it nicely, but that gets expensive and a little old, espceially when my V6 Toyota Camry can rip that trailer up the hill with no problem.
I may try replacing the cats before dumping it, but would like any feedback from others who may have tried this as a solution..

Thx.

 

Replaced the fuel filter, took it for a drive and there was still the pinging but it was better. Since the last time I posted it had started throwing codes for EGR underflow. Got it pulled apart and it was almost completely plugged so cleaned the passages and replaced the EGR valve. I was done to about an 1/8th of a tank, filled it up with regular and tried to lug the engine as much as I could and ... no pinging and no codes. Thanks for your help!!!

 

just a thought, but maybe try n replace the knock sensor under the intake? that sensor should retard the timing if any spark knock occurs, had that problem in my old 92 f150, 300 inline... sensor should be only thirty bucks or so. if that sensor's FUBAR then the computer doesnt know its pinging... everything else sounds fine..................josh...