I have 95 f150 4x4 4.9 5spd.My truck pings a little when I floor it on the highway .My timing is at 10 deg BTDC .Jacobs electronics recommends I should set my timing to 14 deg BTDC. But I can’t do that now. It runs great when I first start it in the cold but loses power after it warms up .I can hear a very slight rattle almost like an exhaust leak or something (when floored) . Plus it is running really lean the plugs I had in before were only in maybe 2000 miles on them and they were fried. It running really hot (to much air) . What should I try first before I replace EGR ?

Just made the following Mod's: 29"Tires to 31",Jacobs ignition system,195 deg thermo to 180 deg,drop onr temp range on spark plugs,3:08 rear to 3:73,Active suspension adds 1500 lbs of payload

 

SOUNDS LIKE IF IT'S RUNNING LEAN ENOUGH TO FRY THE PLUGS, YOU COULD RICHEN THE AIR/FUEL MIXTURE A LITTLE. MAYBE THAT WOULD STOP THE PINGING DUE TO DETONATION OF THE PLUGS. I DON'T KNOW HOW TO DO THAT, BUT I'M SURE SOMEONE COULD TELL YOU HOW ON THIS BOARD. SORRY IF I'M NOT MUCH HELP.

 

the pinging that you are hearing is spark knock. when you retard your timing you need to run a higher octane fuel to eliminate premature detonation. this should solve your problem.
-marc (supercrew-far from stock)

 

I dont think the a/f mixture is adjustable on the 5.0s I believe your fuel inj system is the speed density type, meaning you do not have a MAF sensor. When was the last O2 sensor put in? I would say that or the TPS is the culprit. If you dont have a haynes manual its the best 10 bucks ull ever spend. it has a good troubleshooting section with specifics about how to test the sensors.

 

The O2 is brand new and I already tried 93 octane it did nothing.

 

Have you changed the fuel filter lately? If not, you could have a clogged fuel filter or dirty fuel injectors and hence, causing your lean condition. Change your fuel filter and add Redline Fuel Injector cleaner at your next gass fillup. Also, have you tried bypassing the Jacobs?

 

I suspect the EGR too but I would also disconnect the Jacob's ignition first just to eliminate it. Let us know what fixes it.

Dan

 

I'm with Blown2run. You're running way too lean. I'd do what he says and check the fuel delivery system. Find out what the fuel pressure should be and put a gauge on it to see if it's to specs. If you haven't done so, change the fuel filters. I'm unsure as to how many filters there are. Could even be a weak fuel pump.