Hello i'm new to the forums and I came here to look for answers to my problem but couldn't find one so I decided to start a new thread. So my problem is I have a 93 Ford F-150 5.0l 302 v8 and what happens is that when you put the engine under load eg. up hill the truck will start shaking and spitting out white smoke. The truck gets really poor gas mileage and has lost power. So far I have replaced the egr position sensor and egr valve, tps sensor, spark plugs and wires, and while replacing the plugs I noticed the eighth plug had its center electrode melted ,and fused to the ground electrode, and the rest of the plugs had white powder. After replacing the plugs, checking the timing I took it for a drive and it ran like new, so the next morning I took it to work (about one hours drive) it ran like a champ all the way there except up hill where it spat out white smoke so I switched it from overdrive gear to drive gear and the transmission switched gears and the engine revved after that the smoke cleared. After work on the way back the same thing happened so I stopped by an AutoZone and explained my problem to the clerk and he said that I should remove the ignition coil and the ignition control module to get it tested. Since I didn't want to wait I took them of right there and the guy tested them and they passed so now i'm stuck with the same problem all over again. I really want the truck running again any help would be really appreciated.

 

Sounds like your running way too lean.

 

*Most* of the folks that work at AutoZone, try as they might, really don't have a clue. Take away their computer and most of them couldn't get a weedeater fixed, let alone an entire truck. And their job is to sell parts. If they go out to a customer's truck, pull codes, and see a code saying a sensor is reading out of range, then they will try and sell you that sensor. Nevermind the fact that the sensor could be right and whatever it's monitoring really IS out of range due to a different problem... why do you think they read codes for free? Hint: to make $$$.

Check for codes.
Check ignition timing.
Check fuel pressure.

If you need a timing light or fuel pressure gauge, AutoZone will rent them to you for a deposit, which will be returned to you in full when you return the tools.

Don't replace parts til you have a good idea of what's wrong. The only thing I might change right away is your fuel filter, but that's just good PM if it ain't been done lately.

 

Yes exactly, plugs should be tan brown so the motor is very lean and since all plugs are the same it's not a single cylinder problem something is telling the computer to pull out too much fuel. Start by pulling the codes and then fix any problem that you find, once that is done or if it comes back all clear(code 11 or 111) change the O2 sensor. If that makes no difference start checking for vacuum or exhaust leaks near the motor, there cannot be any leaks in the exhaust or air injection system upstream of the O2 sensor or a lean condition will develop.

 

I would have to say this sounds like a bad fuel pump or clogged fuel filter.

 

Are you loosing coolant?