were right in the middle of moving and my truck is down. its a 97 4.6 4wd
i did a tune up, headers and tuned it via our sniper tuner.
shifty was drivn it to our new house and when it went to hit od it stumbled.
i pulled plugs and the number one was litteraly melted. so i did plugs and wires. i had very low fuel press so i figured it was the pump. i put in a new pump sock and filter. no help at all. i pulled the regulator and it was packed so i cleaned it and then decided it was better to get a new one. then i found i had a melted o2 sensor wires. i pulled it and redid it and taped it all up once again no diff.

shifty came by and we swapped the coil packed from his and it made it worse to a point.
well i pulled all connectors everywhere and cleaned hopeing that i had corrosion but no diff.

so now im stuck i have a truck that wont hardly move and has 0 codes at all. my buddy put it on his scanner( he owns a trans shop its like a 4000 dollar scanner) he looked at misfires and 1,3 were missing and 5 was intermittent.

im wondering if i need to do 02s and maby brand new coils??? im tired of screwing with it and am about out of money to put into it.

 

You have a 4six in a 97 Explorer ? It says Expo, top right corner.

What type of plugs you runing ?

Either your running the wrong plugs or you have internal problems. A plug must operate hot enough to stay clean (i.e., not foul) and cold enough to prevent pre-ignition (premature ignition of the fuel-air mixture).

If pre-ignition were not controlled, engine performance would drop and the plug would eventually destroy itself by overheating, thus melting.

 

Sounds like the entire motor is overheating.

Maybe running too lean after the header swap, combined with an agressive tune with too much spark advance.

You could try a 'safe' tune and possibly colder plugs, but you might have bigger problems now.

 

Yea, the only plugs I've seen actually melt is the Bosch sets. The bad in that is they break apart and damage the seat or chip a valve. Loss of compression follow and of course, No Fire.

 

sorry f150 97 with motorcraft finewire platinums. i tried going back to stock and no diff in performance. over 3grand the truck runs fine. under it almost feels like its loading up and it smells rich. like it wont burn the fuel

 

Now it sounds like the EGR valve is hanging open. Try hitting it a few times to close it. Other than that, you'll have to by-pass it to determine. Or, do you have a spare ?

I don't why the plug melted other than your piping in way to much combustion gases. HOT gases.

 

i have it deleted with the sniper as well as the rear cats and o2s i have a autometer temp gauge and the truck has not been overheating at all.

 

Your fuel/air ratios are way out of whack.

 

Bingo.

Last time I checked Shifty still hadn't invested in a wideband to use with Sniper.

It really is an essential part of any tuning adjustments.

Do you have a stock tune you could load?

MGD

 

i never adjusted the fuel settings either.

 

Ok - gotcha - but a wideband would still tell you if your a/f's are copacetic or not, as an aid to finding the root cause.

Melting plugs are one sign of a lean condition - the question is how lean.

Good luck

MGD

 

well the data log will also moniter that and i had planned to run it. i am wondering if the lean condition was a sympton of the pump crapping out. thats when all this seemed to start.

 

sounds like an improper tune...

 

sounds like 30lbs of compression.
number 2 was about 150 i think i have found the problem.

 

Melted plugs typically means that your combustion chamber temperatures are too high. This is usually caused by a lean condition.

Melted O2 sensor wires is usually caused by them rubbing against the exhaust iron. If they were not touching the manifold or pipes, this can also be caused by the exhaust temperature being crazy high, and the excess heat slowly wicking up the sensor wire.

It **is** possible for your engine to be running too lean/hot, and for the truck to NOT overheat or even show a dramatic change on the temp gauge.

If you are now saying that you found a dead cylinder (30lb) next to a good one (150lb), I would guess that your lean condition caused one of your plugs to melt which damaged a valve...