I very much appreciate your patience. I'm more than a little theatrical at times, but this issue, which isn't the end-all of problems, does have me at wit's end.

I'd really like to keep the truck, mainly because I can't afford to pick up a 400 dollar a month payment right now. I'm gonna do one more thing before resorting to putting harsh chemicals in my intake manifold - change the coolant. It's entirely possible that my radiator fluid is kaput, it's at that stage where it's beginning to turn brownish. I'd avoided changing it until now because I had every intention of changing it with the oil, but I was gonna change the oil after doing the Seafoam thingy. I'm normally not the kind of person who believes that putting crap in the engine does anything except mask a problem, but I have heard good things about de-carboning the engine.

As I need to see, I'm gonna have the coolant flushed today with the oil. I can change the oil again when/IF I do the de-carboning.

The problem only really surfaces when the engine is hot. It doesn't seem to ping when the engine is cool or cold. Originally I thought that was because the fuel was richer with the choke on (assuming FI vehicles have chokes) then got leaned out too much once the choke was off.

 

Well you've given up some more good clues imo.

The fact it doesn't ping when cold & in the "closed loop", caned programmed mode, in which the fuel mixture is richer, is maybe, another finger pointing at a fuel trim problem. BUT with your statement about the condition of your coolant, you might have a cooling system thats so corroded up, that it's not pulling the heat out of the head quickly enough, when the engine is warmed up.

Will be interesting to hear if cleaning up the cooling system, affects the ping problem.

Also a good idea to get the truck up to date on all past & present, due scheduled maintenance. You know something as simple as a acting out PCV valve can lean out the A/F mixture & I'll bet it's due for changing, with the mileage you have on this ride.

Have you had the computer scanned for set, or pending codes???? Maybe it could offer up a god clue or two, to help point your troubleshoot in the right direction.

 

Unfortunately the saga of the pinging 3.0 is splayed all over this forum, sorry for the mess guys....

Anyway, yes the PCV valve is brand new. I'm about this close to getting a much better code reader, especially if I'm gonna keep this rig and maybe start modding it. My code reader doesn't pull pendings, but it isn't reporting any problems with any systems, it tested the O2 sensors fine. Perhaps a better code reader would do me a big favor, I'll have to see. I might even go get one if changing out the coolant DOESN'T fix the problem - because at that stage I'm pretty much out of ideas here.

There is just something in me that doesn't want to take it to the stealership, mainly because my local one is Sound Ford and I don't trust them (maybe I'm being uncharitable though).

 

Bump cuz I want to know what happend here. Results?

Question: Do these Ranger engines use an EGR system? Symptoms sound like it could be EGR (if one is present....).


CMOS

 

Eigenvector

I'm new to the forum but check this out. Seems to me from past research and experience that most EFI systems incorporate an anti-knock sensor that the computer uses to determine max timing advance. Early units require the mechanic to set the timing mark on the harmonic balancer to what the computer expected. Now they use a Crankshaft Position Sensor on the balancer to tell the computer where TDC is, the computer thus taking it from there.
The computer would advance the timing until pinging is just starting(which is below what you or I could hear but sensed by the anti-knock sensor) and then back it off a predetermined ammount for optimal power/fuel performance.

Does yours have one, and has it gone 'deaf'? The crankshaft position sensors are pretty rugged and reliable( it's not a variable signal type sensor - it's either on or off)

Just an idea
fred