A friend has a '92 F250 with a 460, it runs fine until it downshifts and turns a few RPM while towing an enclosed trailer then it starts pinging. He had the decarboning treatment done (at Valvoline) but it still pings (he is using 92 octane gas). Any ideas??? Is this beast supposed to use 92 or is it set up for 87?

TIA

JohnF

 

I have a 97 f-350 with a 460 and an automatic, it also pings under load and when towing, what i did was take the air cleaner assembly completly out, i left the hoses coming off the mass air and just shortened them, a short peice of 2 1/4 pvc pipe fits into the hoses and a fram filter (ca 8805) fit onto the end of the pvc pipe, i took the hose off of the vent on the valve cover and put the filter from the air box right on the valve cover with a short piece of hose, i also put the same filter setup on the base of the mass air where it originally went up into the plastic assembly that connects with the air hoses, i gained about 2 miles per gallon with just this change, and it also sounds really cool. I don't know if your 92 is set up the same, you may not have the setup at the base of the mass air but everything else may be the same, it didn't ping hardly at all after that, i also make my own octane booster and that really helps. hope this helps you

outlawdady

 

John, what is your base timing set at? Remember to check it with the SPOUT removed. Factory says 10 BTDC for my '88. My Mustang pings under heavy load on regular gas when I advance it more than 12-13 degrees.

 

I don't recall if we checked his base timing, there are at least 6 Ford PU's of different years and setups in the group and I can't remember what we did or checked on who's. I'll take a look tonight if he comes over.

JohnF

 

Base timing was about 8deg, he set it to 10 and it pinged like a momma. Set it down to 6 but it still pings uphill at any decent RPM. So, sounds like leaning out. Whatcha think ???????

JohnF

 

How old is your 02 sensor? My 1989 F-150 302 pinged while pulling my boat or snowmobile trialer. I changed the O2 sensor last spring and it does not ping at all. The voltage output flattens out over time so they don't give a good reading to the ECM to compute proper fuel metering.

 

I've been reading the conversation on this subject and was wondering where I would find the O2 sensor on an '89 460? Any help would be appreciated.

Bill

 

>I've been reading the conversation on this subject and was
>wondering where I would find the O2 sensor on an '89 460?
>Any help would be appreciated.

Just follow the exhaust down from the exhaust manifold, it the only thing in the pipe with wires hooked up to it, its down about a foot or so.

 

Just a comment for reference...

My 94 F250 super cab long bed with 460, 4x4, E4Od and 4:10 gears runs well on regular (87?). If I tow, I can run with regular but will ping on hills or in hot weather. To eliminate the ping I can use either the middle grade(89?), or usually I have one tank with super 92 and the other with regular and switch tanks while driving.

It works for me. If 92 doesn't fix things for you then like the rest of the postings say, there is probably something wrong.

Good Luck,

Jim Henderson

 

Pulled codes and nothing shows up. I hate to start just replacing things (that's the way the Ford garage does it...at $55.00 hr plus parts). Any more ideas??


JohnF

 

John,

Did you replace the O2 sensor? That was my thought, other than running an incredibly bad batch of gas. How many miles are on it? Engine and sensor? Has the sensor ever been killed by running leaded gas? (Seen this once from a neighbor who had his vehicles outside the country stationed overseas). I don't have the manual in front of me, but I'm sure you could connect a voltmeter up to the sensor and check the voltages when the engine is at normal operating temp to see if the sensor is providing a signal within voltage range before you go out and purchase a new one. I don't know if an out of range voltage signal would always cause the EEC to spit out a code. Maybe, maybe not.

I run 87 octane in my truck with base timing set at 10. Thermostat is 195, and it has never pinged, even when pulling 8500 lbs in hot humid weather with AC on.

You did pull the plug on the spout and put it in your pocket when you checked the timing? I would guess that if you are indeed running at 8, you probably don't have much more distributor adjustment left. Its been a while, but I don't think my truck would have much room for adjustment under 8-10.

But lets go back to you initial description. You said it runs fine until it downshifts and turns a few rpm when towing a trailer, then starts pinging. I'm assuming it never pings when under a load and spinning happily at a steady state, but only pings when it "downshifts" and accelerating? Was that a manual downshift, or a step-on-the-gas pedal transmission kickdown? It is an automatic, right?

Is it a computer controlled automatic-overdrive transmission? Connected to the EEC? If so, I wouldn't think a bad connection to the EEC could cause an ignition timing change, but I could be wrong. Bear with me since my transmission is an old fashioned C6, pretty much as basic as an automatic can get.

SWAG#2: Have you ever just disconnected the battery and erase any previous EEC settings that may have been caused by bad gas?

What color are the sparkplugs after a "pinging" run? Brown, black or bright white? Are the plugs the correct temp? What plugs are in it?

Any other temp sensors disconnected on the engine? Or reading incorrectly?

TPS between 1 and 5 volts from idle to WOT?

I hate Easter Egging it (buying parts) needlessly as well.

Hope this helps.

 

Try replacing the fuel filter I have a 1990 f-350 460efi and I replace mine yearly. When they get plugged they can cause a lean condition and no codes.good luck

 

What is the SPOUT you refer to when checking the timing?

 

I had a similar problem with my Ford Van. I read on this site a fix that helped me. That was to replace the MAP sensor. It fixed my problem and I think it is a very common failure with Ford trucks.

Andy

 

To check the timing of TFI-IV ignition systems on EEC-IVs, you need to unplug the single wire SPOUT (Spark Output). This is a small plug/fitting that is connected to the distributor via a small pigtail wire bundle (at least they are on my truck and Mustang). I think it's a couple of wires and they are only a couple of inches long. You can find mine next to the distributor(s). Pull the plug out of its fitting to be able to take accurate readings.

Remember to replace the SPOUT when finished. If you don't, you probably will when you pull out of the driveway.

Hope this helps.