Engine Pinging on Part Throttle

hytorksc

Registered User
It's not really bad, but I'd like to know what are the typical major things that would cause part throttle pinging (hard acceleration, but not WOT) on a 112k mile SC using 93 octane gas?

I tried pulling the octane plug which eliminated it but I lose some low end power and worse gas mileage.

I do have mostly mild bolt on upgrades (no magnum powers stuff) and the engine runs perfect otherwise.

Anyone please? thanks-
 
This could be WAY OFF..But....

I don;t know your fueling habbits...If you go to the same place for the most part or what...But you may have a bad slug of fuel...I would add some power service to it...POWER SERVICE is a Diesel treatment...I have used it in the winter to ensure I don't get water or other contaminants...Also I would add some octane boost if that did not work...If either one of them take care of the problem I would rethink where you are fueling...

There may be a more technical solution to your problem, but this could be something you wanna try...

lata
 
Check Your KNOCK Sensor!

The knock sensor, located just above the starter, may be the problem. It adjusts engine timing based on the amount of detonation it senses. Basically, if you use bad gas, it will retard the timing. If you use good gas, it will advance the timing to the proper amount. If it fails, I suspect the result is what you are seeing. If you try to check it with a multimeter forget it. It will read open. It is a piezoelectric device that generates a signal when stimulated by engine knock. If the knock sensor is bad, you should be getting a knock sensor fault engine code.

Hope this helps!

Ed Springer

edspringer1@aol.com

90 Black Super Cougar 5-Speed
94 Red SC Auto
 
I gotta Q' Ed...

When I first got my SC, I had to try some cheap fuel in it...I was in the service and saw a place I could maybe save a little...Anyway, sure enough the car knocked while pulling a hill..I assumed that was the "Knock Sensor"...No?

Hence sensing that there was not enough octane in my fuel...???

Am I way off?

Is it not suppose to Knock???
 
93 octane is just about the best you will find in most places, so I think your safe there. Octane boost wouldn't be a bad idea. If you add octane boost and the pinging goes a way or lessins then you might try changing the plugs.
At this point and time (with the car JUST pinging) I would change the plugs to Auto lights double platiums. This is a good replacement plug for our cars. They are about 6-8.00 dollars a plug but will worth it. Just make sure you gap the plugs correctly. While your at it you might as well replace the wires also.

Kurt Sr
 
Another possibility...

A part-throttle ping indicates a clogged/partially clogged or faulty EGR valve or EGR tube . You can try a de-carbonizer like RXP or go to a shop and have them run C-foam through it to decarbonize the upper intake and piston tops , as well as the EGR. I'd change the oil after you do it if you do it.

Some SC's don't have EGR though so if you don't it could still be combustion chamber deposits. A friend who is an ASE master tech told me it dosen't take much to cause this. Good luck.

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Thanks!

This is what i needed! Thanks to all who responded. This info. gives me something to work with, hopefully it's one of the problems mentioned. This forum is the best!

Randy-
 
A few things can cause that part throttle pinging.

Broken vaccuum lines can be the related to pinging to some extent but you would get unevenness at idle and
Partially clogged injectors can cause some pinging. Flow rate and spray pattern irregularities can lead to leaning in individual cyl's. This goes back to replacing the fuel filter every so often to keep those impurites out. Berryman's or Redline Fuel injector cleaner might do the trick here on the cheap. Replacing the injectors with a set of flow tested and balanced inj"s would probably give you back lost ponies for about $150.

EGR is another culprit. A valve that doesn't open all the way or at all can cause varying degrees of detonation. If you have over 100k on the motor do yourself a favor and replace it.

Combustion chamber/intake valve carbon build-up for sure can cause that part throttle ping. Some gasoline additive or repair shop decarbonizing should do it.

If you have pinging at part throttle but not at WOT then try some racing gas(a few gallons per tankful should work, Unocal 76 makes 100 octane that sells here in Southern Cal at the pump for 4.00/gal). Also a code reader or scanner would be helpful in diagnosis of the problem. If your getting a code 31,32 or 33 then your egr is in question.

O2 sensors wear out to a point that they switch a bit too slow and can't compensate for throttle changes which can cause pinging.

Clean your MAF sensor element if you have not done so with residue free electronic component cleaning spray to eliminate any false readings to the cpu that might cause a lean fuel response hence ping. Good luck and sound off when solved your problem.



residue free residue free
 
when it comes to the egr you may also want to check out the pressure feedback sensor and egr vaccum control selinoid,as these are just as important as the valve itself because they tell it when and how much to move.
good luck
joe
 
question

My '92 SC does not have an egr, not getting any codes, but i did add octane boost, lucas additive to clean carbon deposits and none of these worked. I'm now looking at the spark plugs as the culprit. I don't think it's the gas i'm using either (93 octane).

I had the plugs in now for a year (motorcraft platnums) and they run very smoothly. i'm thinking that they need to be a couple of heat ranges lower maybe.

I really don't want to pull the octane plug because the car is so fast now, but i know i can't keep running it with detonation problems (it's not real bad but you can hear it when running hard with the windows closed). can plugs and a couple of oily wires cause pinging and detonation mostly during hard acceleration?
 
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1 question I have is are you losing water? Are refilling the resevoir often? What I'm getting at would be the HG's are compromised to a point that you have a split between cylinders at the HG or a cracked head. This is the worst case senario. You wont be losing all that much water either. Solutions?

Go find a station or a shop that sells really high octane gas. 3 or 4 gallons in the tank should do it. Gas it hard through the gears Is it still pinging? If yes is the answer...
Get a leak down/ compression/ cyl-power balance test on all cyl's.
If no...
Reseal all intercooler pipe joints and do a fuel pressure test.

My backyard,in the alleyway mechanics opinion. Good luck.
P.S. Unless you know the guy or trust them intensely stay away from the FORD DEALER. SC's are a ?mark to them. To many avenues to check and too inaccessible an engine bay to check. Find a small shop with an old man or a few guys to talk to. Or do it yourself if you can. Good luck.
 
Uh oh....

I need to chime in here...If you have a kock/ping, I hope you are not mistaking a pink for a KNOCK...This is a mistake that I made..My ping went to a KNOCK and it turned out to be a rod bearing...I would have never guessed that ince it was a fresh eng. at 8K miles....Well now it is a down eng. with 8K miles on it...I tried everything to get rid of what I thought was a ping coming from the knock sensor...Well obviously I was WRONG in a big way, along with several mechanics that listened to it and agreed with me that I was on the right path to fixing it...I hope it is not your problem, but you never know, and I would hate the same thing to happen to that happend to me...Good luck with the fix...You have quite a bit to go on...

Cheers
 
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