2.3 pinging/knock/detonation

[brother rat]

My 94 2.3 at 175k recently started pinging on acceleration. Never had a problem with it before, and now it's constantly pinging on acceleration.
I saw some mention of this in other threads as being common to the 2.3
I was just wondering who else has the same issue? Just how common is it?
Any good solutions?
I put in some injector cleaner in the last couple of tanks and have been filling with 89 octane. It seems to have helped, but not eliminated the issue.

 

[RonD]

Pinging is pre-detonation, fuel/air in a cylinder is self igniting just before the spark plug fires, the sound you hear, the ping or knock, is when the self ignited explosion wavefront and the spark ignited explosion wavefront hit each other inside the cylinder.

Pinging happens when the temperature inside a cylinder goes above the octane rating of the fuel being used, this is why using a higher octane fuel can reduce pinging.
Octane is a heat rating, lower octane number self ignites at a lower temperature.

Pinging raises cylinder temps so is self perpetuating once it starts.

Lean fuel/air mix will raise cylinder temps, so can start the pinging cycle, this can be caused by a vacuum leak(leans out mix) or a failing O2 sensor, telling computer exhaust is too rich when it isn't.
Even dirty MAF sensor or cracked intake air hose can cause lean mix.

Partially clogged EGR system, if you have one, can reduce the cylinder cooling so you will get pinging as a result.

Spark timing being too far advanced can start pinging cycle, but you should have the Ford DIS system so no way to adjust spark timing manually.

Yes, good idea with the injector cleaner, dirty injector nozzles drip fuel instead of spraying fuel, so you end up with a leaner mix.

 

[Road Angels]

Check and clean your EGR system, mine has pinged for the last 100k I put 92 octane in her witch stopped it. But mine pings from to much carbon build up in the engine, 300k plus

 

[scotts90ranger]

Get a can of MAF cleaner and clean the mass airflow sensor, that'll probably take care of the issue as a dirty MAF will lean out the mixture...

 

[simpler=better]

If cleaning the sensors doesn't work, it's easy to pull the injectors and clean them yourself with test leads, a 9v battery, and some carb cleaner. There are a few tutorials on youtube.

 

[brother rat]

I still haven't resolved the issue. I cleaned the MAF, no change. I've still been using 89 octane to reduce the pinging.
Would it help to put in 17lb injectors? I've read that the stock 14lb are marginal.
It also sometimes stumbles at idle. And it stumbles/dies when I step on the accelerator from idle (like taking off from a stop sign).
Is there a good way to clean the TPS? Or just replace it?

 

[RonD]

Test the TPS, it is easy.

Center wire is the voltage return wire on the TPS.
Use a sewing pin to pierce this wire.
Set volt meter for DC Volts
Connect volt meter Red to pin
Connect volt meter Black to Ground

Turn on key
You should read .7 to .9volts with throttle plate closed
Slowly open throttle, voltage should start to go up steadily, no jumps or drops.
When throttle is fully open you should see 4.5 to 4.9volts

Slowly close, watching voltage, you are looking for sudden changes up or down, if it is steady then TPS is OK.

14lb injectors are fine.
Check your fuel pressure, '94 should show 30-40psi, running then with engine off it should hold pressure no lower than 20psi.

What do the spark plug tips look like, are they clean or blackish?
You could actually have a rich condition which has built up carbon in the cylinders, this retains heat causing pinging and it also increases compression which causes ping, so a double whammy.