Help with pinging
 

My '94 22re pings around 3500-4000 rpm. I have a TRD level 1 cam, Pacesetter header, Jacobs ignition, AFM mod(3 teeth rich), 2 1/4 exhaust, 3" intake tube from AFM to throttle body,ECT mod, 4 degrees of ignition timing (5 degrees seemed worse). Clears up past 4000 rpm. I think I have covered it all. Was wondering if grounding the shield on the knock sensor would help? Any help would be appreciated.

what octane gas are you running? with engine mods, you need to run higher octane gas... should be running 91 or 92 octane

Been running 89. I will try the higher octane. Can't remember how it responded with 92 Octane. I'll try it and see. Gas prices are killer, would love to keep it on 89.

if its pinging htere isnt too much you can do if it requires better fuel..... 87 is cheaper and im sure running that in your modded truck would be very bad for it...

Thanks. I'll fill up with 92 and repost.

With all those mods you NEED to be running 93 octane.
Cap'n

Other possible causes of pinging is too lean of a mixture, such as vacuum leaks, faulty o2 sensor ect. Excess carbon build-up on the pistons and head causes pinging. A seafoam treatment through the pcv should cure that. Sparkplugs with too high heat range may also cause pinging. You may want to try a colder plug.

try to retard the timing a couple degrees, and are you checking the timing with the check connector jumped TE1 E1 teminals

Yes, I'm checking my timing properly, the O2 sensor has been replaced and Seafoam is used regularly. I dumped a bottle of Lucas octane booster in yesterday and topped off the tank with 5 gal. of 93 and the ping is gone. I should have known. I raced motorcycles for some time and 110 octane was all I could run without ping. Thanks guys for using common sense when mine failed me.

ive bought some octane booster too...(stp) the bottle says to pour on top of full tank..will that yield the best results? i have been running 93 for my s/c 4runner and still have the ping...hopefully this might help

Someone mentioned that you need to be running higher octane with the mods that you have. I disagree. You are still N/A at stock compression ratio. You *are* flowing much more air through the engine, which means you would run way lean. So then I see that your AFM is adjusted 3 teeth rich. How do you know if this is the proper adjustment? How do you know if that is rich enough? Have you tested your Air/Fuel ratio with a wideband O2 sensor on a dyno?

I think what you have effectively done, with your 93 octane fuel and octane boosters, is applied band-aids to your real problem- A/F ratio. I see that you have retarded your timing also. I don't know about you, but most people that have tuned a healthy N/A engine make efforts to keep the timing at least stock, and often times advance it. If I had your motor, I would expect to still be able to run 87 octane, at a few degrees advanced from stock, and never have pinging.

Get your truck on a dyno and tune the A/F and keep running 87 or at least 89 octane. Your motor will probably last longer if you do.

I agree, if you are still running the stock compression ratio then you shouldnt need a higher grade fuel. Unless for some reason you are running hotter plugs...

sounds like it could be carbon buildup. exhaust and ignition aren't going to make you ping, unless you're running too hot of a plug(as noted above) and it's pre-igniting the mixture. carbon on the pistons or in the head will raise the compression ratio. try running some seafoam through a vacuum line and see if you notice any differences.

with my ignition(accel coil and plugs gapped to .045) it wouldn't ping unless i loaded it up big time -- running 15* of advance. it's almost impossible to make it ping with the factory 8* setting for me, but i'm also running an open chamber head with a lower compression ratio.