Hey Guys,

So i recently got a 2000 4runner with a gen 2 supercharger. It has 280k on it and runs really great except for one worrying problem- with any amount of throttle, i start getting very bad ping. It sounds like marbles in a metal can. It tends to be HG/LRPM but it happens in low gears as well. Any amount of significant throttle causes it.

Here is what is strange- the problem is intermittent and happens after some fuel ups but is reduced or even completely eliminated after other fuel ups. Even going to the same gas station...sometimes its fine...while other times its not.... Gas in the bay area seems to really bring it on...while gas in san diego is more intermittent...

It's also not connected to warmer or colder weather...

Here is what i've done in hopes of tackling it-

All new sparks (the two step cooler ones) and spark wires
New oem fuel filter
New air filter
7th injector kit w/ wahlbro fuel pump
Cleaned out MAF and throttle body

What's next on the list is injector cleaning and installing an AFR gauge...

Any ideas on what could be causing this?

Thanks!

Are you running 91 octane or better?

Yep....always run 91...

How old are the cats? Might be restricted.

283k miles old lol


Any way i can test? No error codes at all

Cats seem to be clogging up as of late.

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Double check for vacuum leak, there's some good youtube videos out there on how to find them using carb cleaner or unlit propane on a cold engine. A vacuum leak will play havoc on the fuel trims.

Clogged cat is possible, I bought a 4Runner of a guy once that the cat clogged up so bad it was glowing red and then the engine blew due to excessive heat. Ping is caused by predetonation in the cylinders after the fuel mixture is added. It can happen with too much boost/compression and too much heat as compressing air creates heat and so would an exhaust blockage.

Worst case scenario, you have a ping happy engine. I have heard of them but never seen one myself. Basically it pings all the time no matter what and can't really be fixed. I don't think yours is but it is always a very slim possibility. URD has mentioned these engines exist but no one knows the cause.

So it's pinging even say from 4k rpm to maybe 6k?

So the engine has 283k on it right now...i got it at 275k. It used to be at 5-6k elevation before...so that probably inhibited the pinging...until i bought it and brought it down to sea level....

I"m still trying to pinpoint when it pings. There are some gas fillups where it doesn't ping at all....but then i'll do another fillup (sometimes same gas station as before but weeks later) and i get pinging under load... It's possible its just an intermittent issue that seems related to gas but really isn't...because i don't think gas blends would be that diff

I'm going to send in the injectors for a cleaning and also take a look at the cat system. I'll also do a thorough vac leak test....prob use brake cleaner/maf for that...

I'll report back on what i find...

Using a non flammable brake cleaner it the best route. It will want to stall the engine.

When I do this test I pull the IAC connector so the ECU can’t respond to rpm dips. It makes it easier to detect.

What heat range plugs are you using?

Are the plugs burning evenly? Do you have a lot of oil plowing into the intake from the PCV system?

When you hear it what is your LTFT?


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How many psi are you running? You could try getting an OBD scanner which shows realtime timing. When it is pinging badly, the ecu is probably pulling timing way down to 9 or 13 etc. I tried alot of options and after 12k miles trying to work around it, ended up cracking the head beyond repair. Still ran but roughly. I ended up putting in a new engine w/ haltech 1500 w/ meth and haven't looked back. I had an extra injector and split second but was never able to get it running just right.

What timing numbers should i be looking for?

Oh yes totally forgot about spark plugs. That could be it for sure. If he's got old worn down copper plugs that engine is going to run poorly.

So....i'm running down clues....Been looking at timing...coolant temps...

I just did a 500 mile trip from the bay area back to socal....one thing which concerned me was my coolant tempts. ECT on my obd was showing from 213 all the way to 221 Fahrenheit. The only time temps dipped to low 200s was when i turned off overdrive going up some big hills

This is almost all highway driving going 70-75-80 on the I-5 (mostly flat incline). Temps were from 92 all the way down to 70.

Radiator and fluid are new.....water pump was changed 25k ago by previous owner. No idea on the thermostat.

What gives? Is this normal on a supercharged rig? Or are temps way too high?

And could this be causing the intermittent ping under boost?

You should roll in a new thermostat to rule out issues. If I recall correctly, I think there's even a different thermostat that I suggested to be used for the supercharger application. The orientation matters. It's about 5 minute job.

Also, how does the condenser look? If it's beat up, that will impede airflow to the radiator.