Hey 4bang,

Sorry to bump an old post, but did you ever find the fix to your problem?

I have been having almost the exact same issues and have done pretty much everything you had mentioned above - besides changing my injectors. When I came across this thread it surprised me because I have been down the same road!

Just curious if you found a fix? I’m currently looking at re-checking my balancer, checking my distributor or replacing the AFM.

 

I wouldn't say I really found a great fix but I'm satisfied enough to stop hunting for now. I still run 91 octane all the time. My mechanic who works on a lot of the older toyotas / land cruisers in San Diego recommended this based off the reasoning that California gas with ethanol is somehow a culprit (not sure I buy this but I don't know better). From my last post I've installed a new pre-cat 02 sensor, checked compression (all within normal range and less than 10% difference from eachother), and rechecked a bunch of the stuff on the list (all came back normal). I hardly pre-detonate and if I do it is usually only momentarily on a big hill on a hot day. I honestly think part of the reason my situation has improved is that I drive further for work now. Previously I only lived like a mile from work and I would only go on longer drives occassionally. This is subjective but it has seemed to helped with the detonation. I think a part of my pre-detonation is from having 4.10 gears and 31" tires in a hilly area. The 4.88's I junked didn't end up working out and my shop quoted me $3500 for the re-gear (no thanks!) so I haven't been able to test this yet. If you want to list everything you've done, I can take a look and offer any suggestions that might pop in my head.

 

Thanks for the detailed write-up and the reply, It's great to get some info from someone who is experiencing the same phantom problems.

My 4Runner is a '94 5-speed with 297k. I bought it with 263k. Had the cylinder head replaced about 25k ago. In March, I got back to California after a trip all way from Northern CA to Key West FL and back.
The car did great. The only thing i had to replace on the road was clutch master and slave cylinders and sway bar bushings. Other than that, the car had almost no issues!

Since I got back to California and back to work, the weather started to heat up and I began to notice the pinging when the engine is under load and the ambient temp is about 80F or greater. It has gotten progressively worse over the last 4 months, but seems intermittent. No check engine light since I have owned the car. I have always run 91 octane since I have owned the car.

Two months ago I started to replace a ton of parts, mainly to do some maintenance before it hits 300k, but also in hopes of fixing the pinging along the way. No such luck.

Heres what I have replaced or done so far.

Almost al the parts listed are Toyota or OEM parts from the dealership or quality online parts stores.

- Plugs, Cap, Rotor, Wires
- Vacuum Lines, PCV valve, Air Filter, AC Idle-Up Switch
- Fuel Filter
- Adjust Valves per 22reperformance specs, replaced valve cover gasket - checked the timing chain guides by looking down the front of the engine and they appear to be the metal guides in-tact
- Replaced and set TPS
- Idle air control valve
- Completely cleaned TB and replaced idle adjust O ring and TB to manifold gasket
- Intake boot elbow - at TB to plenum
- Oil disptick
- Thermostat
- Pre and Post O2 sensors, exhaust manifold gasket, exhaust to pipe gasket
- Tried eliminating the EGR from the system via 22reperformance tip - by blocking it off at the back of the intake manifold.
- Timing - had to back the timing off to about 1-2 degrees to keep the pinging down (timed with jumper wire on the correct terminals)
- I have run 6 - 8 cans of fuel and carbon cleaner through the gas tank over the course of 3 months (mostly Gumout with Carbon Clean)
- Tried richening the mixture by adjusting the AFM 2 notches richer, also cleaned the AFM contacts - no change
- Replaced AFM with aftermarket off-brand to see if it made a difference - no change

Overall, the car is running great! It's smooth and sounds fine, but when it gets a little warm outside and it is under load, its pinging like crazy. I was told it could be carbon buildup in the cylinders, and this may be the case. I bought a borescope and took some photos inside the cylinders. The pistons do have a lot of carbon buildup on them, but not what I would thing would be extreme. Also, the head only has about 25k on it and seems to have very little carbon.

I have not done a complete carbon clean on the system yet either with water or with sea-foam spray or some cleaner through a vacuum tube - this may be my next move.


Things I still may check:

Injectors
Ground cables - battery, engine, ECU
Harmonic balancer/damper (however engine feels smooth and I did check for TDC at timing mark and appears correct)
Battery cables
Igniter/coil
Fuel Pump/Regulator
Knock Sensor
Alternator/regulator

Well, if you made it this far, thanks for reading. The pinging situation is extremely frustrating after all this work.

Any suggestions would be greatly appreciated.

THANKS

 

I may be mistaken, I usually am, but nowhere did I see that you replaced the fuel filter. After nearly 300K miles, it's absolutely time. It's a PITA on these trucks, but an essential bit of maintenance. If your mechanic thinks that running 91 octane is a possible fix, I would think that maybe a new filter could improve things too. Why? Because if it's clogged, the truck may be running lean when it needs the extra fuel for a steep hill on a hot day. With you running th fuel system cleaners through the truck as much as you have been, could a lot of the crud from the tank be running up and into the filter? After 300,000 miles (nearly), there may well be a lot of crud indeed.

I am NOT a mechanic by any stretch. I'm a Radar tech, but I had an 87 4Runner for a long time. That's my only claim to knowledge about them. I replaced the fuel filter on mine once, in 275,000 miles, and when I did, it really needed it.

Onward, to the harmonic balancer: make sure the two halfs of it can't move in relation to each other. There's a thick rubber piece between the two parts, and when it gets old and brittle, it can allow the two parts to slip one way or another. That, obviously, can throw the timing off. Timing in error, pinging to follow.

My last idea: is your knock sensor OEM? I had to replace the ones on my 99, and the first ones that went in were aftermarket. Supposedly equivalent to OEM, but they threw the code for the knock sensors. Brand new, fresh from NAPA. Went to a local dealership, bought 2 new OEM sensors, and the pigtail for them, codes gone. Just a thought...

Just so you know, there are 4 grounds that matter the most in the engine compartment. The one you should be most concerned with is the one from the head to the firewall. It goes from one of the bolts on the driver's side lift hook to the firewall directly behind the engine. Just about where the 1/2 moon portion of the valve cover gasket is, if you were to go directly from that to the firewall. Make sure both ends are clean and shiney, bare metal at both ends. Same with the ground cable between the battery and the fender well. It goes from the battery directly to the fender's metal just in front of the battery, behind the headlight.The other ground hooked directly to the battery goes down to the engine block, normally connected to the AC compressor mounting bracket. Again, make sure both ends are clean and shiney. No oil or dirt buildup, no corrosion, nothing but bare metal touching bare metal. It matters. Give the battery terminals a good cleaning while you're at it.

Good luck, and I hope you get this figured out.
Pat☺

 

So I've pretty much done everything you did but I also removed the head and manually removed all the carbon from the piston crowns. This was a HUGE pain in the ass because your head bolts are likely seized onto the rocker assembly with carbon and you will have to get your head resurfaced by a machine shop as well as clean your block mating surface extensively. I wouldn't suggest this unless you absolutely had no other options and the pinging was driving you that crazy. That being said this made the most immediate difference for me. After I finished this I didn't get any pinging for about 6 months or so. I also used a scope to check the carbon condition before the teardown and about 6 months after the teardown. The carbon came back and I got a little bit of pinging again (don't know if this is the culprit for sure). Seafoam didn't make a difference for me but you should definitely try it. I think I used a syringe and pushed it into on of the vacuum lines by the front of the throttle body.

A couple things based off what I read that you could try:

Vacuum test the system starting at the intake manifold (either DIY or professionally) to make sure that no other gaskets are drawing in air post-AFM. This is more for peace of mind than anything.
Are you seeing a decrease in power from knocking your timing back? Some of these engines are known to perform better (with less pinging) when the timing is knocked back for whatever reason (22reperformance talks about this on their site and there was a Toyota service bulletin supposedly regarding this). If you're not noticing a loss in power, you could continue to try and knock back your timing.
You probably already did this but verify that your timing advances back to ~12 when you remove the jumper and also doesn't get stuck at some high number when you briefly open the throttle and let it return to idle. You said you replace the TPS so probably no mechanical issues but something to check.
You can test your fuel pump with the free rental tool at autozone or o'reilly auto parts if you have one nearby.
You should also verify that your cooling system holds pressure (I want to say 12 PSI?) for like 30 minutes without dropping. Check your radiator cap too. Bleed your cooling system of air if you have never done that.
Get an OEM gas cap if yours isn't OEM.
Test voltages at the ECU (this will verify ECU values as well as sensor values). Honestly this is probably a top to do if you haven't since bad input can cause bad fuel/air calculations by the ECU. You need to backprobe the wiring harness (I used paperclips) and measure voltages / resistance with a voltmerer. The FSM has the the voltages but make sure you find the correct pin-out for your year vehicles since they are slightly differnt.

These are some preliminary ideas. Hope it leads you in a decent direction. I wouldn't pull the head off unless you have another reason to as it was a giant pain in the ass to do by myself.

 

My '89 pickup 22RE 5spd 2wd pinged terrible here in Fresno summers. I was 2nd owner after my brother who bought it new i 1989. He said it always pinged and the shops couldn't figure it out. I had to use premium gas during warm weather.. A few years ago it started running on three cylinders. Bad injector. My mechanic replaced all four injectors with rebuilt injectors. After that, the pinging went away. My theory: wrong injectors from the factory.My anecdote.

 

I assume you put the recommended ND or NGK sparkplugs?

As a generalization, when dealing with engine ping we made sure ignition components were good, then checked timing. Then tried different gas(top tier, higher octane).

Is the bolt at the distributer adjustment fairly centered in the slot, or off to one side? Same with the TPS. Where does the lock screw sit in that slot?

 

Hi everyone,

Thanks for the replies. I'm still working on finding this thing!

Pat, thanks for your detailed reply. I did replace the fuel filter a few thousand miles ago during the same time I did all the other work. I wish i could chalk it up to a bad fuel filter, but its a Toyota one and i trust it. I also changed some sensors around the same time which I forgot to list - the temp sensor for the gauge and the temp sensor for the computer - green connector front of the engine. Both are Toyota.

I have not thoroughly examined the balancer yet, but that is on my list. I would have thought I would feel the engine shake pretty bad if it was out of whack, but maybe its just off by a little bit.
From what I know, the knock sensor is original and OEM - most things on the truck were OEM when I bought it. It has been serviced at Toyota until about 250k miles. I may need to get eyes on the knock sensor to confirm - I have not seen it.

On to the ground points - I did check all ground points and I found some interesting clues there. All the points except one looked good, but I cleaned them up with a stainless steel wire brush and retightened them anyway. The one bad point was a major one - the main negative connection at the battery coming from the AC bracket was really corroded and pitted. It was hiding under a nice clean SS nut and washer, so I almost didn't check it. I ended up cutting the end of that negative cable off as well as the small ground that goes to the inner fender there and crimped on a new copper connector. I will be talking to the dealership soon to see if I can find the original cable and replace the whole thing. I hoped this would make a difference, but the pinging still exists.


4bang,
Yes, that is what I am trying to avoid for the time being - removing the head. I don't have the time or space to do that right now. I am on a work assignment away from home and have been doing some of this diagnosis in auto shop parking lots. Judging by your experience, it does sound like the actual culprit for me may be carbon buildup as well. I am trying to rule out anything else, but my list is getting smaller and smaller. I figure that if it is the carbon buildup, I will more than likely just rebuild the entire engine and any new parts I'm buying now would be nice to put on a newer rebuild anyway.

About the timing, power feels ok. When I was timing the car multiple times it would sound a run better at idle when the timing was advanced a little more, but it would ping like crazy when I left the timing where i thought it was supposed to be. I ended up backing the timing off just to stay away from pinging all the time. I need to carefully check the balancer and confirm it hasnt moved a small amount.
Thanks for the tip on the fuel pump tester. I didnt know that was an option. I'll look into it. Gas cap is OEM, radiator and cap are a little over a year old. I will definitely be looking at the ECU! Thanks for the tip on that.

JJ, certainly could be injector related. I believe they are original. I'm trying to get the truck through until I have time to wait to have mine rebuilt vs buying new ones. Thanks!

Jim, the plugs are NGK. I ordered them from 22reperformance with my other ignition parts. The distributor is sitting close to center on the adjustment. The TPS is a little further off center, but still not by much.


One major thing that I found a while back was a frayed wire at the the igniter. From the igniter to the coil. I didnt think it to be enough to cause any issues before, but I rechecked it again while looking at wiring/grounds and determined it could be much more corroded inside than it looks like. The dealership here quoted me something like $860 for a new igniter, so I ordered a cheap (probably junk) one off of amazon for less than $30. I figured I can use that one to trouble shoot. If it solves the problem, I will look at buying a new factory igniter or using the wiring from the cheap one to repair the original.

Thanks all for taking the time to give me those suggestions. I'll keep updating here if that's alright.

 

You might try adjusting the TPS using the timing light method I've mentioned here before. It's vastly better than the FSM, and one that Toyota techs used bitd. i kinda doubt TPS is the issue, but you should know about this method. I wrote a post here for the 22RE, but it works on the 3VZE(just use 3VZE timing specs).
If you're wondering about your spark here's a cool tester that's dirt cheap.

 

Hey, I have a 95 22RE 4x4 that has had pinging issues for 15 years I’ve owned it. New motor from 22RE performance, cleaned and balanced injectors, you name it, I’ve tested and replaced the entire systems and truck. However, I came across a video on YouTube (No Nonsense Knowhow channel) where the YouTuber Chris has an old Tundra that has pinged for many many years he’s owned it. Moral to the story is, he put an oil catch can on the PCV and that fixed the pinging. So, I tried this on my 22RE, and yes, it fixed the problem almost completely. Mixing oil into gasoline lowers the effective octane rating of gas, just as in 2 cycle does. The vapor from PCV venting mix with the intake air and lower the effective octane rating of the fuel. For a $30 part on Amazon I figured it was worth a try, and it worked. This also should work to prevent carbon buildup on the pistons over time.

Prior to the catch can, I’d had good success fixing ping with using a two step colder spark plug. I tried the Denso W20, but only saw minor improvements. Then, because the W22 or whatever comes next in heat range steps for Denso was a challenge to find, went with an NGK BPR7, instead of a BPR5, and that was where I noticed a significant improvement in pinging.

I’d read about newer Toyotas having pinging issues and that Toyota recommended changing the spark plugs to a colder plug. Now, on long REALLY steep grades, I still had the occasional ping here and there, but I live in WA at the base of snoqualmie pass in the Cascade mountains, so some pinging while full throttle trying to climb these hills is expected. The PCV oil catch can made a big difference. I’m still playing with what spark plugs I want to run, as when installing the catch can, I changed my plugs back to a Denso W16 exru. I may settle on one step colder with the catch to completely eliminate pinging all together. It’s a process. But for now, I believe the catch can is a remedy I can live with. And it will keep the intake plenums and pistons cleaner too.

 

My 22RE has pinged like crazy in the summer since I’ve owned it, so about 100k miles. Nothing ever got it to go away except setting the timing to 0° or running 91 octane fuel.

I remember reading a post a few years ago about someone who found out some of the 22RE motors had this problem and it has to do with the ECU. Base timing may be set at 5° but instead of the advance curve that it’s supposed to have it quickly skyrockets and causes bad pinging under load. His remedy was to put the timing to 0°. So in summer I put it to 0 and deal with the slight loss of power. My motor would ping at any throttle position as long as I was on even a very slight grade. Even at WOT when it’s dumping all the fuel it can. I’ve verified this with a wide band o2 sensor and yeah it still pings the same whether the fuel ratio is 9:1 or 14.7:1.

I too chased my tail for about a year trying to remedy the ping but gave up once retarding my timing worked. I’ll give the oil catch can a try, it does make sense because putting oil vapor back through an engine isn’t good for an engine.

 

The base timing is set to 5° WITH TE1 and E1 in the test jack jumpered, and the engine warmed all the way up. AC and Heater off. Not over heating, but run long enough for the oil, water, and so forth to be at the temperature they would be after, say, a run to the store, and back, 10 blocks away. Something like that. The jumper pretty much removes the ECU, and all it's sensor inputs, from the equation. A paperclip does a fine job as a jumper.

Then, with the jumper removed, and the engine started again (don't pull the jumper with the engine running), the timing should be about 12-15°, maybe a bit more. AT idle. It will jump around some as the ECU makes fine adjustments. Don't adjust this, just check it. Only adjust the timing with the jumper in. The result should be the distributor just about centered in it's adjustment.

Once you pull the jumper, the ECU is controlling the timing, dependant on all the various inputs the ECU gets from the various sensors.

I did my 87 4Runner several times during the period I owned it, and I never had any pinging, running on 87 octane.

Good luck!
Pat☺

 

Pat here is correct about timing, but I’ve also read and tried all the TSB information (also detailed by Jim Putney at 22RE Performance) about retarding timing and the ECU advance issues. This topic has been beaten to absolute pulp on here for many many years. I personally credit all of the issues with pinging to changes in gasoline (ie ethanol etc) and modern fuels. I have a great ethanol free station 1/2 mile from my house and ALL of my older Toyota’s get that gas in them as much as possible, and it does indeed help, and they do seem to run better on the ethanol free gas. I’ve also messed a TON with the octane rating business, and it helps some too.

I wanted to come on here to mention the PCV oil catch can remedy, as it has worked fantastic for my 95 pickup. The catch can I’m using was $17 on Amazon and I ordered a 10 ft length of high pressure (but not necessary) 3/8”/10mm fuel line for $11. So for about $30 and an hour of time (most of which was building a small aluminum bracket to bolt the can to my upper right stud on the brake booster) I’ve stopped the excessive pinging on my truck. As I mentioned above, lower heat range spark plugs also helped out a bunch, but that isn’t something I necessarily liked doing. It worked out though. I tested the can and drove the truck Friday a good 30 miles on the freeway and didn’t notice any pinging, and this was with the recommended Denso W16 exru plugs in. I suspect if I went to one step colder on the plugs and run the catch can that the pinging would be eliminated no matter what gas I’m running.

I’ve always used my multimeter to set the TPS, but I may try this timing light method recommended above. Way way back years ago I had a sloppy throttle linkage and butterfly valve in the original throttle body on my 95, and I spent a lot of time playing with the stop screw, springs in the linkage, idle screw, and TPS trying to remedy the hot start issue, thinking that whole system had something to do with it. I was wrong, and it had more to do with an inoperative idle up circuit via the water temp sensor and (Blue) vsv, but it enabled me to have a great understanding of the TPS, throttle body, and linkage system. So I’m wondering if the timing light method would yield a different result from what I’d get for a proper TPS setting vs the multimeter..