pinging engine 90 toy pickup 22RE

[saturn2003ion]

I have a 1990 Toyota Pickup, 2dr, 22RE, 4speed man, with 150K miles that seems to ping when accelerating, even light acceleration. I have it well tuned, using factory toyota parts. It "pings" less with premium fuel, but still does, so that is what I use. I have replaced the plugs, cap, rotor, and wires, and the standard tune up stuff regularly, oil/filter, air filter. I have also removed and cleaned the throttle body, and intake chamber, adjusted the valve clearances; replaced both front and rear oxygen sensors, the throttle position sensor; about 25K miles ago, I replaced the timing chain/guides/tensioner with the dual row chain/kit by LC Engineering that also included a new water pump and oil pump(I replaced it when I heard the chain slapping noises; I thought this was the source of the pinging noises; the guide was bad, and the chain
started to rubbing the housing) But the "pinging" still occurs. The ignition timing was timed following the service manual's instructions including jumping the service connector as instructed. All the vacuum hoses are in good condition and appears to be correctly connected. It seems to ping less when the engine is cold. The fuel filter has been replaced; and I also replaced the fuel injectors with rebuilt injectors with no remedy. The truck doesn't seem to burn oil, has good power and MPG. It's been pinging for the last ~40K miles. Oh, and it does pass the CA smog test. Any suggestions on what might be causing the pinging? Thanks!

[natenelsen]

did you adjust the valves hot? other than that it sounds like you have taken a good solid approach to solving this noise. How many miles?

Nate

[saturn2003ion]

I have adjusted the valves hot as instructed in the service manual, the truck has 150k miles.

[natenelsen]

I know sounds are hard to describe, especially via text, but does this ping have a "ring"(like a muffled bell) to it or is it more "flat" like a "tick"(like a metronome in time with the engine)?

Nate

[saturn2003ion]

Yes, sounds are difficult to describe, and even locate...can be tricky.

The sound is almost like a clatter sound, only under acceleration, some times even at slight acceleration and cruising at highway speeds. When the engine is still cold, it doesn't ping as much. I've noticed that some cold foggy days, it might ping less.

I believe that the 22RE fuel injection is based on the Bosch L-Jectronic Fuel Injection...which pulses all fuel injectors at the same time, which gives the engine a "ticking" sound, which is normal; the pinging I hear isn't this sound.

Thanks for the interests! Any suggestions?

TS

[93'Toy P/U]

I have a 93' Toy 2 WD P/U that started pinging 4 mo ago. I have adjusted the valves, advanced the timing and then finally did a fuel system clean to remove the carbon build up. I use premium gas and it ran great for 2 weeks. It now pingings again. I have 130,000+ miles on it and all the thingings you did to yours was done to mine. Timing chain, fuel pump, water pump, new A/C compressor last year etc. I have checked the belts, hoses. It has a year old heavy duty radiator. So what have you come up with? You are not alone!

[TurboR6]

You may have carbon built up on your pistons or valves. I would suggest letting the truck warm up, remove the air filter and while the truck is still idleing spraying a fine mist of water into the intake.. "FINE MIST" like with a small spray bottle.. the engine will sputter a bit but the vapor will break loose any carbon buildup..have you checked your fuel rail pressure? does the engine run hot? Or cold for that matter?

[saturn2003ion]

Thanks I'll give the "FINE MIST" a try. Humm, perhaps on foggy days, as I mentioned earlier, this is the reason why the pinging seems less? The engine seems to run "normal" from the typical position of the tempurature gauge. I'll check out the fuel pressure, and replace the pressure regulator if necessary... Thanks!

[tjr1000]

I had this happen with two small trucks after they reached around 100k miles. The problem was carbon build up in the engine. The build up causes increased compression when the engine is hot, thus the pinging sound. In the pre fuel injection truck the problem was easy to fix. A bottle of top engine cleaner poured down the throat of the carb did the trick. It is more complicated with fuel injection because there is no easy way to get solvent into the engine at a high enough concentration to do any good. There are mechanics who have the equipment to do this. I believe PEPBOYS offers the service. It is likely to cost $100 or so. But the increase in performance is worth it. And then you don't have to pay 20 cents a gallon extra for premium fuel.

[saturn2003ion]

Carbon buildup in the engine, that seems to explain the symptoms...I would assume if it is somewhat cleaned up so it appears to run better, however this problem will return in a matter of time. Thanks for the suggestions and answers!

[natenelsen]

premium gas=higher octane=less prone to spark knock. lower temp and high humidity mean cooler air charge temps witch help prevent spark knock. I like this diagnosis, it fits with the condiotions. Good job 93p/u!!

So did this fix the problem?

Nate

[93'Toy P/U]

Originally Posted by natenelsen

premium gas=higher octane=less prone to spark knock. lower temp and high humidity mean cooler air charge temps witch help prevent spark knock. I like this diagnosis, it fits with the condiotions. Good job 93p/u!!

So did this fix the problem?

Nate

The problem is better in cooler temps outside, on the freway but still remains a porblem in stop and go traffic. I have had my mecahnic do a second "Run Rite" fuel system cleanings with minimal minimal results. A slight timimg adjustment as well. I am afraid I am stuck with the pinging problem.

[natenelsen]

I have never heard of run rite, never used it, I have used the snap-on system, BG and Dayton products cleaner. I think the Dayton worked the best especially when used with the snap-on machine. (it plugs into the fuel rail). Avoid the stuff that looks like washer fluid made by a company called QMI? it does not seem to work at all. I have seen a couple of old-timers *slowy* pour a quart of water into the carb of a running engine. Used to tell me it worked about half the time. I do not reccomend you do this unless you understand what a sydroloc will do to a piston rod. If you get this fixed be sure to let us know what it takes.

Best of luck

nate

[Tim81ta]

This might help. I read the postings, you might want to invest a few dollars in a automotive stethoscope. Take the scope and place it against different areas of the engine. You'll be able to hear what it sounds like, and you will be able to notice a "problem", if there's one. You're all looking at a problem with it pinging. Well, it's a 22RE motor. Alot of them burn oil, or they don't. I have had two pickups, both with 22re motors. One which didn't burn a drop, the other that did.

If you've try all of that with the fuel and tune up, maybe it's time to look at the internal componets, it doesn't take much of a fuel loss to cause a problem.

Hope that helps

[jbowerman76]

For carbon, a teaspoon of tranny fluid down the plug holes works extremely well. Use high grade fluid and run it till its burning clean again. Follow this up with a bottle of concentrated/every 6 months strength combustion chamber cleaner. And advancing your timing to 3 degrees btdc might help with future build up. Also make sure you're not running hot or cold. Complete combustion requires exact operating temperatures.