My 22re pings. The only way I've been able to get it to stop has been retarding the timing to 0 degrees. I tried turning it back to 5 degrees BTDC yesterday just for the hell of it and it pinged worse than it ever has.

I checked the ECU for codes and found nothing. The needle on my temp gauge reads at about 1/4. I passed emissions a few months ago. If I was running lean or hot or had a bad knock sensor or O2 sensor, wouldn't this throw a code, make my temp gauge read high, or make me fail emissions?

I'm trying to rule out possibilities here. I checked out the EGR system and it is working properly. I run NGK plugs.

Maybe I've got a bunch of carbon in my combustion chambers. For that, I've done the whole water into PCV vacuum tube thing, but maybe I didn't run enough. I used about a pint through a squirt bottle.

I ordered some new plug wires even though the ones I have look fine. I have a spare distributor I can try swapping in.

I'm really at a loss here. I don't like running with my timing retarded because it really does have a noticable impact on power, and the 22re has little to spare.

 

Did this happen after a recent fill up or have you tried a different tank of gas? It could be from a crapy tank of gas that has dirtied up an injector or two.

 

It's done it for as long as I've had the truck. About a year. It used to be that if I put 93 octane in it, the pinging only happened on the highway and was light and intermittent. It always did it though. Every highway trip meant some pinging.

I didn't like that so I clocked it back to 0 degrees and the pinging was almost gone. At 0 degrees, it doesn't do it at all if I run 89 or better, but does ping just a tad on 87... I've left it like this for the winter but now that it's shadetree mechanic season again, I'm trying to sort it out. I set it to 5 degrees BTDC yesterday and it pinged quite a bit, just driving around town. Something's not right.

 

Possible Causes:

1. Carbon Buildup
2. Overly Advanced Ignition Timing
3. Bad fuel
4. Lean Mix
5. Malfunctioning EGR system
6. Overheating
7. Malfunctioning Ignition system
8. Malfunctioning ECU

Have I left anything out?

I can rule out overly advanced ignition timing because I've checked the timing with a timing light and it's pinging badly when set to spec timing.

I can rule out bad fuel because it's been doing this for as long as I've had the truck (a year) and does it no matter what octane gas is used.

Can I rule out a lean mix? That would throw a code 21 (bad O2 sensor) or code 25 (lean fuel mix) code, wouldn't it?

I've tested the EGR system and I think it's working fine.

Overheating I cannot rule out completely. The system seems to be working fine and my pinging doesn't seem to care what the ambient temperature is, although it doesn't happen until the engine is warmed up.

Malfunctioning Ignition System - Maybe, I don't know. Seems like a stretch. I've already tried changing cap, rotor, plugs. I've got new wires on the way.

Malfunctioning ECU - Could be, I guess. This seems kinda far fetched to me too though.

Have I left anything out? Have I ruled out anything I shouldn't have or failed to rule out anything I probably can?

I'm leaning toward carbon buildup as the culprit but I've already tried blasting that out with water in the PCV vacuum line. No noticeable difference. Maybe I need to get more aggressive with that fix. Ugh.

 

A few have written that moving down to a 180 degree thermostat has solved pinging issues. Just passing on what I've read.

If you've cleaned out the carbon and everything else checks out ok, it might be worth a try. The factory thermostat for the turbo engines (22RET) is 180.

 

Had a compression test done?

Can you explain the process, with as much detail as possible, that you used to set your timing?

 

Would a plugged cat converter cause this? I agree you need a compression test.

 

i would second the previous comment about carbon buildup on the heads/valves.

Also, perhaps teh mechanical and/or vacuum advance is out of whack and advancing the timing too far when you accelerate.

 

abecedarian:

To set the timing, I bring the vehicle up to operating temperature, then shut it off. Then I jumper the E1 and Te1 connections in the diagnostics box with a piece of wire. Then I connect a timing light to the plug wire of the #1 (forwardmost) cylinder. Then I fire the truck back up and use the timing light to find the where the notch on the crankshaft pulley is when the #1 plug fires. I loosen the adjusting screw on the distributor and turn it to change the timing.

I haven't done a compression test but I will soon.

Frank:

I think a plugged catalytic converter could, but I've replaced mine since buying the truck.

Gnarly4X:

I didn't allow the engine to ping for a year. I turned the timing back to 0 degrees so it wouldn't.

I pulled the plugs the other day and was actually surprised at the amount of carbony-looking stuff on them. In the past they've just been a tad ashy looking. This time they had some crusty black on them. Weird thing was the ones that were blackish were mostly only black on one side. I'll pull them again and take pics when i do a compression test.

The engine has 176k miles on it.

Valves were adjusted last summer, about 8 thousand miles ago. That didn't make a difference in the pinging.

I haven't checked the TPS.

Lately I've been using the vehicle for mostly short trips. That supports the carbon theory. I do take it out on the highway at least once a week to get it fully warmed up though. Even when I was getting it fully warmed every time I drove it, I still had pinging. The pinging is worse now, and so's the blackness on my plugs...

I haven't added anything to the fuel.

I don't know if there are vacuum leaks. I can't find any, anyway. Would it throw a code and/or cause me to fail emmissions if it was running lean?

MrPeepers:

"Also, perhaps teh mechanical and/or vacuum advance is out of whack and advancing the timing too far when you accelerate."

That could be. Another thing is that it only pings under load. I can be driving along with the timing set to 5 degrees BTDC, having it ping reliably when I try to accelerate, and then if I shift into neutral, I can rev the engine all I want and I can't make it ping.

Thanks everyone for the help so far.

 

Ive experianced the same issue recently.
I think its probably crap gas.
I just did a complete tune up with OEM parts,valve adjustment,fresh coolant etc..

Mine pings lightly under load in 3rd & 4th gear under moderate to heavy acceleration.

 

I would try replacing the fuel filter if it hasn`t been done in a while, and also check the 02 sensor.

 

Both have been done in the last 1000 miles.

I dont think my problem is not enough fuel.I can adjust my fuel mixture on the fly and the problem still persists even when the mix is richened up.

Timing maybe?

Im still betting its the crappy gas.
Remember when gas was pink?

 

How many miles on the timming chain ?, if it has over a 100.000 miles on it, then it could be stretched out and that can throw the timming off.

 

Thx Gnarls
I have 10 k on a dual row chain w/steel guides.

 

Wilshire, I had the exact same issue with my 22RE....EXACT...and here's the bad news...I never solved it. The engine had no carbon, everything worked, nothing was clogged, maladjusted, etc, etc, etc. I had the engine rebuilt for unrelated reasons(actually, the erstwhile-pinging ATK rebuilt engine with 60K miles on it was unrebuildable, so really they basically built a 22RE from scratch!) and now it never pings. The ONLY clue I have is that they put a new knock sensor on the new engine instead of reusing the original one. But the folk wisdom here on YT says "...knock sensors never go bad..." I suffered with that pinging for so long, that if you ever solve it , please post about what fixed it, 'cause I never was able to fix it. Good Luck.

 

I've had my '89 for about six years now, and it does ping on 87 octane under load. Worse in summer. I asked my brother about it. He bought the truck new. He said its always done that. He had it to the dealer and they borescoped the combustion chambers. Everything normal.

A couple of days ago I got a tank of Shell 91 octane (supposed to be, and what I paid for). When I got out on the freeway, I noticed it pinging and not expected. After 100 miles and before the mountains (several long 6% grades) I stopped in Chevron and squeezed as much premium in as I could. Helped a little. I ended up having to go down to 3rd gear and 45mph for several grades. Next fill-up was Chevron premium and pinging gone.

I think tha 22RE pinging in warm weather is just the way it is. I quit worrying about it, and stay out of the throttle if it indicates pinging. Hot weather; extended freeway trip; hills;...I just anticipate and fill-up with premium. Just the way it is. My $0.02