peckinpah

Last week I started to notice my 22RE pinging on hard acceleration, especially in 4th and 5th gear. It never did this all winter long, no matter how much gas pedal I gave her.

I have heard rumors for years about "summer gas" and "winter gas". And since it's May 1st, I'm thinking maybe here in California they switched over to the summer blend and maybe that's the culprit.

Anyone else experiencing something similar in the past week? Or do I just need to do a tune-up?

peckinpah

Well, either I'm being shunned, or no one knows.

Guess I'll try a tune-up next weekend, and see if that helps.

badattitude

I'm not a mechanic but I don;t think it's the gas. Tune-up sounds like a good idea, especially if's been a few years since the last one. Good luck!

blake.nemitz

i would think the less ethanol content would make it ping less for summer gas, maybe its the oposite

peow130

Try retarding your timing a bit..

Wrenchinjoe

+2 Make sure your timing is adjusted properly during the tune up.

MudHippy

Summer gas to blame for pinging?

Short answer: No

Since it's not the octane rating that changes between summer and winter blends of gasoline, spark knock/pinging wouldn't be an issue. The amount, or presence, of ethanol in the fuel blend will also not significantly affect it's ability to withstand knocking/pinging(I'm talking about gasohol/E10 and gasoline here, so don't try schooling me about the octane rating of pure ethanol or E85. Which is slightly higher than even premium grade blends of gasoline/gasohol...I KNOW THIS! It's just not relevant to this discussion.). A 10% ethanol blend of 87 octane gasoline is, therefore, the same as a non-ethanol blend of 87 octane gasoline as far as it's ability to withstand knocking/pinging. It's all about the AI(Antiknock Index) or pump octane rating. In the U.S. ethanol is blended with gasoline in low percentages with the primary purpose being to improve tailpipe emissions, not for use as an effective octane booster.


http://www.autoshop101.com/forms/h57.pdf

So where are we at now?

Well, if it were my vehicle I'd start with Seafoam Motor Treatment(huge fan of the stuff) to try and remove any built-up carbon deposits in the combustion chamber. Then, if that didn't work, I'd break out the FSM. The engine mechanical troubleshooting section for the 22RE has the proper steps layed out to diagnose the cause of excessive knocking. I'd start, of course, at number 1(Knock Sensor Circuit) and work through to number 10(ECM) if necessary. Correcting any faults that may be present along the way.

http://personal.utulsa.edu/~nathan-b.../3troubles.pdf

You'll notice that number 2 is Fuel Quality. You might just need to switch brands of gas. Or if all else fails, try running mid-grade or premium gasoline, if you're not already.

And if by "tune-up" you mean replacing your spark plugs and wires, that's number 3.

peckinpah

Wow, thanks for all the info. I bought gas last week at a convenience store-type no-name place, because I was in a strange city and was about to run out of gas. Knocking seems to be getting worse, despite the fact that I burned the tank of sketchy gas until it was almost gone, then filled up with what I usually use (Valero).

Fortunately, I have a timing light, so I ought to be able to see right away what the situation is with my timing, which I'm pretty sure is the culprit.

Resto-noob

iTrader: (3)

How's your EGR valve? If not functioning properly, pinging can result.

peckinpah

Never messed with it, I have no idea.

I just did Seafoam, adjusted the valves, replaced plugs, points and plug wires, and set the timing with a timing light less than a year ago. So I'm hoping it just a loose bolt on the distributor cap, or something simple like that.

If not, I'll go through the FSM as suggested by MudHippy, and pray I don't break anything, since this is usually what happens when I attempt to do even simple repairs.

I was also thinking I might run the gas tank low and drain it, in case there's some water in there or something.

Resto-noob

iTrader: (3)

If you want to mess with it, here's how:

Go to autozone or whichever chain store lets you rent tools and get a vacuum pump. Attach it to the valve on the EGR. Run the motor and apply vacuum. If the idle gets rough when you do this, it's good.

https://www.yotatech.com/forums/f116...-valve-116951/

Might be worth a try. Best of luck to you.

MudHippy

That's #4 on the list according to the FSM. So after checking and ruling out #1, that's the next logical step. Could be that the base ignition timing is out of adjustment, hypothetically speaking(but I'll bet my bottom dollar it ain't).

1. Knock Sensor Circuit = Got code 52 or 53? No? Then you're good to go.
2. Fuel Quality = ruled out IMO.
3. Spark Plugs = Not too likely, unless you've driven 30k miles in the last year. The recommended maintenance schedule being to replace them every 30k miles or 3 years.
4. EGR System = Here's the FSM pages on EGR system inspection http://personal.utulsa.edu/~nathan-b...ne/19egrsy.pdf
5. Valve Timing = How's the timing chain holding up?
6. Radiator and Radiator Cap = Running hot will encourage pinging.
7. ??? = Odd, it should be there on the list. But it ain't...
8. Thermostat = See #6
9. Water Pump = See #6
10. ECM = Oh boy...pray to God it ain't that. NOT CHEAP!!!

PS, on the EGR system checks, I've always used my mouth/lungs for a vac pump. Works just fine for these purposes. You don't have to suck very hard to open the valve. Just clean the hose off before putting it to your lips.

razed

did I miss something where winter blends could have more butane (raises RON, no effect on MON) and summer blends have less butane (lowers RON, no effect on MON)?

Pump octane is (RON+MON)/2.

Lower either without raising the other acccordingly and the pump octane rating drops and pinging becomes more likely.

sb5walker

This post has some ideas that may help: http://www.toyotanation.com/forum/sh...41#post2946141

Gasoline & Octane Rating: http://www.toyotanation.com/forum/sh...67#post2588867

MudHippy

I like these.

I find only one small flaw in the information provided.

Toyota has designed the knock control systems on these engines(22RE and 3VZE) to automatically adjust the ignition timing to the octane rating of the fuel available.

What does that mean?

More horsepower and fuel efficiency with grades higher than 87 octane.

AUTOMATICALLY!

No fiddling with base ignition timing required. Just fill the tank with premium/high octane fuel and reap the benefits. In fact you'll find that most, if not all, EFI systems(foreign or domestic) have this same programmed ability. Atleast those with knock sensors(is that not all EFI systems?). Don't feel bad for not knowing this. Most folks don't.

Here, I prove it to be so.

http://toyotareference.com/truck#TR84

Clipped from the 1988 Toyota 4WD pickup brochure I found on ToyotaReference.com.

Also of note, the 3VZE is rated at 150 HP stock on 91 octane ONLY. And only 145 HP on 87 octane. So yeah, can you afford +5 HP in your 3VZE without even having to turn a wrench to get it? I BET YOU CAN!!!!

Looky, I prove this fact to be true too!!!


Ahh..what a day! But it's time for bed. So long 'til tomorrow. When who knows what truths the MudHippy shall reveal....

sb5walker

Glad there's only one small flaw, lol.

I can't discern a spec of difference in power from my veezy with higher octane. That's just a subjective observation, tho, I haven't tested it on a dyno. I can get a noticeable bump if I set base timing to 14 and burn 91 octane, that's definitely true. I don't run that on a regular basis; don't want to push my luck with this particular motor.

As far as I understand, some or all of the 2WD 22REs don't even have knock sensors. Hard to imagine the timing of those varying based on octane, but you could probably get something by bumping the base timing.

MudHippy

IMO Toyota's specs for setting base timing are too retarded for good performance using any octane grade of fuel. So I'm not really an advocate of NOT advancing the base ignition timing to take advantage of increased performance while running high OR LOW octane fuels. It's just, as I myself have recently learned, not a necessity(I used to think you should/had to too). Prior to discovering this fact I actually found improvement by advancing my 3VZE's base timing right off the scale even while running 87 octane. I estimated I had advanced the base ignition timing from the stock 10° BTDC to ~20° BTDC before having limit it there. It never produced any excessive pinging under any conditions with my 3VZE at that setting. The limiting factor being a properly steady idle speed. Too far advanced and it just won't idle right(too lumpy). After all the base ignition timing is nothing more than the ignition timing angle AT IDLE SPEED.

Nowadays I run it on 91 octane with the base ignition timing set nearly as advanced as is physically possible. I've able to set it several degrees even more advanced and maintain a good smooth idle with the higher octane fuel. It's now running just how I like it with the base ignition timing set at ~23° BTDC. Still no excessive pinging neither. As a matter of fact, I can hardly make the thing ping no matter what I try. It's only because I have acutely sensitve hearing that I can detect but the slightest of pinging under conditions where it technically should. No one who has ever rode with me can even hear it at all(I keep asking "can you hear it now?" Reply = "No").

I know it's inherently risky to fool with ignition timing. You can cause catastrophic damage if you're not careful in doing so. Minimally you can cause additional stress/wear and tear on many of the engine's components. But I can't resist the temptation. When all I have to do to get a decent power boost is spend $.20 more on a gallon fuel and/or advance the base ignition timing a bit, how can I?

More of the good stuff.

peckinpah

Got out my timing light and checked the timing. It was fine.

Meanwhile, the pinging has stopped all by itself. I'm not 100% positive, but I'm gonna chalk this up to filling up with bad convenience store no-name gas. I should have been more skeptical as to why it was 10-15 cents cheaper than everyone else's gas. Now I know.

But your tank is empty in a strange town. What else are you gonna do?