Pinging

[Toy4x4]

'93 Toyota 3VZ-E 4x4

Getting a lot of pinging under acceleration as well as intermitently on level ground/slight rises. Hate to think what it would do going uphill.
I cleaned the throttle body a few days ago and it seems to be a little worse now so I'll go back and redo it. I'm thinking of getting a timing light and retarding the timing 1-2*.

I've heard its bad to switch octanes as it leads to carbon buildup so i don't want to go that route.

Any other tips/tricks or parts I should check out?

 

[Steve S]

I would first use a real good injector cleaner ,look for vacume leaks ,make sure the egr is working. buy a service manual. Don't do any guessing as it may be a simple repair and blindly adjusting things will dig you deeper into do do.

[ September 16, 2003, 01:03 AM: Message edited by: Steve S ]

 

[Toy4x4]

I guess I should have mentioned I had the 120K service done a few months ago so any pertinent parts were switched.
Injector cleaning was done and I currently run Neutra (2oz per 19 gallons) as a maintenance dose.

How do you check the EGR?
I'll check the hoses.
I've got a Haynes manual (

) but am finding out its not that great.

 

[Mike_dup1]

What is probably happening is there is carbon build-up in the combustion chamber, thus reducing the compression, causing the pinging. You could try to run some over the counter gas treatments but they are not always successful and can be a waste of $$. Pinging is rampant in gas engines.

For some reason with all this pollution equipment engines tend to carbon up no matter how the car is driven.

[ September 16, 2003, 07:54 AM: Message edited by: Mike ]

 

[BOBISTHEOILGUY]

Toy,

first, you are a canidate for running some full bottles of neutra through there to start with. I'd run at least 3 full bottles(1 each tank).
2oz per 19gal's way to low for it to be effective.

Pinging is normally caused by poor burning and poor gas. Most of the toyota engines are designed to run standard 87 octane fuel. In fuel, you have sulfur, which, when burned, turns into sufuric acid which becomes harden carbon attached in the cyl. This carbon, after being built up, will get hot while engine is running and act like a piece of coal, and stay real hot, so when the fuel goes into the cyl from the injectors, the hot coal carbon will ignite it before the piston gets back to the top of the cyl. This is where the cyl is "firing" and causing the engine to work hard getting back to the top, causes the engine to ping,(pre ignition knock), creates lack of perfomance as it is working against itself, and of course drives you insane. By increasing the octane of fuel, all you're doing is getting a fuel that burns slower than the 87, so that the coals in the cyl cannot ignite it as easily, and will cause the pinging to go away, but then because it isn't as efficent of a burn, it tends to leave more carbon in the cyls.

So, to help this, take and definatly increase the amount of 131 directly into the fuel. One thing that may happen as well is that when it starts to break things loose, it will cause the engine to run like crap, but just keep driving it for about 5 miles, and this will go away as it will keep cleaning the cyl.

Another little trick that one toyota mechanic told me he did after the neutra was to goto an aftermarket type of full flow air filter simular to the k and n, which increased his air. He stated that this made a good difference as well.

Another thing I did, was to take the 131 and do a spray into the plentum to help clear out the intake as well, but you do not want to just dump directly into it, but mist it in. This is one of the things the toyota does to help drivability problems such as that.

Hope that helps.
bob

[ September 16, 2003, 08:28 AM: Message edited by: BOBISTHEOILGUY ]

 

[MRC01]

quote:

---

Originally posted by Toy4x4:
Getting a lot of pinging under acceleration as well as intermitently on level ground/slight rises. Hate to think what it would do going uphill.
Any other tips/tricks or parts I should check out?

---

Using a higher octane fuel is just a bandaid, doesn't solve the problem only makes the symptom go away.

Check the timing to see whether it's in spec... but retarding it out of spec is just a bandaid.

An overly lean A/F ratio can cause pinging. Common causes of a lean condition: leaks in the intake, clogged fuel filter, clogged carb or fuel injector, dirty MAF.

As others have mentioned, carbon buildup in the combustion chamber can cause pinging. Not sure what to do about it, though; there may be fuel additives you can use that will break the crud free. Just hope it doesn't score your cylinder walls on its way out.

 

[BOBISTHEOILGUY]

As others have mentioned, carbon buildup in the combustion chamber can cause pinging. Not sure what to do about it, though; there may be fuel additives you can use that will break the crud free. Just hope it doesn't score your cylinder walls on its way out.

Schaeffers 131 doesn't break the crud/carbon, but softens it to the point it can break down and disperse through the system without damaging any internals. Hard carbon would have to be chipped off otherwise.

[ September 16, 2003, 10:43 AM: Message edited by: BOBISTHEOILGUY ]

 

[Toy4x4]

I had the intake cleaning done along w/ the injectors (sorry, was late

). I can still see some carbon, though, when I look down the throttle body.

I have used Fuel Power @ 3oz per tank (19).

I did have a K&N system on the truck but after reading about them on here

and looking at the oily dirt residue in the intake tubes, I went back to stock.

I've tightened all fasteners on the intake tubing, fuel filter is new.

How does one clean the MAF sensor? I've heard they are VERY delicate and sensitive.

Bob, I looked at the bottle of Neutra and it says "SOY ULTRA". Is this 131 or 131C? If its the 131C, use the same amount?

Thanks all.

 

[Terry]

Toyo 4x4 did the FP help ? How long have you given the chemicals to work in how many miles ?

If not Molakule has a mix of FP and Nuetra that may clean the CC issue more thoroughly. I am asking his permission to post it here.

Both FP and Nuetra are serious fuel side cleaners.


Sounds like You need a mechanical repair if you have attempted cleaning for hundreds of miles and no success.

 

[Terry]

Mix ratio is 1 qt Neutra to 3 qts FP. The treat rate 1 ounce to 5 gallons. Mola has posted that here before somewhere.

I have not used this but plan on it. Mola and some of my analysis customers who have tried it says it removes really tough deposits.

The throttle body deposits on the air side are going to have to be cleaned with a foaming cleaner like Amsoil Powerfoam or similar cleaner.

Once doing the cleaning with the spray stuff your TBN of that oil is going to neutralized so change the oil NLT than 500 miles after the cleanings.

The fuel side adds should NOT affect the oil that critically ,if used at suggested treat rates.

FP won't in any dose, Nuetra if used at super high treat rates will affect the TBN and adds some.

Once again I suspect a mechanical issue more than deposits as the earlier cleanings should have helped. Your comments do not indicate that they have. DO clarify that please.

 

[Mike_dup1]

quote:

---

Operated by either electronic (computer/
servo) or mechanical (vacuum) means, EGR valves
are designed to be closed at lower engine speeds. At such speeds, combustion temperatures are relatively low and NOx production is at a minimum. As speed and loads increase so does the combustion chamber temperature. The EGR valve will then open to minimize the temperature and resulting increase in NOx production.
If the EGR valve malfunctions engine performance
is dramatically reduced. A EGR valve remaining
in the open position will result in the engine
to stumble or stalling at idle speeds. In the event the EGR fails to open, combustion temperatures can not be limited causing higher cylinder temperatures and an increase in NOx emissions. Engine pinging or knock may occur, especially when the engine is under load.
In either case, drivability problems arise and NOx control is lost. An additional drawback is that the loss of the NOx control results in a rapid degradation of the motor oil being used. Shortening the oil’s life, NOx results in increased oil nitration and a depletion of its ability to neutralize acids (TBN) and maintain internal cleanliness. The results are oil thickening and/or the formation of sludge within the engine.

---

[ September 16, 2003, 03:01 PM: Message edited by: Mike ]

 

[Toy4x4]

I still had pinging after the cleaning was done, though not as much. I do not know what type of cleaner was used.

I used FP for about 3 tankfuls (800 miles approx.), but noticed my mpg went down by 1 so I stopped treating.

As for the Neutra question (above post), 131 or 131C?

I'm beginning so suspect it the EGR valve after reading Mike's post. When the engine gets hot, its at its worst. I had a bad PCV valve and was burning oil for a while.

I've just finished recleaning the throttle body so I'll go out and give it a run.
Appreiciate all the help.

[ September 16, 2003, 03:31 PM: Message edited by: Toy4x4 ]

 

[BOBISTHEOILGUY]

Toy, that's the 131c you have. The 131 says neutra on the bottle only.

the soyshield is a different product.

 

[Drew99GT]

You do live in AZ, where the detonation is going to be more of a problem then probably any other part of the US because of very high ambient temperatures. Perhaps 87 octane is just not enough detonation resistence for your climate. Also, try construcing some sort of shield for the snorkal on your airbox so it gets as much cold air as possible. I've done this on many vehicles and it really does help. When under hood temps skyrocket in high heat and stop and go driving, performance suffers and detonation increases substantially.

 

[Propflux01]

One Question. Does the engine use ANY oil? Even a little oil getting past the valve guides will make an engine ping like mad when warm. Best way I ahve found to test that is if 93 octane doesn't make the ping go away.

 

[Toy4x4]

I think I found out what it was. After looking at the thread on cleaning the MAF sensor, I decided to check mine out. Toyota's are engineered differently: no wires, only a door (w/ a sensor

) that registers air flow. So I cleaned that passageway and started to put everything back together. I'll back up a bit now. A couple of years ago I had a K&N Filtercharger system on and one of the bolts broke which loosened up the intake tube to which the MAF was attached. I had to duct tape it together until I could get it repaired. Repaired it, but the duct taped left a lot of residue on the end of the MAF sensor and the attached tube. I didn't think this residue would harm anything. Back to present...I decided to clean up this leftover gunk (now pretty hard) w/ throttle body cleaner while it was apart. Got it all off and reattached intake tubing. Well whaddaya know...most of the pinging has stopped. I guess those hard gunk bits were letting air get by the seal after the sensor and messing up the computed air/fuel mixture. I guess it should be retimed, now.

 

[97tbird]

Toy 4x4,

a few days ago, you replied to my post about me getting my my MAF cleaned, perhaps you can remember. It was easy to get to my maf(97 t-bird), perhaps you can get a service manual, or look online in some tacome web-site(forums), and find out how to get to the maf on a tacoma. I got all the info i needed at a t-bird forum on-line. they really helped me with it. try to seach with "tacoma", and you mind find a site that offers help. "maf cleaning" also brings up results, but not for any specific vehicles, but still good general advice/info.
my maf cleaning was really good, after 1 week, still no pinging, and the car starts a LOT better, instantly.
If you do find how to get to your maf, let me know, and I'll try to help with any further descriptions on how to do it. if you have steady hands, it's possible.
Good luck!

 

[Toy4x4]

97tbird,
Thanks, but I did take off the MAF sensor and it looks to be a sealed system. Nothing is visible from either side of the hole other than the spring-loaded door. I am guessing that there is a sensor that somehow registers how far the door is open and sends that info to compute fuel delivery for mixture. There are no wires at all. Nothing to clean other than the door and passageway. I've asked quite a while back on a Toyota forum and was told not to touch anything else (no way I'm breaking the seal on the top of the MAF

).

 

[shortyb]

Same kind of problem seemed to have happened with my 00 Xterra. I had been using 93 octane fuel for most of its life. 87 is minimum recommended so the 93's extra additives were precipitating out as deposits in the combustion chamber. I used a one time treat of BG44K, which is fairly aggressive. It took approx. 40% of the deposits off but left a very rough and uneven surface on the piston crowns. I confirmed this with a boroscope and with help of Terry, we determined that the increased pinging was probably coming from the uneven deposits on the piston crown preventing a smooth flame propogation. A few treatments of Nuetra and Fuel Power (in higher ratio than maintenance doses) seemed to have cleaned the CCs almost to 100% through another boroscope inspection. This may explain the increased pinging in your case as well.

 

[Toy4x4]

shortyb,
I solved the major pinging issues (see 3 posts above). I have FP in the tank right now and have some Nuetra on the way for Molakules formula for a few tanks of gas. I might get a timing light to see if everything is ok on that end as well since it was timed w/ the intake leak (don't know, but its a good excuse to get another tool

)