Very good, couldn't have done better myself. So Rob is right that you don't want the pipes too big, but for the (often quoted) wrong reason. The bigger pipes can actually create more back pressure if they are too big. Also, sorry for the hijack.

 

When was the last time the fuel filter was changed? A clogged fuel filter can also cause a lean condition.

 

Just one more note on the backpressure thing. While it may be true you don't want too much backpressure, you also do not want to have no back pressure at all, at least not with a small engine like this.

 

Yep. Shorted and at 5 degrees btdc.

I have heard nothing but great things about seafoam, but to be honest snake oils worry me...

When I had the engine apart recently and did the head and timing I also cleaned the TB and intake before I put it back together. I used a ton of TB cleaner and brushed, scraped, and dug as much of the crap out as I could.

I am wondering if the cleaner I used might have eaten all of the grease out of the TPS. I have heard that there is some lubrication inside it that it needs to work right. It may just be sticking. I'll check that too.

I'm not too keen on the seafoam but if all else fails I'll buy a can and try half through the intake and half in the tank.

 

I don't have a cat anymore... I'm one of those bastards you keep hearing about these days. Any other reason I need backpressure?

I'm sure my new pipes hold heat better than those rusted pieces of crap they replaced.

I don't consider it hijacked, its just multi-purpose now. All of this is relevant.



Btw, I got the new pipes done yesterday like I said above and I'm pretty happy with them. I don't think it softened up the bottom at all either. If anything it gets up and goes better all around now.

Sounds throaty too.

 

The TPS doesn't have lube inside but it is a sensitive electronic instrument; if any cleaner got inside (it's not sealed) it could ruin the circuits. If you already did all that to the intake the Seafoam isn't going to change anything.

 

Ok... Here's what I did today.

After quite a bit of research on plugs and heat ranges, I decided to try a NGK plug with the next cooler heat rating. NGK says that as you do mods that raise compression and perormance, you also raise cylinder temps which can in turn cause parts of the plug to glow and cause predetonation. Each step cooler tolerates 70-100C of cylinder temp. It was very interesting reading and I recommend it to everyone if you don't know about this...

http://www.ngksparkplugs.com/techinf...000&country=US

More good links on spark plugs:

http://www.spark-plugs.co.uk/pages/t..._technical.htm
http://www.carcraft.com/techarticles/spark_plugs_tips/


Here's what the old Bosch Platinums looked like:



They don't look too bad, but they do look a little lean to me and there appears to be some evidence of detonation on #1...


All I could find locally and only one store had them were the Vgroove NGK BPR6EY's Stock #6427. So I got 4 of those at around $2.50 each.



And reading in the above links about gap, I decided to gap just a little more ambitious than stock at .36-37" with stock being .31" and the NGK pregap .32". I regapped them and installed them.

I also did a new cap and rotor.

I also decided to adjust the AFM while I was doing all of this because I kept seeing reference to a lean condition causing pinging too. Not only do most engines run a little lean from the factory for emissions, but I also have an improved flowing head with a cam and bigger valves, and now a free flow exhaust too. I figured it should be an easy mod that is reversible.

This was a little more than I bargained for due to the fact that my AFM in my 95 truck is different than all of the AFM's I have seen in pictures.

Here's what I was expecting to find:



Here's what mine looked like upon opening up the cover:



After figuring out where the adjustment needed to be made I marked the current tooth:



And went two clicks CCW to richen it up a little.



Now, with these mods, adjustments, and new parts I decided to try going 8 degrees btdc on the timing to see if I nailed the problem, but I got a little pinging low in 4th gear. There was much less than I had before, but it was still there. So I went back home.

Next I tried 5 degrees btdc and remembered to pull the ECM fuse in the truck to reset it. I went back out and was barely able to get a little rattle in 3rd at a constant light pedal, and I think I heard a little in 4th too. It's almost gone but I still got it to ping.

The engine is running noticeably better, and ran downright great when I had it set to 8 degrees btdc, but I still have the ping.

Strange enough, Somewhere in all of this the idle all of a sudden increased about 500 rpm and I had to go almost 2 full turns in on the screw to bring it down. Idle was very smooth after that. i have no idea what happened... Pulsation with AC on and brake also completely disappeared.

I think I have it narrowed down to the TPS which I definitely cleaned the TB with it still mounted, or the temperature sensor in the TB.

Next on my list is testing and adjusting the TPS, possibly a 180 degree tstat, coolant temp sensor, and then I'll start grasping with the fuel filter and whatever else I find.

Diagnosis: Today definitely helped but I can still get it to ping.

 

And the TPS testing...

The readings are a little off, but it seems to working ok...

 

It looks like your number 2 reading is off enough to cause a problem. A little off with these things means it is notworking right. You said that it pings with just a little pedal and isn't that right where it is reading incorrectly? Your #4 spot is off as well.
I would replace it, or adjust it if you can. If you got cleaner in it, it probably will corrode and stop working well after some time for the electronics to dissolve.

Take the TPS off and see if the spring inside is snapping back to the 0 point. If it is slow to return, that means is it needs replacing. THey really do make a huge difference in drivability and throttle response.

 

trythis: #2 is not off; it says LESS THAN 2.3k, which his is...???
Also, @4 is OK as well because it is between 3.1k & 12.1k (3.2k)...???
HOWEVER, the #5 reading is low because it is supposed to be between 3.9k & 9k, where his reads 3.64k.

He just needs to be sure to have the correct spacer between the lever & stop screw when when he reads the resistance.

Which one of us is misunderstanding this?

 

oops, my bad.
#2 is good. And if #4 being off that little bit is all that was bad, I wouldn't sweat it. SOooo. nevermind my earlier post.

 

The numbers I posted are a little hard to read because with the meter set to 20k ohms was the only place I could get consistent readings. The howto page I read said that 20k is not 20,000, but rather 1000x lower which would put the readings with the decimal place 4 to the right and close to in spec. The reading #1 is right at the upper end of the range but its still right there.

I don't know what the last one is for, but it is a little off. If I understood the test right it was with no spacer and just reading off vcc and e2... Seems like the same test as #1 but in different prongs.

I'll check how it is running better while doing my normal work drive this week. I drove it some last night and it actually seemed a little sluggish and the idle dropped down momentarily then came back up.

From the way it felt, it seemed like I needed to up the timing a degree or 2 and possibly put the plugs back to the recommended gap setting... And maybe even back off one click on the AFM. I could hear a difference in the exhaust tone due to being richer even at idle.

If it runs like that on the way home tomorrow I'll probably make a few adjustments.

I didn't get a chance today to mess with anything.

 

>>>*Morning!
Got your email, thanks for the link. I have been chopping wood so I am way behind on most of the threads. Plus I apologize for any repeats here, I didn't have time to read all the posts yet.

*First, let's talk a bit about what "pinging" or spark knock really is. It is two or more flame fronts running into each other, or preignition which is just the flame front going off a bit early in the piston cycle.

The next step is detonation which doesn't really demonstrate until you hear the loud noise and see big cloud of smoke. Detonation is all of the fuel and air reaching it's distillation point and going off at once, this always happens after TDC.

If all is normal, you will hear a small amount of pinging under light throttle that goes away when the load is increased. What drives a person nuts is an engine that pings at cruise, my old GMC truck did that until I replaced the EGR valve, and that might be part of your problem.

The causes can be many, but the first place to look is the spark plug heat range. The next place to look is carbon deposits in the cylinder. This actually is possible since retarding the timing helps for awhile but the concern returns. With your symptom I would suggest a compression test, I would be looking for a higher than normal reading.

"RV" style cams can contribute to pinging if the valve timing is advanced too far, the fun part is the same thing can happen if the valve timing is too late because heat will collect on the exhaust side of the head, eventually creating hot spots.

A timing assembly running looser than it should will radically increase wear. Chains don't "stretch" as much as they wear at the trunion(pin) and the roller. We can see quickly that just .001" wear on each of 96 rollers piles up to a lot. Then the valve timing is wandering back and forth, performance suffers.

In your case, I would do as already suggested, start with the spark plugs. It is hard to top the spark plug Toyota suggests, just MHO. Then service the EGR, and it sounds like you have been through all the tuning systems.

So that leaves the exhaust system. A very free flowing system will lean out the engine, and since we are at 9.5 to one already with the 22RE she is already right at the edge of thinking she wants premium. I am tickled that you are taking solid steps to find the concern, because a mild ping that clears up is harmless, a heavy ping that increases with loading is bad news and next is reaching into your pocket for some hardearned.

The exhaust system should have backpressure at the port exit, but after that the energy is used so the goal is get it out of there. We find 2" into the muffler and 2 1/4" on exit all the way back is about right for an engine that is seeing normal use.

One more thing: Advancing the timing too much will not increase power. Typically the stock setting is always correct. There are situations where the engine can use added, normally when combined with other mods like exhaust and fueling sytem changes, but what is interesting is that as we improve combustion chamber efficiency we often find a requirement for less advance.

One thing is true here, if you can run at full throttle uphill without pinging, then you are real close to correct. A temporary very light ping at part throttle is a sign of best economy.....*EB

 

As always Ted your input is greatly appreciated. Thanks.

The timing set is new from a few months ago and is one of yours so you already know the quality of the set.

When the previous chain went I bent the intake valves so I also had to pull the head. While it was off, I'm not going to claim completely clean pistons, but I did clean a lot of the carbon off them. There probably is still enough though that it could probably benefit from a mild sea foam treatment next time I feel like replacing the plugs though. I'll keep that in mind.

The EGR system is the one that came with the truck and it has 205k on it. It probably needs attention I'm sure. I'll do some studying on it and see what I can do.

Not knowing just how much of the thread you did read, I have changed the plugs to NGK V-powers and gapepd them a little larger than stock at .36-.37. I am going to regap them when I get a chance to the .31 Toyota recommends and see if that kills the rest of the ping. They are the next cooler plug that NGK makes. They are a '6' instead of a '5'. Is that the direction you'd recommend going with slightly raised compression and performance?

I did a compression test when I did the head a few months ago and here is the result:



I was questioning if it was a little high when I posted it back then too.

Your closing statement is just about what I'm hearing now. It's mainly a ping at very small throttle openings in 3rd and 4th gears and I'm pretty sure it goes away when I floor it.

I'll try to worry a little less about it I guess. I just try to listen and smell what my engine is telling me to avoid problems.

Thanks again Ted.

 

If i do the AFM mod here, should i gap the plugs up to say 35???

 

Honestly I don't think the bigger gap did anything at all. As a matter of fact, I considered taking the plugs back out and putting them back to stock.

Side note, as the temperature out is finally starting to cool off a bit I think my problem is lessening.

Yesterday I finally figured out I pulled the wrong EFI fuse so I pulled the right one, and put in some octane booster. It was also raining on the way home and I had no ping at all. Of course I'll have to listen when it isn't raining, and I can't keep running octane booster in it every tank, but at least it wasn't pinging for once.

I still haven't gotten around to fooling with the egr. It's been so hot and humid out I haven't felt like doing anything outside.

More to follow...

 

how does one service or work on the EGR?

your pining issues sounded EXACTLY like mine in the 3vz-e. But I also had carbon deposits literally hanging from the cylinder head and growing on the piston surfaces. (Stalagmites and stalagtites!) lol

 

EGR: go through all the diagnostics in the FSM that test sensors, valves, etc. When something comes up bad, replace it. EGR vavles are pricey though. Cleaning out carbon is a pain, my EGR diaphram was full of black, liquified goo. The shaft was completley frozen in carbon. THe tube running through the intake plenum was clogged and most of my vacuum hoses were stuffed full of that same goo. Changing that stuff out helped with vibration, power auto tranny shifting response.

 

I have just modded the AFM, i went rich 2 clicks, do i need to adjust the screw in as well? I have mine at 5 BTDC and i get pinging from Hades, all of my in stall on the timing chain went well, im not sure if i put the correct bolt in where the chain tensioner is, ive gotta pull the cover and make sure the bolt is touching the tensioner, the drivers side is tight as far as the chain goes. Can someone show me a pic of this bolt?

 

I'm pretty sure it's the one in the very center right above the oil pump that can touch the tensioner.

When I put mine together I could take the valve cover off and look down at the tensioner with a flashlight and see the end of the bolt sticking in. The tensioner has a small notch to allow this, but I went ahead and ground the bolt down so it didn't protrude at all.

You can most definitely see it sticking out of the cover right at the front of the tensioner if you look in there...