miketerrizzi

So this weekend, i Installed my friends wide band Oxygen sensor, this give some real world numbers to the Air and Fuel Mixture, instead of a narrow band which only tell if its lean or rich.

This allowed me to adjust my VAFM, the barn door style air flow meter. I took the suggestion of the forums and figured out how might this really improved the air flow mix, from the factory the car is tuned very rich. This allows the car to make some nice power.

I adjusted my spring about 8 clicks , 6 more than the normal suggestion. This made my mixture at idle 17 which is slightly leaner than normal but at redline my AF is about 11 instead of hitting 10, this is actually giving me at 16 to 15 at 2000-3000 rpm and anything higher is still much leaner than what is set factory. by leaning the car out 8 clicks the car is much more gas efficeint, around cruse and there is more top end power because the mixture was soo rich previously. Im still on my tank so Ill be posting my increase in gas mileage.

I also advanced my timing to 16.5* before TDC and Im thinking about going to 20 but this will make my car always use 93 octane since I dont want any detonnation.


Ill take some pics and figure out if there is really any increase since you lose some low end power which is better for crusing on the highway and get more top end since the mixture isnt so heavy

JamesD

I will be waiting for your results. I was wondering when someone was actually going to put a wideband on it to get the A/F better.

James

phorensic

Sweet! Good data. Anybody know if those idle/cruising AFR's are safe? Jeezus, 11:1 is still pretty rich at WOT 8 clicks leaner.

Now, was this on a 22re or 3vze?

suprathepeg

Nicely done. This is very interesting. At 16.5* can you run regular fuel?

miketerrizzi

3.superslow

I am getting a check engine light since my normal O2 isnt hooked up , the heater wire, but my wideband provides the car with a simulated narrowband output , so its tuned to really respond to a narrow band, once im done using my friends wideband.

yah i been running 87, i just finished my tank, but we got a snow storm last weekend and i was forced to put it in 4wheel for a bit here and there, 260 miles on a tank, 17 gallon fill up. 15mpg highway and city. Ill keep posting as i burn thru tanks twice a week. Sorry for my first drunken post, the wording is all off after i looked at it and was too lazy to revise it. Ill give some real world numbers for ya at diff rpm
A/R
idle 750 rpm 17.3:1
2000 rpm 16:1
3000 rpm 15.5:1
3500 rpm 14:1
4000 rpm 13:1
5500 rpm 11:1

you can guestimate the numbers between. This weekend , most likely ill be upping the base timing to around 20*, like i said previously im running 16.5* BTDC and Im using 87 gas since our compression is so low, im assuming its low since we have non interference engines. And I really want to throw my peice of ÅÅÅÅ on a dyno for about 100 bucks and figure what is really going on, because we need to figure out the minum advance for best TQ, too much base timing , even if its not pinging might not be as good as we think.

I did have to mention that the truck does run diffrently, since its lean at idle, around 17.3 the car does seem to warm up faster since its leaner, after the warm up enrichment. And its really quit more powerful in the higher RPM since its not so bogged down with fuel, but there is no jerk of power at idle. I dont mind really since im looking for better gas mileage. Ill be getting 29 inch summer tires as soon as summer breaks
because she feels like a loose v*gina on the highway with my worn A/T

All this talk wants me to get a megasquirt because A/R should be 12.5 at peak tq and be around 16 for fuel econemy everywhere else. Use a speed density system instead of an MAF since a new MAF is about 400 bucks and a MAP sensor is about 10 dollars at a junk yard. Im really stuck because trying to figure out the best of both worlds for the Timing and Fuel trim. since we can only adjust the base timing and base fuel and go from there.

I just want to warn poeple, changing the clicks on ur VAFM is adjusting the spring rate, and lean the mixture which could very easily damage you truck and cause detonation and burnt valves so be carefule. since my car is 13 years old the spring is slight tired, and the clicks on a diffrent year might be diffrent, and the actual use of the car, we can always make an estimate based on mileage, my runner has 156k on it which could be a base figure for how much the spring has been used. Just think if physics and K value of springs, since they are gonna change over use.

Im thinking about getting air shocks since she is sagging like a 80 year old woman. Anyone got any ideas on a brand that works best.


Good Luck and Be safe

trythis

Do you think that summer gas could cause it to run less rich naturally? I am only guessing, but I am wondering if the winter gas could cause it to need to run richer? Stab in the dark, I have no fuel chemistry knowledge.

miketerrizzi

the winter gas usually has ÅÅÅÅ in it so that it can deal with the cold, usually decreasing mileage, no change really in leaner or richer. Summer gas is gonna provide you with little bit better mileage.

This is hearsay, I really dont know so dont quote me or say MikeTerrizzi said so but its not gonna change the mixture.

suprathepeg

I'm really surprised that you can advance it that much. One thing if the ecu is reading an error in the o2 sensor then it'll retard the timing automaticly. You may be advancing it and the ecu retarding it. If you wanna get a good reading run the stock sensor and a wideband and a reader to get a proper reading on your adjustments.

I've heard that 12* is the best you can do on these but nobody has done a good job of watching for pinging and predetonation. I think rather then messing with the AF ratio a 70mm TB would be a better solution and get you the same thing.

miketerrizzi

well im running 16.5* and I know its doing it since i have a really expenisve timming gun. I reduced the clicks this week on the VAFM two about 5 or 6, im still trying to figure out what really seems to be a happy medium between power and gas mileage. I have a good idea of what detonation and pining sounds like because i tune turbocharged cars on a regular basis.

I was going to advance the base timing to about 22* but it started to rain, so when I get under the hood ill give it a shot.

i did fix my CE light this weekend , hooked up the stock heater wires and it disappeared. Atleast the ECU does a decent job of knowing if the sensor is there or not. Im still just bumming about the VAFM settings because it affects closed loop and open loop diffrently. I think i really want to tune it for closed loop mode and not open loop, which normally depends on how much throttle you give the car. I realised im not gonna be really romming the gas much and I rather tune it for granny driving and not having a lead foot. But Ill be posting alll the data that i can get, so us 3.0 poeple can decide, if you floor it alot, u can it leaner which will give u better top end, and the granny drivers for a nice fuel savings.

In a couple of weeks i need to return the wideband so Ill figure it out by then and test whatever i choose with a narrow band , which should provide me with the same results.

Toysrme

*20+ will most likely be far past peak timing.
The last person I knew with a v6 dizzy ran 20* on a Toyota v6 lost an entire second down the 1/4 mile (15.7 to 17.1) & was overheating when cruising.
IMHO - Stay at 16-17 max.

miketerrizzi, you must be exceedingly careful, but don't forget you have an idle-bypass screw to play with also. Remember the adjustment turns exactly in small increments. (1/4 turns)
You're going to have to start making a choice between low throttle, peak torque & peak horsepower. I would richen the by-pass screw & see if you couldn't get more fuel @ peak torque.


It can be hard, nearly impossible to detect mild pinging on the older TCCU's. The new computers drop timing normally 0.25-0.5* per firing, while with the older TCCU's it's nothing for them to jump back & forth several degrees over just one full cycle.
Total pain in the wazoo LoL!

suprathepeg

Exactly, I know that Toyota retarded the timing on the 3vz camrys to reduce overall power but that is a completely different engine and application from the truck there is a point where you just end up working against yourself. Will the wideband in conjunction with the stock ecu even detect predetonation effectively in this application?

Toysrme

Yep, you got it! Regardless of the engine the affect is going to be the same. Normally, if you're a hair past peak timing, no harm, no foul. You're just dropping power & running hotter. Go much farther than that & you'll suffer pre-ignition. That'll take a little power away, to a lot + damage if it's bad, but the main thing is the lost timing. Timing is very, very important to power when you're moving away from the timing peak power is achived at.

Just because I know you like car dynos. Identacle '94 1mz-fe Camry's.
One normal:
http://img.photobucket.com/albums/v4...ta/1mz-fe1.jpg
One with over-sensative knock sensors (but no *actual* problems):
http://img.photobucket.com/albums/v4...ta/1mz-fe2.jpg
Obviously missing 20bhp, but remember both dynos are smoothed, yet look at the responce of engine #2. Could you imagine the throttle responce of that engine by the time you unsmoothe the dyno?
Insane!


A wideband just tells you the A/F ratio. It's not going to help you with detonation, but are an obvious guide as to running lean. There is not set A/F ratio that will cause detonation, it just happens. (I'm sure you could calculate it, but it'd be engine specific. Plugs, carbon, & heat alone would change it from one engine to the next). What you "normally" shoot for N/A is "around" 13.2 @ peak torque, 12.5 peak power.
Under boost (not major all-out boost), you want to get at 12.5 quickly, and stay there. More fuel provides more cooling, but gasoline is very ineffecient at cooling. Those are the rules of thumb numbers you want, but don't gaurentee to be the best for every engine (Or even half the engines out there)
You can trust the stock ECU's N/A to keep you from blowing an enigne up, unless you get bad pre-ignition, under load.
FI... Don't trust any ECU to save any FI'ed engine. The operating parameters change too drastically.
It's a topic for another discussion entirely... But you can effectively tune most N/A engines with a heated narrow band sensor *once* you unerstand exactly what you're looking at, and reduce all the main problems of a lambda sensor as much as possible.



Hey I'm not gonna stop anybody from trying whatever timing they want. I'm the dumb*()&%^ that drove aruond with 40* base timing on my car one time for afew days & couldn't figure out why I had BLAH WOT performance, pinging & was running a half a notch higher than normal.

tomasp

Would like to revive this old thread.
Just got a 92 3.0 V6, very clean truck, however after driving a bit found it was doing around 11 mpg....As I wasn't very confident at that stage (duh) took it to a garage. They read the codes from ECU (even though there was no CEL) and found two codes - O2 sensor and Running Too Lean (huh??)). They took the O2 sensor out, found it clogged, cleaned it well and put it back. Then re-checked the codes - both were gone.
So...in my further quest to tune the engine I am replacing plugs (the gap looks at least 1.5 times wider than that of the new ones from stealership...), distributor cap and rotor (both are quite worn and have quite bad carbon build-up. Also replaced air filter.
I have been reading Yotatech for a while now and especially value Toysrme's input, I think he knows what he is talking about. Following his advice I have leaned MAF by 5 clicks and leaned the idle bypass by 1 full turn. Also been playing with the timing gun and found that I get quite a nice response at around 16-17* - anything less and it doesn't feel like revving happily when asked. Actually had it at around 20* and had quite a bad sulfur smell from the exhaust. Now after retarded to 16-17* and adjusted idle bypass the smell from the exhaust is quite nice.
What about the power? Well, after resetting ECU took it for a drive. Quite responsive, revs fine, needs 2K+ RPM to really get going though - but hey, it is 3.slow, isn't it? Will probably keep the same setup for a day or two and see if I can understand what is happening with fuel consumption and is it powerful enough. Tomorrow will replace dist parts and plugs. Would love to do plug wires but they are so expensive in the stealership (everything is expensive in New Zealand) - will probably have to order them from the States at the end of the day...Does anyone think that i _need_ to replace O2 sensor or will it be fine for some time now once cleaned? The truck has 95K miles on it and is imported from Japan.

suprathepeg

Might be a good idea to put a wideband O2 sensor on it to see how lean you are running. That is a lot of advance and although that may work on a 3vzfe it doesn't necessarily translate to the SOHC engine in your truck. Of course I could be wrong but thats why you should have someone put the wideband on it to ensure you don't end up running too lean or having predetonation both can kill your day real fast.

tomasp

Ok - I have since retarded the timing to 12-13* and set MAF to 3 clicks lean (CW), also 3 full turns out for the idle bypass on the MAF. Truck runs fine however pings on 91 petrol when under load (91 octane in New Zealand is approx 86 everywhere else - they don't know how to make good petrol here). I am still waiting for the dist. cap to turn up and then will replace spark plugs, dist cap and rotor in one go. Also am getting a new fuel filter (I think mine is original 95K miles) and will take the TB off and clean it + adjust TPS.
Really don't feel good having that pinging - should I fill up with 96 in the meantime (which would be around 92 in other countries) just to avoid pinging - but won't I get more carbon buildup then?

celica

I would undo the clicks on the AFM that you did

suprathepeg

Yea you need to know more then that it runs to justify keeping it the way it is.