[help needed] 3S-FE soon to be 3S-GTE 1995 Rav4 2door

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Roo-Barb
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3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

Hi all
I am a super noobi.
My Son has a 95 Rav4 and wants to fit a 3S-GTE , so I suggested to him that it would be the perfect time to start playing around with the EFI/ECU.
So i went ahead and bought a Frankenso kit and harness and a spare rav4 ecu, so that we can start to play.
I also have a spare 4S-FE sitting outside that I may put in a frame and build some sort of rudimentary water pump style engine dyno, just to load it.
All three engines have the following crank sensor system: Quoted from Rav4 forum:
Interesting..............
Ok schools in...this is interesting.... it appears the reason Toyota uses a cam position sensor and a crank angle sensor is each sensor controls a specific function. Toyota decided to control the fuel injection timing, by using the signal (called the G sensor signal) generated by the cam position sensor. This sensor tells the ECU when the #1 cylinder is on the compression stroke. That information is sent to the ECU and in turn the ECU calculates the correct fuel injection timing based on the #1 cylinders compression stroke. The Crank Angle sensor send its signal (called the NE sensor signal) to the ECU and when combined with the G signal the ECU can determine the engine RPM, crankshaft position for ignition timing and to detect any engine misfire. This system locks the engine timing to a pre-determined non-adjustable setting. That is why the ole RAV engines need to have the timing checked with jumpers inserted in the diagnostic harness and checked without the jumpers inserted. The values of the timing need to fit into the range Toyota has programed into the ECU.
I again apologize for the bad info, I shot off my mouth based on my experience with Nissans which allow for some manual ignition timing adjustments independent of fuel injection pulse or phase.
MaxDoc
How will this affect the expected signal to the RusEFI unit.

Also has anyone else used it on a Toyota small engine?

Thanks in advance

Really looking forward to getting started my RusEFI is at the post office so I will get it tonight.

I have also purchased tuner studio.

Thanks Greg. :mrgreen: :mrgreen: :mrgreen: :mrgreen:
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kb1gtt
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

That doesn't sound like much of an issue. What is needed is a detailed knowledge of the wheel pattern. As well you'll need to know if it's an analog signal like VR, or a digital signal like Hall.

Once the wheel pattern is known, we can compare it against the existing wheel decoders, and see if we already have a decoder to work with, or we'll have to create a new one which is a common process and can happen usually in a couple days to a week or so. However the pattern needs to be know.
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by AndreyB »

There is no way for us to know what exactly Toyota does, we would have to roll assuming that all internal combustion engines are pretty much the same thing.

We have a way to control injection phase as long as you know what injection angle you want at which RPM and which engine load, but as Jared says it all begins by having crank/cam shafts connected and signal shape encoded so that rusEfi can decode it from the wires.
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by blundar »

12 evenly spaced teeth on crank wheel
1 tooth on cam sensor
mag (VR) sensors
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by blundar »

and toyota vr sensors tend to age poorly and are very finicky to deal with. specifically very low voltage output at low rpm while cranking.
Roo-Barb
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

Thanks Guys

Picked up the 3S-GTE today. got to familiarize myself with it.
Came with a Denso ECU to my surprise as the other 2 models and earlier had Fujitsu TEN ECU's and they were easier to work out because the pinouts were written inside on the PCB, not so for the Denso.
I Got excited as I thought that I would be able to use the Denso case for the Frankenso but the holes are different and the case is longer...never mind.

Nearly finished assembling the Frankenso, so next step will be a basic map, or tune as tuner studio called it.
There are 3S-GTE tunes for the Megasquirt on there website, so would I be able to load one of them into tuner studio and burn it to Frankenso.
Or is that completely stupid of me.

Thanks Blundar, for your comment, do you think that I should cut and fit a 36-1 somewhere and forget the existing sensors.
or replace the pickups with industrial pre signal conditioned ones?
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kb1gtt
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

12 tooth, spaced ?? relative to TDC? Also the teeth are ?? wide with ?? gap. Same questions for the CAM sensor.
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Roo-Barb
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

Tooth width =2.25mm
Tooth Gap=3.75mm
Tooth Pitch therefore = 6mm.
Got to confirm count but ~ 36 -2.

Cant find cam sensor so I will have to do a web search, as my son has just left for a holiday in Thailand,
and if I start stripping down the engine without him he will be a bit pissed off.

Cover and Harmonic Balance replaced without moving crank.
Cover and Harmonic Balance replaced without moving crank.
3S-GTE Crank Sensor - 4.jpg (348.53 KiB) Viewed 12407 times
TDC Last tooth before gap of 2
TDC Last tooth before gap of 2
3S-GTE Crank Sensor - 3.jpg (292.66 KiB) Viewed 12407 times
Showing VR Sensor/Pickup
Showing VR Sensor/Pickup
3S-GTE Crank Sensor - 2.jpg (282.02 KiB) Viewed 12407 times
Alignment re TDC
Alignment re TDC
3S-GTE Crank Sensor - 1.jpg (374.08 KiB) Viewed 12407 times
Roo-Barb
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

One Fellow says 32 teeth +1 long flat tooth.
But I am assuming by looking at the crank ring that he means 32 teeth not counting the 1 on each end of the flat spot which has 2 missing which = 36 teeth -2 or 34 and a gap of 2.
From Toyomods.
From Toyomods.
3S-GTE crank.jpg (53.23 KiB) Viewed 12403 times
And The Cam position sensor is only 1 metal flag that also passes a VR pickup.

Cam Sensor
Cam Sensor
3S-GTE Cam Position Sensor - 1.jpg (205.04 KiB) Viewed 12403 times
Hope this helps...
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kb1gtt
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

It appears you are saying this is a 36-4 wheel. The 36 is how many teeth it would have, the -4 is how many are missing to indicate the sync section. The 36 teeth wheel is often a chosen tooth count because of 360 degrees per rotation. Make for easier math, as every tooth is 10 degree's.
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Roo-Barb
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

My personal observation is that there are 34 pulses or active teeth coming within the flux path of the VR pickup and the flat section is lower or outside the flux therefore being 2 teeth missing, hence 36 or 10 degrees as you stated and 20 degrees of no trigger. 2 missing teeth.

I am unsure as to where blundar gets the 12 teeth from as I have only been able to find 36 -2.

The net is full of garbage suppositions being stated as fact, with some even going as far as fitting external 36 -1 & 36 -2 wheels to 3S-GTE's because they seem to not be able to count the existing teeth for some reason.

I do have a question that you are most qualified to answer.
Is it true that using a larger diameter wheel , thus higher surface speed, should improve low speed performance with a VR pickup?

I seem to see this as a common statement.

Thanks.
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kb1gtt
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

I just made a rough attempt at documenting this on the wiki. You're not the first or last to inquire about VR specifics. There are many parameters involved in making the VR properly detect the crank angle. Surface speed is definitely one of them, but so is the load resistor, air gap, and tooth dimensions. I think you'll get a good answer from the application note I posted at the below wiki link.

http://rusefi.com/wiki/index.php?title=Manual:Hardware_Trigger#VR_notes
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kb1gtt
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

I just made a spread sheet from a Honeywell app note. I have posted it's link here http://rusefi.com/wiki/index.php?title=Manual:Hardware_Trigger#VR_lower_level_details.2C_formulas.2C_app_notes.2C_etc

This PDF and app note should help convey how variations in your wheel and sensor will effect the signal produced by the VR sensor.
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Roo-Barb
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by Roo-Barb »

Thanks for all your hard work.

The Wiki is coming along well.

Another question now that we are on the track.

How about enclosed optical wheels or even a 360 ppr IP65 rotary encoder?

would they perform as well or better than the other 2?

I often use them in very harsh environments and they also can provide an index pulse, and often come with noise immune differential outputs.

mounting would appear difficult at first but as 360 PPR is very low res for an encoder there is no reason that they could not be put inside the timing case and driven from the belt.
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Re: 3S-FE soon to be 3S-GTE 1995 Rav4 2door

Post by kb1gtt »

Optical is very similar to Hall, both work well with the MAX9926 input circuit. You'll need to check if it needs a pull up or pull down resistor. We don't currently have any industrial optical decoders, I would expect that would be hard to physically mount, as well they are often cost a bit more. I have seen several applications where an OEM optical encoder was fitted. If you can get an OEM optical, that's often the best approach from a technical stand point.
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