Fuel Trimming Device for 90 Series Petrol Engines.

[Toopy Member Find all posts View Profile Close Toopy]

why not just source an ecu from a Toyota Colorado (prado) 3.4l from the UK

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

........

Glen: what resources do you have on the motor? Going through m fsm, I can't find any specifications on the knock sensors to measure the readings. I've been tempted to run a multimeter plugged into the diagnostic port or straight off the ecu knock sensor inputs to measure the voltage, but is kind of pointless until I know what I'm looking for or how to reliably cause a knock to measure the readings. If i can find that out, I can easily replicate that signal into th ecu and measure the timing to see exactly how it works.

Bushoz: really keen to get some feedback from you. How you addressed oUr concerns. If not, I'd be keen to help develop it further.

Yes that's the problem, what kind of signal do we expect. A small voltmeter semi-permanently wired onto the inputs could show it (such as http://ecx.images-amazon.com/images/...dL._SX300_.jpg), and just drive as normal, but being able to see the changes just at the right time would be hard.

[Toopy Member Find all posts View Profile Close Toopy]

The cartester software and homemade cable from here http://www.pradopoint.com/showthread...I-TDCL-vs-MOBD will record all the timing info, and I thought the knock sensors just went to gnd as isnt that the problem when the wiring goes

i used this link from thread
http://www.mr2oc.com/showthread.php?t=520850

by the wiring diagram they have 1input and run to gnd

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Knock sensors are essentially a microphone. Yes they have a ground but the other is not inputs, they are an output. An varying voltage created by the movement of a coil. Much like a speaker, but instead of putting power in, it creates a small amount of electricity and it gets sent out to the ECU. That's also why the output wire is shielded.

Cartester software doesn't show knock triggers.

Glen, the signal will be in millivolts and I'm yet to determine if its a constant output or if the knock sensor does the frequency filtering. If its a frequency trigger it'll be harder to trigger as the led flashlight would need to be a frequency counter if it works on a voltage trigger then it'll be easier but less reliable.

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

I'm tempted to wire up my multimeter as it'll measure both AC voltage and Hz at the same time. I can also connect my phone via Bluetooth to it and use my phone as a data logger for it. But still come back to the same dilemma... How do I make it knock? In the past when I was doing some troubleshooting and replacing my timing belt, I did find myself with a timing light and a hammer whacking the block in various places but could never trigger it. I'd love to say faulty sensors... But I know they are good from the few times I have caused it to knock and I threw a code and the engine tripped over its front wheels as its timing went retarded to all hell lol. Towing a car and trailer up a hill suddenly got interesting as I thought I was going to need another tow car with another trailer for the Do.

[Toopy Member Find all posts View Profile Close Toopy]

Knock sensors are essentially a microphone. Yes they have a ground but the other is not inputs, they are an output. An varying voltage created by the movement of a coil. Much like a speaker, but instead of putting power in, it creates a small amount of electricity and it gets sent out to the ECU. That's also why the output wire is shielded.

Cartester software doesn't show knock triggers.

Glen, the signal will be in millivolts and I'm yet to determine if its a constant output or if the knock sensor does the frequency filtering. If its a frequency trigger it'll be harder to trigger as the led flashlight would need to be a frequency counter if it works on a voltage trigger then it'll be easier but less reliable.

The cartester does show knock sensors
but only in a threshold fasion

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Hmm... Thanks toopy. That's actually pretty close to what I'm chasing. I'll check it out again. See if there is a digital trigger in the code that'll revert the yes back to a know when it stops knocking.

[Ozbush Junior Member Find all posts View Profile Close Ozbush]

Hi Guys
Sorry for my absence.
Please take a look at this video.
He has been running my prototype Mapper for quite sometime.

https://www.youtube.com/watch?v=qtZuSKqvvqM

The question of fuel trimming too low is always can be dangerous but you just make sure test the condition enough then you know what the setting is good for you.

Yeah the 90 series petrol 3.4l is run quite rich for many people I met.

Normally they are all quite happy with -8% to -5% lean setting.

Some guy even tried to run -15% and found cars are very struggling.

I warned him if you make it too lean it will burn out the exhaust valves but he didn't care and his car is still going ok as he says every week.

I think his car was going very rich before and even -10% setting he is just within the right stochiometry.
He is quite happy now

I have sent out over 10 mappers for 3.4L 90 Prado now.

So far no drama. it is not very critical sensitive for lean settings, your car is not going to blow up straight away.

I have Exhaust Gas Temperature gauge if anyone wants to try out. Let me know.

Cheers
Ozbush

[mal58 Junior Member Find all posts View Profile Close mal58]

Hi Guys,
Interesting discussion and video.

Now to go back a bit, according to the "Gregorys" manual it shows that there are two versions of electrical engine management systems for the V6 90 series prado. (if you have the manual, pages 116 and 117). This shows (page 117), oxygen sensor - where fitted.

My point is, if you could use the Oxygen sensor as part of the memory mapper, you would be able to have a feedback path to give better control.

Cheers,
Mal

[Toopy Member Find all posts View Profile Close Toopy]

Hmm... Thanks toopy. That's actually pretty close to what I'm chasing. I'll check it out again. See if there is a digital trigger in the code that'll revert the yes back to a know when it stops knocking.

In cartester if you select bytes protocol from the type menu it shows the raw values coming in. The knock sensor value shows 0, but I haven't forced a knock when running. I'd say unfortunately that the real values are being interpret by the ecu and the converted knock value only output once the threshold is exceeded. only testing will tell.

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

hehe... I think so mate. unfortunately... not something I'm keen to test on a regular basis.

Glen:... little bit of a jackpot... http://www.parksoffroad.com/tacomamo...e/cip0325p.pdf

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Great find Ranj! According to that document we might assume the sensors working range is between 1,700 and 5,400 rpm - much better than I read elsewhere.

I could easily make knocking occur, 91 octane fuel with 98 map, big hill...... but yeah wouldn't want to do it more than once.

We should probably follow this up in a new thread