HI.

Looking for some technical information on the Lambda sensor unit, for 185 & 205 , single wire & 4 wire.

The voltage over mixture ratio is what I am looking for, and the voltage at 14.7 reference would be good etc.

The stock unit on the 185 has been causing problems, only noticeably when running the denso ecu.

Recently, I could get denso ecu light to come on, as soon as the smallest amount of boost was applied, and yes, I had to try this on a cold engine, but limited the boost to a few psi.
Every time over 30 second period light on, sometimes sooner.

The slow decline in the function of the lambda has led me to using the wideband, via the lm1 control box, using analogue 1 for input into the denso, the MS has been running from the wide band, thus not showing the fault up, until the Knock sensor output started to change.

As this problem accrued, I first thought it to be a problem with the knock circuit construction used for the MS, but with further inspection, I realised these problems.

I have managed to coble together another knock sensor, which seems to run both MS & denso, but don’t wish to spend out on a o2 sensor from Toyota, specially when its not used that often.

I have a 4 wire, but not sure whether it works 100 % correctly, with out the values over voltage I have nothing to test it to.

Jon

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Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.

Jon, I have not measured the voltage directly but I would imagine that from a narrowband O2 sensor the output voltage at 14.7:1 would be 500mV.

I would imagine the voltage to be 0-1V, with a very rapid change in output voltage about the central point of 14.7:1.

I know you probably know that lot already, but that's all the info I have!

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

Thank Kris.

I knew I would get a answer here of sorts, have tried various ranges, still can't reach 14.7 on a run, got it from 13.1 to low 14.2 now, fuel is much better, getting more than a 100 miles per 30 quid of fuel.

Taking this time to upgrade the ms, fitting a 3 bar mapsenor, so i can get past the 21 psi limit.

thanks again

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Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.

Jon - that's still quite a lot of fuel per 100 miles!

Does the MS have the capability for fuel overrun cut off/deceleration cut off?

Are you using feedback from the O2 sensor to correct the fuelling?

Were you trying to map the car to 21psi on a 2 bar map sensor?

_________________
Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

Hi Kris.

On the MS I had a internal map sensor rated at 250 kpa - 1 atmosphere = 22 psi limit approx, you know what i mean.

Just wired up a gm 3 bar, so have to re do the ve tables again ..

The MS gave good fuel, around 25 mpg, with light use far better than the denso ever did.

Was only the problem with knock sensor system that made me switch over to the denso, after doing this, I get error codes on denso, this was 02 & knock, knock sorted now, o2 via the wideband on an1

The denso is the get me home unit, it amazes me; I want to hack it for complete control.

I had to go though all the systems on the gt4, this its self takes time, as I have 2 complete ecu’s to check out , a mobile lab.

Took this time to update the ms firmware, and install 3 bar map sensor, this will increase the working limit to 28 psi, also further improvement to the dizzy inputs, and further air temps sensors modifications etc, always something else to try out.

Hopefully I will get out this afternoon; it always takes longer than you give it, it’s the calibration that’s timely on the bench, before any tuning time can take place.

I data log every time I use the car, but recently I have stopped reviewing the logs, as time has been short, until this.

Does the MS have the capability for fuel overrun cut off/deceleration cut off?

Answer=Yes, the MS has full control over this ,the stock denso barrel washes compared to the ms, I have done many tests on decel/overrun, from na to boosted run etc.

You need fuel on over run / deceleration for cooling, etc, but linking temps to a value bin allows varying degrees of this as and when required, the denso waits 3 seconds before running its routine, does not sound much but on a few thousand miles starts to add up.

The ms will run its routine down to the 3rd engine cycle on over run/deceleration before implementing it routine, a balance of cooling to wash out has to be met.


Are you using feedback from the O2 sensor to correct the fuelling?
Answer = Yes Using wideband, have two outputs, 1 narrow band analogue 1, 1 wideband analogue 2. the ms runs with both, the denso on an1.

The MS can be set to enter closed loop at idle, it does not need to run in this mode, as the ve tables allow 14.7 to be maintained, I run closed loop on events that last longer than 15 seconds on constant tps feedback as well as other inputs.

For tuning I turn off all o2 feed back & routines, start the table tuning, once happy, turn 02 on and its all working, the ms has a little of everything available, just needs to grow in size a few times.

the denso without 02 will run, but once the internal map area limit has been breached, with out feed back from o2 it will continue to run very rich, by resetting the denso, using a different o2 sensor the denso will learn, but only to a point.

On the ms I use auto tune with the wideband, this then reworks the tables from what I have, to presets for what I want, go for a drive, after that, I run vexit for new table to be generated, then burn the table to rom, & save to drive, then start again.

the ms is great if you load new tables for what you have in mind, so town driving map1, motor way map2, flat-out map3.

Preparing for a turbo upgrade shortly, hopefully slide some new pistons in, and away we go for another 3000 miles.

My original aim was to hit 300 bhp using the stock bottom end, then stop at that, but I can’t stop, i have max 185 & 205 injectors to 99% with increased fuel rail pressure too, i am shortly going to try a pwm dc to dc converter, giving fuel pump power full control from 6 volts to 20 volts, should increase fuel pressure and flow a little more.


Ok its time for me to head out to install some new bits, and some running repairs to the 4 will hopefully know more soon of improvements


DJ

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Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.

Jon - interesting stuff.

I did not appreciate that a little fuel on decel will help reduce temps. This I suppose will be at the expense of mpg.

I would love to see the stock ECU base maps and the start up maps etc, this would be a terrific starting point when installing a new ECU!

Dennis Heath has some maps available on his website but the loading vs fuel/ignition is difficult to interpret.

So you have swapped from the 430cc 185 injectors to the 540cc 205 injectors?

Next stop I suppose is the SARD 850cc?

Nice idea with the PWM and voltage control over the stock pump. Have you considered the popular Walboro pump "upgrade"?

_________________
Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

Hi Kris.

I have a fuel pump that i will use, before going the route of fitting. Need to fit a swirl pot, as i don't trust the stock fuel tank for uninterrupted fuel supply even with its bowl around intake pipe on the pump.

Fuel tanks containing fuel under a 1/3, can under cornering, heavy braking etc, causes fluctuations in fuel supply, normally not a problem, but with modified stuff, attention to detail is necessary otherwise the engine get’s it.

The PWM fuel control system, simple and works, giving for improved fuel supply &, pressure, with control, the stock fuel regulator is old school design, time for 21st century design.

I will be using the ecu to control the rate of flow, , an earlier mess around with some injector for boost control, lead me onto this, using regulation via electrically controlled valves will be used to restrict the return from the fuel rail, a fuel rail pressure sensor for feed back completes the process.

At the moment I have just voltage/current controller, just simples increases the supply voltage to a preset level, the ms output for water injection is used for the control. Various outputs ca be assigned to this from the MS, building the required control board that allows a smooth control over a range is required

I found best result using fuel rail pressure around 58 psi, the stock pump works well at 16.5 volts, gives about 25% increase, maybe not idea for long duration, not burnt one out yet.

DC/DC inverter has had a few problems, mainly from low battery voltage, going for a smaller, lighter battery does have penalties, as when the electrical system is under high load, say with headlamps, heater blower, wiper, etc the voltage starts to fall below 13.0v this causes the inverter to work harder to maintain the 16.5volts, under load to supply fuel pump, I found fitting larger tank capacitors as well as lower impedance Fets helped to correct this.

The increase in the fuel rail pressure allows for a higher injector flow, something like 25% approximately +- a little, the 440cc seem to achieve 550cc the 550’s achieve close to 687cc, the ms injector times without mod 12.1ms now down to 8.7ms maintaining the same mixture level at idle, this seems to concur though the range.

Links to Dennis Heath would be handy.

I spent an evening working out the gt4 map sensor, plotting voltage over pressure, then inputting into excel, great months later gary165 sends a link with all this ready done. What a waste of my time.

Thing is I don’t have time to surf and build, shame as a number of times would have saved loads of my time.

jon

_________________
Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.

Should be the same for all narrowband one would imagine as most wideband's don't offer a programmable narrowband output

Hope that helps

Thanks steve.

Maybe i have read to much, but certain makes of o2 have varring degrees of voltage at 14.7

the Z3s (w/ Bosch O2 sensors) are 0-1v with 0.9-1v being rich (12.5:1ish AFR) and 0.0v being very lean. 0.45v is 14.7:1 AFR.

Siemens O2 sensors work opposite the Bosch sensors in that a low voltage signal is rich and a high voltage signal is lean

I wanted to find out what the stock single wire was set at.



the active window on the right is the programing tool for the lm1, so i can use the an1 for the denso


yet again thanks for post, will set it to the graph and go for a drive.

jon

_________________
Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.

can 100% confirm that 0.00v is lean reading and .9V is rich as heck

When I cold start mine the narrowband monitor runs from 0 to .88V as the sensor warms up and the mixture richens up on choke

in normal cruise operation I see wild variations between approx .3 and .7 V as the ECU Closed loops

with the loud pedal firmly depressed I regularly see 0.8V corresponding to a rough guestimate of 12:1

On overrun I tend to see an istant fuel cut with AFR decaying to 0.00-0.001V over 2 secs

Stevo posted the graph I was going to, so alls I'll add is to the above. It helps reduce the piston crown temps in a similar way to squirting oil on the bottom of the pistons. In addition to spitting flames and poorer mpg, it can eventually lead to borewash.

An option best left switchable for serious prolonged heavy boosting rather than everytime the car is allowed to use WOT.

Great one, cheers Guys.

A little tweak on the values, it now goes to the button, I forgot to add the wide band is at the bottom of the down pipe, cause a little offset maybe, but it now cruses at 14.7 again.

I have been though a few logs, last week it spent pretty much all its time running rich.

The gm map sensor change over did not go to well, done something wrong some where, it will run only if I select tps over map, before it ran at 50/50.

Further more expanding the kpa levels on the ve tables was one thing, but the ignition table has now been compromised as the changes in some of the kpa / ign bins are now made up, I tried to guest-a-mated either way, but now they are untested values.

What can I do about this, surely there’s some software somewhere that can calculate this out for me, or is it back to burning fuel, road testing again.

I think oil spray cooling is ok, does cause increase in oil temps, the use of chucking fuel down to cool works, both have side affects.

My health will improve once some forged pistons have been fitted, I can stop worrying about failure every time its road dyno time .

_________________
Black UK 96 205 shed with heater full on telemetry.

project six million dollar 185, faster, stronger, lighter than before.