443 replies to this topic

[Scuffers]

you either have a wiring issue or the ECU has some bug in it.

 

no way can a temp sender do this, ignoring it's not following it's spec curve, they just can't move that fast.

 

remeber, so far as the ECU goes, it's just a variable resistor to ground (same as any thermistor) 

[CHILL Gone DUTCH]

There is somthing going on the lambda sensors at the same time

 

 

As seen here

[Scuffers]

that will be the effect of the fueling changes due to the temp sender

 

trace the short and long term trims

Edited by Scuffers, 25 June 2014 - 07:05 AM.

[CHILL Gone DUTCH]

 

Here's a thought, is there a trigger coolant temp that starts measuring inlet temperatures? Before that the car will be running on a high fuel start map anyway.

No link with the timing of when the second lambda switches off the heater circuit? No real idea of sc setups, but the 10min timing sounds similar to the changeover point for the lambda circuit.

 

 

best explanation so far

[CHILL Gone DUTCH]

that will be the effect of the fueling changes due to the temp sender

 

trace the short and long term trims

 

give me a sec

[CHILL Gone DUTCH]

[Scuffers]

yup, that's the effect of the fueling changes from the jump in AIT readings, ie, the effect, not the cause.

 

 

[CHILL Gone DUTCH]

what ever is happening it has somthing to do with everything getting up to temp maybe the voltage for the Tmap is getting a signal voltage from somthing else

[Scuffers]

well, the TMAP is a plain and simple thermistor, so unless its got it's wiring crossed on the way to the ECU, I doubt it.

 

it's more likely that it's characteristics (resistance wise) are outside what the ECU is expecting? as in at a specific temp, it's resistance falls to a point where the ECU pull up/down is overcome?

 

if this is the case, it will always happen at the same temp

 

the alternative is that the 5V ref that's used in the ECU is being shared by ANO sensor and that's corrupting it, although usually when this happens, the voltage drops...

 

the fact it's occurring on more than 1 car points to an ECU problem either in compatibility with the sensor, or the calibration of the sensor is up the creek, I would go for the latter but your log shows it as a voltage, which if right (as in that's what the actual sensor is reading) points at compatability issues.

 

do we have the spec of the std NA AIT to compare with the TMAF one?

 

 

 

 

 

[CHILL Gone DUTCH]

If you want I can ask peter what is happening ? Saves us speculating

[techieboy]

If you want I can ask peter what is happening ?

 

Me thinks that's the best route to take.

[slindborg]

Given the hardware was never really designed to run with 50+ iats so it wouldn't be a huge surprise if the pull up was too strong for the thermister at that point. That or Mr Peters code isn't coping, or its the oem diagnostic code coming to spoil the party by assuming the sensor is shorted and applying a default value

[siztenboots]

the rise time on the sensor is probably quite long, you really need a k-thermocouple in there for fast response

 

 

quick look at the specs for 2.5bar tmap , t₆₃ = 10 s , resistance at 20°C = 2.5kOhm

 

 

so back on page 3 , I posted the above which must have been missed, its been a long while, but iirc the rise time for the sensor to reach 63% of its new value is 10 seconds , or Loge , the deviation error decreases in a non linear way with time.

[siztenboots]

actually the memory was not so bad

 

http://www.ohizumi-m...chnote1.html#a7

7. Thermal time constant

A thermal time constant （γ） is defined to be a constant indicating the degree of thermal responsiveness of a thermistor. No thermistor operation can be free of a time lag because the thermistor’s every operation is a thermal phenomenon. Thermal time constant （γ） is the period of time necessary for a thermistor temperature to change by 63.2% when wattage is applied to the thermistor and an abrupt change is made to it from a heat equilibrium state to a zero load state.

[CHILL Gone DUTCH]

actually the memory was not so bad   http://www.ohizumi-m...chnote1.html#a7 7. Thermal time constant A thermal time constant γ is defined to be a constant indicating the degree of thermal responsiveness of a thermistor. No thermistor operation can be free of a time lag because the thermistors every operation is a thermal phenomenon. Thermal time constant γ is the period of time necessary for a thermistor temperature to change by 63.2% when wattage is applied to the thermistor and an abrupt change is made to it from a heat equilibrium state to a zero load state.

Can you translate that steve Thanks

[Scuffers]

 

the rise time on the sensor is probably quite long, you really need a k-thermocouple in there for fast response

 

 

quick look at the specs for 2.5bar tmap , t₆₃ = 10 s , resistance at 20°C = 2.5kOhm

 

 

so back on page 3 , I posted the above which must have been missed, its been a long while, but iirc the rise time for the sensor to reach 63% of its new value is 10 seconds , or Loge , the deviation error decreases in a non linear way with time.

 

so the next question is what's the spec of the std IAT for the ECU?

 

bit of a worry that nobody picked this up when deciding to use this TMAP...

[slindborg]

I have a spit open Z22SE ecu should we need to know the pull ups

[CHILL Gone DUTCH]

 

the rise time on the sensor is probably quite long, you really need a k-thermocouple in there for fast response

 
 

quick look at the specs for 2.5bar tmap , t₆₃ = 10 s , resistance at 20°C = 2.5kOhm

 
 
so back on page 3 , I posted the above which must have been missed, its been a long while, but iirc the rise time for the sensor to reach 63% of its new value is 10 seconds , or Loge , the deviation error decreases in a non linear way with time.
 

so the next question is what's the spec of the std IAT for the ECU?
 
bit of a worry that nobody picked this up when deciding to use this TMAP...

I might have some logs before Tmap to look at

[slindborg]

 

actually the memory was not so bad   http://www.ohizumi-m...chnote1.html#a7 7. Thermal time constant A thermal time constant γ is defined to be a constant indicating the degree of thermal responsiveness of a thermistor. No thermistor operation can be free of a time lag because the thermistors every operation is a thermal phenomenon. Thermal time constant γ is the period of time necessary for a thermistor temperature to change by 63.2% when wattage is applied to the thermistor and an abrupt change is made to it from a heat equilibrium state to a zero load state.

Can you translate that steve Thanks

 

 

 

if your IAT is reading 20Degrees and the air temp changes to 30Degrees, it will take 10seconds for the sensor to read 26degrees when the air temp is still 30 degrees.

[Bargi]

 

the rise time on the sensor is probably quite long, you really need a k-thermocouple in there for fast response

   

quick look at the specs for 2.5bar tmap , t63 = 10 s , resistance at 20°C = 2.5kOhm

    so back on page 3 , I posted the above which must have been missed, its been a long while, but iirc the rise time for the sensor to reach 63% of its new value is 10 seconds , or Loge , the deviation error decreases in a non linear way with time.  

so the next question is what's the spec of the std IAT for the ECU?   bit of a worry that nobody picked this up when deciding to use this TMAP...

Easy tiger, lots of speculation and assumptions at the moment, I've mentioned it in an email to Peter. Matt echoed the comments you have about the OBDTuner and to me at the National and they sound valid from a tunning point of view. Drop Peter and email, he's a very accommodating guy, quick to respond and it'll get us to an answer quicker and perhaps some insight. He rarely visits forums much and so seems to get thus mystery man persona. I met Peter at Zandvoort last year and chewed his ear off for over and hour about him and and his software. Really good guy with a genuine passion in the VX/Speedster. Sometimes meeting people outside of a forum gives you a better insight into the person.