WOT TPS %
- Thread starter MDCmotorsports
- Start date
You could probably take measurements using this:
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_101.html
Throttle valve fully opened position (VTA -E2 termanials): 3.5 - 10.3 kOhms
http://www.cygnusx1.net/supra/library/TSRM/fi/FI_101.html
Throttle valve fully opened position (VTA -E2 termanials): 3.5 - 10.3 kOhms
TSRM states 4.0-5.0 volts.
You have to be careful with the feedback. You can be in open loop, heavy throttle, and not WOT.
You have to be careful with the feedback. You can be in open loop, heavy throttle, and not WOT.
Nick M said:
agree 100%. i know of a few motors that have been lost because of this. 1/2 throttle so the ecu is trying to maintain 14.7:1 and boosting 18psi. not pretty.
wait- you say open loop. i guess you meant closed loop. so as of now i agree 99%
It isn't the primary sensor for injector duration, but it is the primary for WOT.jetjock said:
That is a good point though. Injection is mostly dependent on airflow and rpm, and the TPS is there to let the ECU know your intentions.
What is the voltage signal at 100%wot from the tps supposed to be? I thought it is 4.5 volts but mine is only reading 3.4 volts at wot and .4 volts at closed. Is my sensor messed up? :icon_conf
jetjock said:
i dont see what is to decide?
i just see you saying it isnt and leaving it at that. please post your side.
either way, its a moot point for me. im either low throttle (<15%) or i'm letting 'er eat with the pedal thru the floor.
like i said earlier, lots of troubles can happen at mid throttle points.
edit: i see now where you posted in the beginning. sorry i missed that. now im super confused. you say throttle position of 60-70% and then you say tps isnt the primary input?
I think I see where JJ is going because you can unplug the TPS and drive your car with no issues other than high idle.
What is controlling it at that point?
What is controlling it at that point?
Ok here's another curve ball:
-When cruizing on the hwy, no matter the rpm, the AFR is 14.6-15.2
-When boosting, the AFR instantly jumps to 12.1 as soon as it hits 1psi. As the rpms climb and the AFR goes all the way to 10.1 and at redilne (10psi) the meter goes off the chart and reads "Rich"
-The idle AFR is any where from 16.1-19.1. AFM reading 26~28hz. 750rpms
-If I come off of a constant throttle (no boost, no heavy TPS%), rpm, speed (as in on the hwy or doing 30mph) and come to a stop light, the AFR goes straight to "LEAN" on the display, and the idle goes to 1200. Then the display starts running (fast mind you) towards the rich scale. 13,12,11,10,9 "RICH". Then the car dies.
Any body care to share whats going on here?
-When cruizing on the hwy, no matter the rpm, the AFR is 14.6-15.2
-When boosting, the AFR instantly jumps to 12.1 as soon as it hits 1psi. As the rpms climb and the AFR goes all the way to 10.1 and at redilne (10psi) the meter goes off the chart and reads "Rich"
-The idle AFR is any where from 16.1-19.1. AFM reading 26~28hz. 750rpms
-If I come off of a constant throttle (no boost, no heavy TPS%), rpm, speed (as in on the hwy or doing 30mph) and come to a stop light, the AFR goes straight to "LEAN" on the display, and the idle goes to 1200. Then the display starts running (fast mind you) towards the rich scale. 13,12,11,10,9 "RICH". Then the car dies.
Any body care to share whats going on here?
It is supposed to do that.MDCmotorsports said:
When crusing, you will be in closed loop most of the time, when the catalyst is up to operating temps. 14.7:1 is not optimum for the engine, but for the cat. So feedback is done to insure you do not pollute.
If you open the throttle, or go up a hill, load on the engine increases, so injection duration is increased.
Your idle AFR does look lean. DTC's will tell you if that is the case.
When you deccelerate, fuel is cut. But it is restored at a certain point to prevent stalling. You should check your DTC's if you stall.
When you open the throttle, airflow is increased into the engine, so injection is increased. The airflow meter and RPM are primary inputs for injection duration. TPS is to let the ECU know the drivers intentions.
Jet:
The car is not stock. Its got the lex afm with 550's, no emissions at all. Upgraded fuel pump, system, etc etc.
No AC either.
Come to think of it, if Im looking at the upper thermostat manifold with all the sensors on it, there is a big sensor right in the middle of the manifold, green in color, two wires. It looks a little shabby.... What does this sensor feed? ECU or gauge?
The car is not stock. Its got the lex afm with 550's, no emissions at all. Upgraded fuel pump, system, etc etc.
No AC either.
Come to think of it, if Im looking at the upper thermostat manifold with all the sensors on it, there is a big sensor right in the middle of the manifold, green in color, two wires. It looks a little shabby.... What does this sensor feed? ECU or gauge?
Diagnostic Trouble Codes. A term more commonly used in OBDII systems but still valid here. What we call codes. Since Nick is a former factory tech he uses the correct nomenclature. Can't fault him for that. Or did you want to know what codes could be set?
That is right JJ. WOT is Wide Open Throttle. I know you know what it means. I think you were under the impression I was refering to when the ECU goes to full duty cycles. I am not. WOT is when the pedal has been put to the floor, and the cable pulls the throttle plate wide open.
DTC is a term regulated by Congress. I think it is one thing they have done correctly, was standardized automotive terms, in addition to the emissions monitoring that was put in place with OBD level II. That is why I use it.
ECU, ECM, EECM, etc, were all made to be called PCM, for powertrain control module, for another example.
And JJ is right about the OBD I not being as reliable OBD II can even recognize a "lazy" oxygen sensor, compared to an actual lean engine. But it is still worth checking, in my experience.
And MDC, since you have the Lex, and different injectors than what the computer thinks, all bets are off. Reg's paige is correct in a way. But I have read about many Lex's that just don't run right with the same elctronics, and a switch back to the correct meter corrects their problem. That is why the SAFC and Eman and others are used.
It's all good Nick. I figured it we were on the same page at some point. Yeah, I use PCM on other forums but stick with what people know here. And I wish our cars were OBD-II, it'd make things a whole lot simpler.
Fwiw my car has the Lex and 550s and runs perfect. In all fairness it took a while to get it there though and gas analysis ahead of the cat was invaluble in doing it. I feel that's what it really takes to get it right.
Fwiw my car has the Lex and 550s and runs perfect. In all fairness it took a while to get it there though and gas analysis ahead of the cat was invaluble in doing it. I feel that's what it really takes to get it right.
I would settle for sequential injection, another OBD II requirement. MDC, a tool we used at the dealer is the one JJ mentioned, the gas analyzer. They are 4 or 5 gas. And the 4 works just fine. It tells you what is really going on inside the combustion chamber. It is an expensive toy, but an invaluable diagnostic tool for drivability and emission repair.
But I think your issue is with trimming the Lex signal with SAFC, Eman or whatever is used. How fast does it go rich? In less than a second?
But I think your issue is with trimming the Lex signal with SAFC, Eman or whatever is used. How fast does it go rich? In less than a second?
Nick M said:
Nick - at what time? Under boost or my wierd throttle => idle problem?
Under boost it is gradual with the rpm and boost. From WOT @ 1psi it climbs from 13 then to 12 to 11, to 10 to "RICH" (redline @ 10psi).
Under decel to idle, as soon as you let off the throttle it goes to display "Lean", the RPMs go to 1200 (pauses for 1 -2 second), and INSTANTLY the RPMS struggle and the meter says "Rich". Poof car dies.
term confusion here:
WOT = wide open throttle, i.e. throttle plate open 100%
OPEN loop = no more O2 sensor feedback
sounds more like the orig. q should have been "when does the ECU go open loop?"
EDIT: forgive me, it was early....
WOT = wide open throttle, i.e. throttle plate open 100%
OPEN loop = no more O2 sensor feedback
sounds more like the orig. q should have been "when does the ECU go open loop?"
EDIT: forgive me, it was early....
Last edited:
^ So true DR. J
Ask the wrong question, get the wrong answer.
So when does the ECU go into open loop?
Ask the wrong question, get the wrong answer.
So when does the ECU go into open loop?