Rolling stop shut of engine, more problems 2/7/09

[7thousandpiecesMGTE]

I'll second the comment about adjusting idle as there isn't any way to do it properly (idle is controlled through the idle control, not the throttlebody)

quick questions on this screw (I still I have much to learn):

A. why is it on the motor if it is not supposed to be used? Emergency situation, like if something breaks adjusting it will get you home or?

B. What if you have fucked with it not knowing you were not supposed to, what is the factory setting (where is it supposed to be)?

C. No matter what you do with the screw, is the computer supposed to adjust and reset the idle anyway (mine has stayed low after adjusting it down to 650rpms...)

Not trying to jack just adding to the conversation, OP might be curious to know the answers also...

 

[LordChase]

If i swap out the TPS and follow the TRSM will it come out them same? do i need to worry about base timing or anythign or just swappem calibrate it and done? 0.o

 

[Poodles]

The screw is a stop screw that is set from the factory so the throttle plate closes in a specific position.

Much like the screw in the AFM housing is tuned at the factory.

I'm unsure of how it should be adjusted, I'd make sure the throttle plate closed all the way without binding though...

 

[jdub]

Just to clarify something: There are 1 or 2 screws (depending on early/late model) on a 7M TB that can affect idle. One is to adjust the TB plate stop via the linkage on the side and is used to set the TPS in the proper position to sense IDL on/off. This is the most common reason you can get a code 51. As previously stated, if the ECU does not get an IDL on signal, it will not idle for crap.

The 2nd screw is found on '87-'88 and some '89 TB's. It is on top of the TB and is called a TB bypass screw....it allows air past the TB plate using a different path. On some Toyota engines, this is used to set idle...on the 7M it is not (as stated, the ISCV performs this function) and is set from the factory to the full closed position. It was removed on the later model TB's because folks kept messing with it.

 

[Poodles]

IIRC that screw is covered with a plug that can be drilled out (same as the AFM) on the later models, if I find the spare TB I have I'll check...

 

[jdub]

Poodles - You are correct, it is covered with a plug...at least the TB's that have not been screwed (no pun intended) with

 

[7thousandpiecesMGTE]

Just to clarify something: There are 1 or 2 screws (depending on early/late model) on a 7M TB that can affect idle. One is to adjust the TB plate stop via the linkage on the side and is used to set the TPS in the proper position to sense IDL on/off. This is the most common reason you can get a code 51. As previously stated, if the ECU does not get an IDL on signal, it will not idle for crap.

The 2nd screw is found on '87-'88 and some '89 TB's. It is on top of the TB and is called a TB bypass screw....it allows air past the TB plate using a different path. On some Toyota engines, this is used to set idle...on the 7M it is not (as stated, the ISCV performs this function) and is set from the factory to the full closed position. It was removed on the later model TB's because folks kept messing with it.

I'd be one of the folks they were pissed off at.... :biglaugh:

I appreciate the clarification, and will not mess with it again, except to return it to the closed position.

 

[LordChase]

Ok well i swapped my TPS today unfortunatly the past 2 days have been a nightmare for working on my supra. Really need some help and suggestions as i am going to try again on monday. I swapped the TPS and my friend from toyota adjusted it but when i attempted to drive it i would get to 1750rpms and it would just cut all power and resume idle. i found out i had apparently broke the bottom bolt to SEE PIC not sure what it is called.

so when i go back monday i have to take off manifold and drill it out : / was my fault my guess is i cross threaded it. was very hard to get on for me atleast. anyway my car is throwing code 41 now for the TPS the one i had looked in good condition and came off a low mile car i have. i know that it couls be bad any 20yr old part can easily die but i need a list of options or things i can check to get my car running. before i swapped TPS's i could drive fine just had no boost. figured out it was due to the TPS. Swapped TPS in worse condition than when i started. When i go back monday i want to be prepared and get the job done if i know all my possible trouble areas i can knock them out. since i am getting code 41 i will start there any idea on how to fix it? need your input guys i have never boosted after my rebuild over a year ago so it is getting frusturating.