Twinturbo120 said:

Okay, so value right now .10v with no TPS sensor connected. Greattttt wiring issue. I have already checked ground as suggested in other threads.

With the ign on I measured the following:
Green/Yellow = 4.78 volts
Brown/Red = -.08 volts (that's right,negative)
Yellow/Red = 4.32 volts

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Were you measuring relative to chassis ground or the black wire (ECU sensor Ground)?

G/Y is ECU sensor +5v. Seems a little low but it's all about where your measuring between since the measurement is the relative potential difference between two points.

BR/R is TPS output voltage.

Y/R is IPS. This signal has a pull-up to +5v inside the ECU and the TPS grounds it when the IPS closes.

The ECU measuring 0.1v when the TPS isn't connected isn't what I'd like to see but it's less that the 26% you were getting before.

With the TPS still off the TB but connected to the ECU what does DSMLink read?

steve said:

Were you measuring relative to chassis ground or the black wire (ECU sensor Ground)?

G/Y is ECU sensor +5v. Seems a little low but ti's all about where your measuring since the measurement is the relative potential difference between two points.

BR/R is TPS output voltage.

Y/R is IPS. This signal has a pull-up to +5v in the ECU and the TPS grounds it when the IPS closes.

The ECU measuring 0.1v when the TPS isn't connected isn't what I'd like to see but it's less that the 26% you were getting before. With the TPS still off the TB but connected to the ECU what does DSMLink read?

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I measured relative to chassis ground, no continuity. As it should be. I'll have to check at another time for the reading you asked for.

What are you thinking it is?

I'm thinking the negative value is just an artifact of the ECU ground being above the chassis ground and not a big deal. The original problem I'm not sure yet if it's mechanical or electrical.

I would be considering and inspecting the car's ground quality. Looking at your history I see you've had to do both the engine and harness in this car so there's a lot of non-standard problems to consider.

steve said:

I'm thinking the negative value is just an artifact of the ECU ground being above the chassis ground and not a big deal. The original problem I'm not sure yet if it's mechanical or electrical.

I would be considering and inspecting the car's ground quality. Looking at your history I see you've had to do both the engine and harness in this car so there's a lot of non-standard problems to consider.

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Welp, I did that. The issue will have to be the throttle body.

I have a junk 2G TB and it reads 0 on position and voltage. I can adjust it perfectly though to .63 volts reading 0 on the position which is what its suppose to be.

Can't say the same thing about the 1G N/T I have on the car.

I assume that the TPS removed from the TB plugged into the harness also does that. Which would point at something mechanical in how the same TPS on that NA TB is working.

steve said:

I assume that the TPS removed from the TB plugged into the harness also does that. Which would point at something mechanical in how the same TPS on that NA TB is working.

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I'll look more into it today after work. This is really starting to frustrate me.

I'll compare both TB's and see if their are any differences

Guys, I never got clarification on whether I should mess with my TPS adjustment or not.

Are my specs to out of wack?

Car has sat for a while and now that my semester is over I really wanna tune it properly but starting with idle.
Again, my TPS offset is set at 0 and on a 103% scale. I am able to get 0.63v and a full 5.00v when I push the gas pedal in fully to where link will tell me I go from 0% throttle position to a full 100% (if scaled to 100%, TPS volts is at .63v with throttle fully closed but only about 4.95v or so when gas pedal is fully depressed and throttle position only goes up to about 96%). This is ONLY with the car off.

Once I start the car, at idle, the TPS volts is at 0.65v and 5.00v with gas pedal fully depressed.

Since Steve said for us 2g guys, TPS adjustment should be based on the IPS switching point, my question is what point would that be when the throttle opens?

I'm running a 1g NT TB with an Evo 3 intake on my 2g DSM so therefore I am using a 2g TPS with my 1g NT TB.

This TB doesn't use an SAS screw that I'm aware of. Instead, it has an idle position switch which is the screw that comes in contact with the lever that dictates how far the throttle plate cracks open. Should this be messed with at all? I do feel like I can sense a little bit of throttle stick when I first push the gas pedal.

When I set up 1g throttle bodies, while there is a spec for how to set the idle switch/throttle body stop (@steve has posted about it before), I only adjust it to make sure the throttle body doesn't stick. I set it in place, lock it down, and then open the throttle body by hand and let it slam shut (to simulate the most force on the throttle body plate). This is done on a bench for me, but you can replicate it in the car by taking off the throttle cable and moving the cable bracket by hand. Then try to open the throttle plate using the bracket by hand. If there is any sticking, I screw the adjuster in a bit to open the plate a tiny bit more and repeat. You don't want to have the plate open any more than necessary so small adjustments are important. Once you get to the point where it does not stick at all by hand, lock it down good and then check again. Then reattach the throttle cable and see if it feels ok with your foot.

Then I run through link and check the voltages for the TPS and adjust accordingly. I aim to get .63v on the low end and then whatever 4.9x I can get at WOT.

Two things I do is make sure your floor mat isn't under the gas pedal preventing it from going the whole way down and, if possible, get a second person to verify that once your pedal is down to the floor that they can't move the throttle cable bracket any more by hand to open it up. If the person can't open the throttle any more, you should be good to go. If they can, then you have to investigate why your pedal isn't doing its job.

I ignore the IPS comment when using a 1g throttle body since you don't have the SAS screw.

snowborder714 said:

When I set up 1g throttle bodies, while there is a spec for how to set the idle switch/throttle body stop (@steve has posted about it before), I only adjust it to make sure the throttle body doesn't stick. I set it in place, lock it down, and then open the throttle body by hand and let it slam shut (to simulate the most force on the throttle body plate). This is done on a bench for me, but you can replicate it in the car by taking off the throttle cable and moving the cable bracket by hand. Then try to open the throttle plate using the bracket by hand. If there is any sticking, I screw the adjuster in a bit to open the plate a tiny bit more and repeat. You don't want to have the plate open any more than necessary so small adjustments are important. Once you get to the point where it does not stick at all by hand, lock it down good and then check again. Then reattach the throttle cable and see if it feels ok with your foot.

Then I run through link and check the voltages for the TPS and adjust accordingly. I aim to get .63v on the low end and then whatever 4.9x I can get at WOT. Two things I do is make sure your floor mat isn't under the gas pedal preventing it from going the whole way down and, if possible, get a second person to verify that once your pedal is down to the floor that they can't move the throttle cable bracket any more by hand to open it up. If the person can't open the throttle any more, you should be good to go. If they can, then you have to investigate why your pedal isn't doing its job. I ignore the IPS comment when using a 1g throttle body since you don't have the SAS screw.

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Thank you snowboarder! Now my question is, just to clarify, is it not so critical anymore to get that idle position switch screw at that perfect spot?
I remember seeing many posts stating that it's a very critical adjustment and that is why the service manual states to not touch it. But maybe because I have a 2g, it isn't so critical.

Also, will I have to use the "simulate idle switch" feature on ecmlink? Or this only for people running a 1g tps?

Its built into the 2g TPS I believe Sol. You can always simulate so when it reads .63 it knows you are at idle, 0% throttle.

With regards to basic idling, the 1G IPS and the 2G stop screw provide the critical setting of how much air leaks past the butterfly when the throttle is closed. The less that does while not binding the more the BISS, FIAV, and ISC can have control over the bypass air.

It's my opinion that this is the most critical adjustment on the TB, too much and the car will never idle correctly. The ECU is much more flexible in comparison about when the throttle closed signal switches and the TPS voltages.

Hey guys, so a little bit of an update. I was finally able to work on my car after months of it sitting.

I initially did the adjustment of the idle switch/throttle body stop screw by first using a multimeter and checking for continuity when the throttle plate lever touches the idle stop screw. Well this was already happening so I backed out the screw more and more until I was no longer getting continuity. I then turned the screw in JUST barely until continuity was reached. So now, if I follow the manual's instructions, I should then turn 15/16 of a turn but some people say 1 and 1/4 turn. Either way, the point where continuity was reached was the exact point where my throttle sticking issue was so basically all the work got me to the exact point I started off with .

I then turned the screw until I didn't have the throttle sticking issue and this was alleviated before 1 and 1/4 turn or even 15/16 of a turn. Even if I did use the factory method, 1 and 1/4 of a turn caused my throttle position to go up to 2% or so and that tells me that the throttle plate is definitely too far open.

Anyway, the best I could manage once I got to the TPS was 0.63v at 0% throttle position with the car off. When I pressed the gas pedal all the way down, the highest I could get the TPS volts was 4.86v which is fine from my understand.

The problem is that the throttle position would only go to 97%! No matter what I tried! The only time I could get it to 100% is when the TPS went from 0.63v go like 0.70v and up. It's driving me absolutely nuts!

Should I not worry about getting to 100% throttle?? I though maybe my cable wasn't pulling the throttle plate far enough so I pushed the throttle lever by hand myself all the way back and saw on link that it was still registering only 97%. This tells me that my throttle plate is definitely fully open but only wants to say 97%.

Before I could make anymore progress, all of a sudden the TPS values kept changing (going lower) every time I pressed the gas pedal all the way down. At this point I realized my battery was sitting at 5 volts and I guess battery voltage has some affect on TPS values?

Anyway, this is where my progress stopped and now my battery is a dud and I can't even use link anymore

Have you played with TPS Offset/TPS Scale values in link to see if you can get it reading properly at both ends?

@snowborder714 , prior to this adjustment I did. TPS offset was untouched at 0 and moving TPS scale to 103% fixed the issue. But after reading this thread I thought maybe this was a bandage fix to a problem. I guess I just don't know if setting the scale to 103% is excessive or would give me problems. In the future, I want to get a remote tune and idk if this would be a problem that will be pointed out to me and be told that I need to fix it or not.

The idle setting is more important. The WOT setting can be any value that is 4.9ish. I would use the offset in link to set the 100% value. It may mess with the idle setting so be ready to offset it maybe to a -1 after that.

Marty, what do you mean by the "idle setting"?

You mean the 0.63v value?

Okay so basically then am I okay to set the offset to 103% or whatever that new value would be to get 100% at WOT for my throttle position? I mean obviously I know that if I had to set TPS scale to 116% or something then that's something that would definitely need to be fixed, but I'm assuming 3% or so shouldn't hurt.

Also, surprisingly, it does not mess with the idle setting (0.63v). Literally the only thing it seems to change is the throttle position value.

Yes that is what I meant. Sometimes it will goof with the lower offset, sometimes it won't. You should be good now. The ECU looks at that stop switch setting to idle down. On my1g cars, if the idle switch isn't a (1) then the car doesn't like to come down to a 900rpm idle. As soon as it see's that idle switch, they come to a nice idle instead of 1300 or so. I have played in link just to see what the reaction is. Set that 100% value and your ECU will not care.

Thank you sir! Next time I work on the car, I will report back. I really hope I get no issues now, although I have a feeling my ISC position will not be where I want it to be

Ah, dont worry yourself to death over it. Idk if I've ever worried about mine. I tune the car to what it likes since I don't have FIAV's anymore.

ishnish said:

Hey guys, so a little bit of an update. I was finally able to work on my car after months of it sitting. I initially did the adjustment of the idle switch/throttle body stop screw by first using a multimeter and checking for continuity when the throttle plate lever touches the idle stop screw. Well this was already happening so I backed out the screw more and more until I was no longer getting continuity. I then turned the screw in JUST barely until continuity was reached. So now, if I follow the manual's instructions, I should then turn 15/16 of a turn but some people say 1 and 1/4 turn. Either way, the point where continuity was reached was the exact point where my throttle sticking issue was so basically all the work got me to the exact point I started off with . I then turned the screw until I didn't have the throttle sticking issue and this was alleviated before 1 and 1/4 turn or even 15/16 of a turn. Even if I did use the factory method, 1 and 1/4 of a turn caused my throttle position to go up to 2% or so and that tells me that the throttle plate is definitely too far open. Anyway, the best I could manage once I got to the tps was 0.63v at 0% throttle position with the car off. When I pressed the gas pedal all the way down, the highest I could get the tps volts was 4.86v which is fine from my understand. The problem is that the throttle position would only go to 97%! No matter what I tried! The only time I could get it to 100% is when the tps went from 0.63 go like 0.70 and up. It's driving me absolutely nuts! Should I not worry about getting to 100% throttle?? I though maybe my cable wasn't pulling the throttle plate far enough so I pushed the throttle lever by hand myself all the way back and saw on link that it was still registering only 97%. This tells me that my throttle plate is definitely fully open but only wants to say 97%. Before I could anymore progress, all of a sudden the tps values kept changing (going lower) every time I pressed the gas pedal all the way down. At this point I realized my battery was sitting at 5 volts and I guess battery voltage has some affect on tps values? Anyway, this is where my progress stopped and now my battery is a dud and I can't even use link anymore

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Did you end up figuring out what the problem was (if there even was one)? I recently got Link and although I had adjusted my TPS perfectly to 0.63v way back using a multimeter, I am also only getting a maximum of 97% at WOT with everything adjusted by the book (including all 3 adjusting nuts in the cruise box). With the car off, the TPS reads 0.63 volts and 0% throttle, thus the idle switch value in ECM is logged as a constant 1 (1 meaning idle is active). If I start the car, suddenly the TPS value goes from 0.63v to 0.65 exactly like yours. Then it logs 1% throttle and the idle switch is now showing 0, which means the ECU thinks Im adding throttle manually. If I use the TPS Adjust helper it always wants to scale it to 103%, again like yours. This brings the maximum throttle value from 97% to 100%, although the fact remains that the ECU still sees a constant 1% throttle application.

Stock TB/Manifold/Cable 2G car. I am stumped.

Kryndon said:

Stock TB/Manifold/Cable 2G car. I am stumped.

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I bet if you set the TPS as the factory suggests and didn't simulate the IPS it would work fine with DSMLink.

steve said:

I bet if you set the TPS as the factory suggests and didn't simulate the IPS it would work fine with DSMLink.

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So what are you getting at?

Are you saying to just leave it be at 97% max throttle?

I am not simulating the idle position switch through Link (it's unchecked). I only have the first box checked (Enable idle switch operation). If I recall correctly the FSM stated to place a 0.15mm feeler gauge in between the throttle stop and the throttle itself while manually adjusting the TPS to find continuity.

Still doesn't explain why me and ishnish are getting a 0.02v jump on TPS voltage upon startup. I guess I'll re-check everything tomorrow and set the SAS/TPS again.

If your IPS was working correctly the voltage with the throttle closed or at WOT wouldn't matter much. Tom and Dave may have added more code that checks for absolute TPS values (or even scaled ones) than the one for clearing flooded engines but the factory code usually checks for the changes between readings. It wants to know if you just mashed the throttle or released it more than exactly where it is.

As for the change in voltage between running off battery and once the alternator kicks in, I'm guessing that the regulation of the +5v sensor power from the isn't very tight or you have added additional loads to it.

If you're not simulating the IPS I wonder how that small change in TPS voltage is causing you to change state on the logged idle switch.

The only other thing I can think of offhand is your throttle cable might be moving the throttle when running vs not.

Kryndon said:

Did you end up figuring out what the problem was (if there even was one)? I recently got Link and although I had adjusted my TPS perfectly to 0.63v way back using a multimeter, I am also only getting a maximum of 97% at WOT with everything adjusted by the book (including all 3 adjusting nuts in the cruise box). With the car off, the TPS reads 0.63 volts and 0% throttle, thus the idle switch value in ECM is logged as a constant 1 (1 meaning idle is active). If I start the car, suddenly the TPS value goes from 0.63v to 0.65 exactly like yours. Then it logs 1% throttle and the idle switch is now showing 0, which means the ECU thinks Im adding throttle manually. If I use the TPS Adjust helper it always wants to scale it to 103%, again like yours. This brings the maximum throttle value from 97% to 100%, although the fact remains that the ECU still sees a constant 1% throttle application.

Stock TB/Manifold/Cable 2G car. I am stumped.

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So sorry as I haven't been active on this forum whatsoever since I've been in the nursing program for the past almost year and a half.

I will definitely hunt down and check what I did because it's been so long that I don't remember!

Kryndon said:

So what are you getting at? Are you saying to just leave it be at 97% max throttle? I am not simulating the idle position switch through Link (it's unchecked). I only have the first box checked (Enable idle switch operation). If I recall correctly the FSM stated to place a 0.15mm feeler gauge inbetween the throttle stop and the throttle itself while manually adjusting the TPS to find continuity. Still doesn't explain why me and ishnish are getting a 0.02v jump on TPS voltage upon startup. I guess I'll re-check everything tomorrow and set the SAS/TPS again.

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Meh, don't worry about the voltage jump. Many people's cars do that including mine. It's only a problem when the IPS changes... which is your situation.

Like Steve said, set the TPS manually per the FSM and see if that helps. If it doesn't (it should) then maybe screw in the IPS a tiny bit so it doesn't activate the IPS inadvertently and redo your tps adjust.

Ideally you would always set the TPS manually per FSM.