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Thread: Throttle Position Sensor settings?

  1. #1
    Advanced Tuner coachcrow56's Avatar
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    Throttle Position Sensor settings?

    Can I use HPTuners scanner to adjust the settings for my Throttle Position Sensor??

    Long ago I modded my TPS by expanding the slots for the screws, so that you can slowly turn the TPS and adjust the settings at idle and full throttle with a voltmeter.

    Can I do the same thing with the HP tuner scanner?

    What are the optimal settings for idle and full throttle?

    I have searched on the forum, and I found .43 Volts at closed throttle, and 5.0 volts at full throttle.

    What should I use?
    Last edited by coachcrow56; 02-02-2020 at 05:52 AM.
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!

  2. #2
    Advanced Tuner coachcrow56's Avatar
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    The reason for my first post is that sometimes when I crank the car, I get a crazy high idle speed. But its not every time--weird.

    With the key on, engine off, these are the readings that HPTuners Scanner gives me.
    Throttle position 0%-------.43 volts
    Throttle position 100%---4.31 volts

    Are these good, or do I need to adjust it??
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!

  3. #3
    Advanced Tuner ZeroBoostBuick's Avatar
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    The Idle Control Valve is probably worn or dirty and is sticking.

    It's more common than you think on 3800 cars.

  4. #4
    Advanced Tuner coachcrow56's Avatar
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    I cleaned it and the bore where it is installed---didn't make any difference.
    Last edited by coachcrow56; 02-05-2020 at 12:01 PM.
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!

  5. #5
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    Quote Originally Posted by coachcrow56 View Post
    I cleaned it and the bore where it is installed---didn't make any difference.
    Have you replaced the IAC motor/valve? I had that issue some years ago and thats what fixed it. Log your IAC desired and actual postion...
    Last edited by jaydubb71; 02-05-2020 at 04:58 PM.
    Daily Driver= 1998 Pontiac Grand Prix GTP Coupe (3.4 pulley, SD Headers, SLP catback, FWI, 180 t-stat, hotwired FP, Autolite 103's, poly dogbone bushings, solid rubber engine and trans mounts, self tuned with HP Tuners)
    Weekend Cruiser= 2009 Pontiac G8 GT (Vararam, TSP LS3 N/A Stage 1, OBX, CTS-V converter, MagnaFlows w/ J-Pipes, 160 t-stat, self tuned with HP Tuners)
    Project Car= 1991 Chevrolet Camaro RS (On3 7875, LM7 build on hold)
    Truck= 1995 K1500 ECSB 5.0 5-speed (Dusty...)

  6. #6
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    Quote Originally Posted by coachcrow56 View Post
    The reason for my first post is that sometimes when I crank the car, I get a crazy high idle speed. But its not every time--weird.

    With the key on, engine off, these are the readings that HPTuners Scanner gives me.
    Throttle position 0%-------.43 volts
    Throttle position 100%---4.31 volts

    Are these good, or do I need to adjust it??
    TPS looks good!
    Daily Driver= 1998 Pontiac Grand Prix GTP Coupe (3.4 pulley, SD Headers, SLP catback, FWI, 180 t-stat, hotwired FP, Autolite 103's, poly dogbone bushings, solid rubber engine and trans mounts, self tuned with HP Tuners)
    Weekend Cruiser= 2009 Pontiac G8 GT (Vararam, TSP LS3 N/A Stage 1, OBX, CTS-V converter, MagnaFlows w/ J-Pipes, 160 t-stat, self tuned with HP Tuners)
    Project Car= 1991 Chevrolet Camaro RS (On3 7875, LM7 build on hold)
    Truck= 1995 K1500 ECSB 5.0 5-speed (Dusty...)

  7. #7
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    Quote Originally Posted by ZeroBoostBuick View Post
    The Idle Control Valve is probably worn or dirty and is sticking.

    It's more common than you think on 3800 cars.
    Lord have mercy, yes it is! LOL! Im the original owner and I've had this same issue.
    Daily Driver= 1998 Pontiac Grand Prix GTP Coupe (3.4 pulley, SD Headers, SLP catback, FWI, 180 t-stat, hotwired FP, Autolite 103's, poly dogbone bushings, solid rubber engine and trans mounts, self tuned with HP Tuners)
    Weekend Cruiser= 2009 Pontiac G8 GT (Vararam, TSP LS3 N/A Stage 1, OBX, CTS-V converter, MagnaFlows w/ J-Pipes, 160 t-stat, self tuned with HP Tuners)
    Project Car= 1991 Chevrolet Camaro RS (On3 7875, LM7 build on hold)
    Truck= 1995 K1500 ECSB 5.0 5-speed (Dusty...)

  8. #8
    Advanced Tuner coachcrow56's Avatar
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    I cleaned and replaced it today----here is scan that followed---its still surging----and my tune file
    Attached Files Attached Files
    Last edited by coachcrow56; 02-05-2020 at 06:11 PM.
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!

  9. #9
    Advanced Tuner ZeroBoostBuick's Avatar
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    The IAC being a stepper motor has gears inside, and they're plastic. And little plastic teeth don't last forever.

    If you have any scans from before when it was working good, compare the MAF lbs/min just to make sure it's not the MAF.

    Look at the Hz and lbs/min at the same RPM idle at about the same engine coolant temp.

  10. #10
    Advanced Tuner ZeroBoostBuick's Avatar
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    took a quick look into your tune and your high idle rpm Timing is way too high. ECM might be fighting this high timing. but it doesn't explain why it's doing it when the engine is up to temperature because the high idle timing is only at 1,000 rpm and higher.

    IdleRPM.png
    Last edited by ZeroBoostBuick; 02-06-2020 at 08:48 PM.

  11. #11
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    Quote Originally Posted by ZeroBoostBuick View Post
    took a quick look into your tune and your high idle rpm Timing is way too high. ECM might be fighting this high timing. but it doesn't explain why it's doing it when the engine is up to temperature because the high idle timing is only at 1,000 rpm and higher.

    IdleRPM.png
    I'm willing to bet its the IAC motor. I've been down this road with my GTP before. Wayyyy before I got into tuning. I will look at his logs later today.

  12. #12
    Advanced Tuner coachcrow56's Avatar
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    Thanks for looking at my tune. I am going to try this today. I am going to go back to a 2005 GTP timing table that I used once before, and try the idle tables too. I will post the results later today---hopefully that solves my problem.
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!

  13. #13
    Advanced Tuner coachcrow56's Avatar
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    I have tried two TPS sensors, one brand new that gives me reading of .37 V, and a modified TPS where I can adjust it to .43 V. And I ordered 2 brand new Idle Air Controllers from ZZP, and tried both of them, and adjusted my IAC counts anywhere from 20 to 40, and it makes no difference. I still get a surging idle with any combination. Could my fuel trims be off just enough to cause a surge? I am sure that I don't have a vacuum leak, so what could it be?

    This morning I adjusted my TPS and my IAC until I got a fairly smooth idle---its not perfect but it does have a cam.

    I am attaching a scan and my current tune. Could someone tell me if I am missing something??
    Attached Files Attached Files
    Last edited by coachcrow56; 02-22-2020 at 10:49 AM.
    3.2 Pulley/CAI/1.6 HS Rockers/Hi Energy Comp Cam 76-802-9/LS7 Lifters/ZZP Intercooler/Headers/2500 Stall Converter/NGK TR6IX/ZZP Fuel Rails/100 shot NOS/GMPP Sway Bars//I forgot the rest!!!