TurboDave has been helping me with my TPS settings- Thanks Dave- in another thread and I have tried two new AC Delco TPS sensors with the same results as the old sensor, which is less than a year old. So that makes three sensors (four if you count the one that came on the car) that read 4.2 volts (give or take a couple hundrethes) at WOT. I read somewhere that anything over a certain value is fine, causing the ecm to go into power enrichment mode (whatever that is). I am hoping that value is 4 volts. Can anybody help? Sensor is pulled as far forward as possible, and it reads .46 volts at idle. I set it with key on, engine off. Thanks.
TPS at WOT? Mine might be low.
- Thread starter GNRick
- Start date
From Steve Wood's site
Let's start with wide open throttle settings.
Folk lore has long taught that some magic number such as 4.65 volts, or 4.80 volts is required from the TPS in order for the ECM to command Power Enrichment which provides the additional fuel required which the engine is under boost.
If you go Here and look at the chip dumps provided by Dave Huinker, and go down to line 1410 of the dump, you will see the factory adds maximum enrichment at 75% of TPS which is 3.75 volts. Any number beyond this provides the same fueling. There are no magic numbers.
Let's start with wide open throttle settings.
Folk lore has long taught that some magic number such as 4.65 volts, or 4.80 volts is required from the TPS in order for the ECM to command Power Enrichment which provides the additional fuel required which the engine is under boost.
If you go Here and look at the chip dumps provided by Dave Huinker, and go down to line 1410 of the dump, you will see the factory adds maximum enrichment at 75% of TPS which is 3.75 volts. Any number beyond this provides the same fueling. There are no magic numbers.
mikestertwo
Well-Known Member
- Joined
- Sep 13, 2006
4.2 volts is plenty high. Don't sweat it, your fine. Don't chase a problem that isn't there. 
In case there is a change in code.. contact your chip maker and confirm the value.
Typically to get the high(4.5vdc+) out of a TPS at WOT, you need to loosen the mounting screws(like if your going to set it) and pull the sensor forward torwards the radiator.. once pulled(yanked) forward then set your TPS to .38-.46.. keep pressure in the forward direction... if you let the sensor slide torwards the firewall.. you'll get low WOT voltages.. then go check your WOT and you'll be suprised
Typically to get the high(4.5vdc+) out of a TPS at WOT, you need to loosen the mounting screws(like if your going to set it) and pull the sensor forward torwards the radiator.. once pulled(yanked) forward then set your TPS to .38-.46.. keep pressure in the forward direction... if you let the sensor slide torwards the firewall.. you'll get low WOT voltages.. then go check your WOT and you'll be suprised
Thanks, that's what I wanted to hear.
It's a turbo tweek chip. I pulled the sensor forward and snugged it a little. Then I tapped it down a little at a time until it read .46. Then I checked it at WOT but only got 4.2. Maybe I just don't have the touch.In case there is a change in code.. contact your chip maker and confirm the value.
Typically to get the high(4.5vdc+) out of a TPS at WOT, you need to loosen the mounting screws(like if your going to set it) and pull the sensor forward torwards the radiator.. once pulled(yanked) forward then set your TPS to .38-.46.. keep pressure in the forward direction... if you let the sensor slide torwards the firewall.. you'll get low WOT voltages.. then go check your WOT and you'll be suprised
On my last run I saw LV8 at 255, like the MAF. So I'm ok there too.
a little trick I learned from someone locally...
find a drill bit that is the same diameter as the mounting slots on the TPS sensor. use a drill and extend the mounting slots to allow you to move the TPS sensor farther forward. it doesn't take much to make a difference.
as far as there not being a "magic voltage" I don't know much about it. I know there are a few sources out there that say 4.5V is the magic number, but that might be BS.
Casper's Electronics sells a "TPS TEC" which plugs in-line between the TPS and the engine harness. I have one mounted in my GN, but it's not hooked up at the moment. I can't really say I've noticed much difference with or without it connected.
find a drill bit that is the same diameter as the mounting slots on the TPS sensor. use a drill and extend the mounting slots to allow you to move the TPS sensor farther forward. it doesn't take much to make a difference.
as far as there not being a "magic voltage" I don't know much about it. I know there are a few sources out there that say 4.5V is the magic number, but that might be BS.
Casper's Electronics sells a "TPS TEC" which plugs in-line between the TPS and the engine harness. I have one mounted in my GN, but it's not hooked up at the moment. I can't really say I've noticed much difference with or without it connected.
Dumb question, if you manually open the throttle blade, how high does the TPS go?
I guess I could try that, but I'd rather believe Steve Wood and leave it alone.
another tip:
check the throttle cable for "slack" under the dash(gas pedal--where cable connects), we have seen this before.....quick fix--wire tie the cable between the pedal and the outside sleeve of the throttle cable. Kinda-like a spacer(plastic wire tie) to remove the slack" in the cable.
Put one on our car about a year-ago, still there and no problems and WOT tps before was 3.9 and after quick-fix 4.65.
check the throttle cable for "slack" under the dash(gas pedal--where cable connects), we have seen this before.....quick fix--wire tie the cable between the pedal and the outside sleeve of the throttle cable. Kinda-like a spacer(plastic wire tie) to remove the slack" in the cable.
Put one on our car about a year-ago, still there and no problems and WOT tps before was 3.9 and after quick-fix 4.65.
Nah.. your complicating something simple... turn ignition ON.. put the scanmaster on TPS.. open the hood.. get someone to look at the reading on the scanmaster.. get your hand and rotate the throttle blade wide open. Same way you would rev the engine while idling.
If you crack the blade open all the way and it reads higher than 4.2, then check your accellerator cable, floor mat interference, etc..
Hi Agteacher,
I had no clue what you are talking about, so I went out to the car and noticed the gas pedal has alot of slop in it. It looks like I would have to remove the plastic shield covering the underside of the dash, to perform your remedy. then I remembered that the TPS is the same whether or not I manually depress the acelerator cable or if someone is in the car and depresses the gas pedal with the floor mat removed.
have someone push the gas pedal to the floor(remove floor mats 1st) then, go to the throttle bracket cable and "see" it you can push the cable(using the bracket on the throttle body) with your hand, also have the person inside look at the scanmaster.
Ok, I did what you said....just like if I rev the engine. This makes no difference, just like if someone pressed down on the acc. pedal with the floor mat removed. I also performed one other test- I pressed down on the metal clip on the tps sensor and volts went to 4.89. So either the sensor is not positioned correctly or the acc. cable doesn't go far enough. Or 4.2 is good enough and that is how the acc. cable was manufactured for my car. I just don't know. I can do what agteacher suggested tomorrow to check for slop in the cable. I do know that when the cable is stretched (like if I were reving the engine) there is no slop in the cable under the hood. Thanks.
Then simply your not being forceful enough "yanking" the sensor forward.
If the throttle cable and TV cable are tight when the pedal goes down, and the throttle blade does not have any more movement, then you can leave things as are and 4.2 is not an issue.
My concern was the "floor mat issue" these cars have that doesnt allow 100% extension of the TV cable
If the throttle cable and TV cable are tight when the pedal goes down, and the throttle blade does not have any more movement, then you can leave things as are and 4.2 is not an issue.
My concern was the "floor mat issue" these cars have that doesnt allow 100% extension of the TV cable
I've looked at Steve's site before...never hurts to look at it again. Thanks. He says 3.75 volts is ok at WOT. I looked at a few things that happen when I adjusted TPS. First, cable goes as far as it can before it hits the "stop". This is when someone is in the car or I do it by hand. So I think cable is good (floor mat removed). Then I noticed that if you tighten the IAC air adjuster screw, it will eventually push the acc. cable forward at the black metal piece that you push down on manually to rev the motor. To increase TPS, I don't want to push down the black metal piece. I wanted to manually slide upwards the tps sensor. This way when you press down the accelerator pedal, the metal clip on the tps sensor has further to go, thus increasing voltage. If the metal clip on the tps sensor is already being pushed at idle, then it has less distance to travel to get to WOT. At least that is how I see it. Bottom line, I can't get WOT past 4.2 volts.
You could be right.
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