2G TPS and IAC Problems

[Spanky_DSM]

Ok so i tested my IAC and found a dead coil, pins 5 and 6.
Swapped it with a good one and while i was at it i checked my TPS.

closed it read 1.5 or so and open was around 5.7 or so

so i adjusted it at closed throttle to .63 and oped it read 5.7 or so.

I went for a cruise and now while im driving, cruising like a grandma (no were near boost) releasing the throttle the rpms drop all the way to 200 and pick up right after.

I mean tip toeing the throttle and releasing it will cause the rpms to drop.

it never did this before i adjusted the tps.

are my tps specs in check?

EDIT..

just went out and adjusted the biss screw.

it was pretty far out..

took a cruise and wasnt bogging after closing the throttle but ill see what happens when i take a longer drive.

those specs are correct to for the tps right?

i read somewhere saying that VFAQs how to was incorrect

 

[DSM1G90]

You replaced the IAC, but never calibrated it for the BISS screw.

Go back to VFAQ (read here .... http://www.vfaq.com/mods/BISS-2G.html ) and read the section on calibrating the IAC for the BISS screw. Then, you can have a good idle.

TPS readings are close. Closed throttle plate should be close to .50 .

 

[Spanky_DSM]

Thanks pal for the info..

a couple hours too late but yeah i read up somewhere about adjusting that after replacing the iac

but your input is greatly appreciated and thanks for the link.

Way better than what i had read on a similar thread

 

[Spanky_DSM]

Okay, This problem is still going on.

.63 at closed.

But at 100% throttle the TPS reads 5.6 or so... Is that bad? shouldnt it be around
5v?

Car acts normal but the only problem is since adjusting the TPS, is my gears chane way too quick.

I could be in 3rd going around 25mph. (automatic Transmission)

Before i dont know what the TPS was adjusted to but the gears were pretty good.

 

[ibreakmytsi]

Have you checked vfaq, I have always had my tps set closer to .9

 

[steve]

Have you checked vfaq, I have always had my tps set closer to .9

And that would be wrong regardless is it was voltage or resistance you were measuring. The VFAQ process is flawed, without measuring the total resistance of the TPS you can't know what to set TPS pin 1 to pin 2 to resistance wise.

Setting the TPS voltage is the recommended procedure unless you have made all the measurements and understand how a voltage divider works.

closed it read 1.5 or so and open was around 5.7 or so

so i adjusted it at closed throttle to .63 and oped it read 5.7 or so.

On a normal working car the TPS voltage should not exceed 5.0v, something isn't right.

 

[Spanky_DSM]

Well i have other TPS's laying around but their max output on WOT is about 4.75 volts.

Should i use that one instead?

 

[steve]

Until you figure out why you were seeing a TPS output greater than the +5v sensor power (shouldn't be possible) changing the TPS to one that reads lower sounds like masking not solving.

Double check the +5v sensor power to the TPS with your multimeter, it should be within 0.1v of 5.0v.

Are you running DSMLink?

2G's critical TPS adjustment is the Idle Position Switch that's part of the TPS.
(2G TPS pins are 1- 5v, 2- TPS output, 3- IPS output, 4-ground)

Most of the TPS tests are the same 1G and 2G, the total resistance between pins 1 and 4 should be between 3.5k and 6.6k ohms. The resistance between 1 and 2 and 2 and 4 should change smoothly as you rotate the TPS through it's full range. On the 2G the IPS is connected between pins 3 and 4. It should switch with low resistance.

To adjust the 2G TPS you place a .177" feeler gauge between the stop screw (fixed SAS) and the throttle pulley to open the butterfly and then adjust the TPS right to the point where the IPS (pins 3 and 4 on the TPS) switches from closed (0 ohms) to open (infinite ohms).

Then you verify that the TPS (pin 2 and 4) reads between 0.4 and 1V while the feeler gauge is still in place. Anything in that voltage range is OK as long as the IPS is adjusted correctly. If it's not correct you need to check that pin 1 is about 5v and pin 4 is grounded. If they are correct then the TPS is bad.

There is no way to adjust the TPS voltage independently of the IPS on a 2G. Trying to correctly set a 2G TPS by voltage will only work by dumb luck. The factory ECU software doesn't really care what the absolute WOT voltage is, it looks at the changes in voltage from one second to the next.

 

[AWDtalontsi96]

Until you figure out why you were seeing a TPS output greater than the +5v sensor power (shouldn't be possible) changing the TPS to one that reads lower sounds like masking not solving.

Double check the +5v sensor power to the TPS with your multimeter, it should be within 0.1v of 5.0v.

Are you running DSMLink?

2G's critical TPS adjustment is the Idle Position Switch that's part of the TPS.
(2G TPS pins are 1- 5v, 2- TPS output, 3- IPS output, 4-ground)

Most of the TPS tests are the same 1G and 2G, the total resistance between pins 1 and 4 should be between 3.5k and 6.6k ohms. The resistance between 1 and 2 and 2 and 4 should change smoothly as you rotate the TPS through it's full range. On the 2G the IPS is connected between pins 3 and 4. It should switch with low resistance.

To adjust the 2G TPS you place a .177" feeler gauge between the stop screw (fixed SAS) and the throttle pulley to open the butterfly and then adjust the TPS right to the point where the IPS (pins 3 and 4 on the TPS) switches from closed (0 ohms) to open (infinite ohms).

Then you verify that the TPS (pin 2 and 4) reads between 0.4 and 1V while the feeler gauge is still in place. Anything in that voltage range is OK as long as the IPS is adjusted correctly. If it's not correct you need to check that pin 1 is about 5v and pin 4 is grounded. If they are correct then the TPS is bad.

There is no way to adjust the TPS voltage independently of the IPS on a 2G. Trying to correctly set a 2G TPS by voltage will only work by dumb luck. The factory ECU software doesn't really care what the absolute WOT voltage is, it looks at the changes in voltage from one second to the next.

I just checked my TPS on my 2g and closed throttle is 0.14 ohms between 3 and 4. if I rotate it real slow it goes to like 0.20 and the infinite. So is that good or the ohms have to be at 0.00 ohms

 

[steve]

I just checked my TPS on my 2g and closed throttle is 0.14 ohms between 3 and 4. if I rotate it real slow it goes to like 0.20 and the infinite. So is that good or the ohms have to be at 0.00 ohms

Having ~0.2 ohms resistance in the IPS switch shouldn't be a problem as long as it switches at the right point in the throttle travel. That's what the 2G TPS adjustment does, make sure the IPS switches at the right point.

 

[AWDtalontsi96]

Having ~0.2 ohms resistance in the IPS switch shouldn't be a problem as long as it switches at the right point in the throttle travel. That's what the 2G TPS adjustment does, make sure the IPS switches at the right point.

OHHH okay I see whats happening then. Right now its against the throttle stop. at 0.14 and as I open the TB just a ever so slighty the idle switch is still connected we'll say .so once I press it alittle more it final disconnects and by that time the TB is open more then it should be and it switch to the fuel maps and the car kinda jerks forward.

 

[AWDtalontsi96]

So I finally got it dialed in as close to perfect as possible. Having it set at the 0.2 ohms wasn't working cause the ecu was seeing 14% throttle which made the car run like crap at idle. I adjusted the TPS using evoscan and got it at 10.5% and its perfect. Smooth on and off throttle , goes into idle nice. Before it was set to like 6.8% at idle which was way to low. So by the time it hit 11% which is were the ecu goes from idle maps to regular maps it would jerk the car pretty good.