Calibrating the Voltage on the TPS

[beeza]

Now,turn the car keys turned to the second click,so the lights on the dash come on.Then perform these tasks -

Set your multi meter to volts.We are looking for a range of 0-5 Volts,so the 20V setting is best:



Positive probe to positive wire and negative probe to negative wire:



Note: You can wedge the probes under something to stay on the pins,without the need to hold them.This will allow you to do this by your self.


THESE VOLTAGES ARE THE SAME FOR ALL HONDA'S

0.48V @ CT (Closed Throttle)

4.5V @ WOT (Wide Open Throttle)

Now,hold the Throttle plate at WOT:



And turn the TPS until you get 4.5V on the multi meter:



Then tighten it back down:



Re-check the setting haven't changed after tightening the TPS.

After you have done that,check the voltage at CT (Closed Throttle).This is where the TS screw (Throttle stop) will need to be adjusted to set the CT Voltage.

If you have a value greater than 0.48V,you will need to wind the TS screw out to open/increase the voltage range.If it's less,wind it in/up to close the gap/range.

Throttle Stop screw on the d16y4,from behind:







Adjust it like this with an Allen key:



Under here:



Firstly you will need to undo the nut on there to be able to turn the screw.Make sure the nut is tightened up when you set the values.



Undo/tighten the TS screw until you get a 0.48V Value for CT.

TIP: When you tighten the nut up with the ratchet,the voltage will increase slightly by 0.01V-0.02V.So,adjust the TS screw with the allen key to 0.46V-0.47V value and tighten the nut up good with your ratchet.This way you will get the required 0.48V and a tight nut on the TS screw!

Now,re-check the WOT value.I bet it has moved? It maybe at 4.52 for example.So CT is at 0.48 and WOT at 4.52,so the range is 0.02 too much.So we need to close the range in by 0.02.Do this via the TS screw.Turn it up to 0.50.Then set WOT again at 4.5V by turning the TPS until you see this value,tighten it back down.CT should now be 0.48V and WOT at 4.5V.



VIDEO:

This is the final result,a perfectly set up accelerator pedal and Throttle body,performing at it's best!

You can hear CT and WOT stop's being contacted.The pedal feels perfect.At the same time the pedal is contacting with the floor,the WOT stop is being contacted on the Throttle body.At CT there is no significant 'load' on the pedal but there is tension in the cable,keeping the pedal firm with no free play.Perfect.



Between the TS screw,moving the TPS and the tensioning the accelerator cable and a bit of patience,this can be achieved.

Note: If your car is an automatic and you cant get both value's,your gearbox cable maybe too tight and restricting movement,like mine was.I could get 0.48V but Wide Open Throttle was 4.33V.I loosened off the gearbox cable and I could get 0.48V and 4.5V easily.The cable was restricting movement.

You will need to loosen off the cable to free up some movement,it's the same set up as the accelerator cable:



If your automatic 'kicks' into gear,like too much then your gearbox cable is too tight,Loosen it off.

Also,be wary your carpet under the accelerator pedal may be restricting the pedal and may need to be removed like mine did to get a better pedal.

If U get WOT,4.5V and can only get say 0.52V for CT.This means U need to increase the range at which the throttle plate moves by 0.04V.To do this U can simply file a small amount off the throttle rotor,like this:





Then set the WOT again first,then the CT,done!

After your done,set the idle via the idle air adjust screw.



Make sure the car is fully warmed up and simply turn the screw until the idle is where you want it.For a manual car,set the idle when the car is in neutral and for a automatic car,set the idle with the car in 'D'.It's 'D' that you will be sitting in at lights,so that's where you want to set it,not Park,'P'.

When you reset the ECU it will even the idle out.

Now we need to check that the values are the same at the ECU end.This will ensure the wires are fine and the ECU is seeing the same readings.

Remove the kick panel at the passengers feet to expose the ECU and wiring,1 clip and a bolt (How cool is the big march fly in the shot!):





Don't stab and ruin the wires like I did,stick the pins up into the connector,like this:





Closed Throttle:



Wide Open Throttle (WOT):



Also:

* Probe the Yellow and green wires to verify that you have 5v going to the TPS.

* Check the reading starts at 0.48V and smoothly increase to 4.5V,showing you have nice smooth throttle increase/decrease coming from the TPS to the ECU.This will verify the wiring between the TPS and ECU is fine.

VIDEO:



After you have completed that Reset the ECU and bleed the air from your coolant lines.This can be done by parking your car on a hill so that the engine is the high point,this will allow the air to escape easier.Start the car up,pop the hood and undo the radiator cap,take it right off so you can watch the air escaping.Just let it idle for a few minutes (at least the fan comes on twice).Give the coolant hoses a squeeze to help the air escape.

Your car will run better with no air in the coolant system.

NOTE: If U experience a high idle that goes up to 2,000rpm and then drops off and keeps repeating this (as discussed on page 8),chances are the Throttle plate is a bit open and needs closing.First try screwing in the idle/air screw on the top,if that dosen't do the job,probably won't,you will need to screw the TS screw out to close the throttle plate.The CT voltage will read 0.44V or so when the idle stabilizes but don't worry it shouldn't affect the performance of the car as I am learning).

IF the idle persists to be erratic,i.e. quite bad then look to fix the problem via the FITV - You-Have-Cleaned-the-IACV-BUT-Your-Idle-Is-Still-High-Erratic-Adjust-The-FITV.

Here is another GREAT DIY U can do aswell! Modifying-the-stock-Throttle-body-for-more-air-flow

Enjoyz!

Still doubt how effective this is?

This is quoted from JohnL our very own resident Suspension Expert! (Taken from this thread):

Yes it has definitely helped, the engine is significantly more 'drivable' now.Less clutch slippage is now needed on take off and some hills that used to need a downshift or largish throttle opening can now be driven up on a light throttle with no downshift. Downshift 'blips' are definitely more consistent / predictable with noticeably faster rpm rise.

I've been meaning to check this for ages, but since the engine was running acceptably I kept forgetting about it. I'm a bit surprised how much difference there is between 0.44v and 0.48v...

I can tell you that 0.04v below 0.48v is significant.

This seems most noticable when taking off from rest, appearing to require less clutch slippage with the engine feeling more 'muscular' at low rpm / light throttle opening. There also seems to be some improvement to throttle response when 'blipping' for 'rev matching' on downshift.

It's worked beyond expectations with my engine.

And....wait for it....

If the TPS CT voltage is off spec then the light throttle / low rpm torque will be adversely affected and the engine will be lacking in immediate response to lighter throttle inputs (and you spend 99% of the time at light throttle openings). This adversely affects the driveabilty of the car, and probably fuel economy as well.

Lack of low rpm torque is especially noticeable when taking off from rest, requiring more care / skill with balancing of the throttle input and clutch slippage because the engine is in greater danger of stalling.

You might think that if light throttle torque is poor then why not just open the throttle more, but this doesn't really work so well for 'normal' driving (you can get the same affect, but the engine feels like it's working a lot harder to achieve it). Having the TPS correctly calibrated can make the car much nicer to drive, particularly in traffic / around town.

I set CT to 0.51V and WOT at 4.53V for a week then put it back to 0.48 - BIG DIFFERENCE!

For Everything that I have ever learnt about Cars/honda's,this is by far the most important and effective.I wish everyone had this done already.Our Honda's would be tearing up the planet!

So skip the Hot chicks thread tonight for a change,read this a few times,get confident with it and....DO IT!