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Discussion Starter · #1 · (Edited)
2004 Pre-LP, manual.

For the last 2 days I've been rebuilding my TBs. Hopefully to fix the idle surge problem that almost all of these cars have. Instead of going to XeMODeX, I decided to do it myself. They use off the shelf parts, they arent special, surely it can be done in your garage?

Sort of. They use a Sacer TPS. I bought a Sacer TPS. I installed it, wired it up properly, and it actually works. The car starts, drives, and idles better than it ever has. The idle is perfectly smooth, it doesnt rev itself up in neutral anymore, it worked!

Only one little hiccup. The car doesnt understand how to handle the new TPS. It clearly isnt calibrated properly. The car feels like it has no horsepower. I was data logging during the test drive, and during WOT (pedal all the way down), the ECU says the TB is only 46% open. It feels like its only 46% open, too. It seems like the pedal is only doing about fraction of what it was doing before. (If any of you try to sell me a sprint booster, god help me) In some cases, when slowing down, I would get a battery light flashing. I figured my alternator belt was slipping, but I'm pretty sure the engine was actually stalling due to how low the RPM would drop. It would hit 700, 500, and at one point hit 445 before the engine totally died. Lost all power steering and braking. Almost hit my fence.

So the TBs do work, the idle surge is gone, but I need to find a way to calibrate them. The FSM states the following: "Turn the engine on and warm it up until water and oil are higher than 90C. Drive 10 km. Now the system starts a "self learning".

I could swear that I did the above, but maybe not. This has me thinking either the TPS just isnt going to work for some reason, or I need a TEXA/LARA to force it to recalibrate, or maybe something else. I feel like I'm 99% there. I cant find any evidence of anybody doing this before on these cars. It would be awesome if we could get it figured out. I'd make a writeup of everything I've done so far and people could stop blowing thousands on rebuilt units or "new" units. Later tonight I'm going to be checking all the ground wires and I'll try to do that self learning thing.

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Discussion Starter · #2 ·
@SanjaySchulz this sounds like something youd know about. You have a LARA, right?
 

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Hi 🖐 (Phill from FB) hope we can figure this out for the community! 1050 for the same service that is 550 for a volvo is just ridiculous.
 

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If we can figure out what the pin out on the throttle bodys are id be happy to try and get readings of the module powered up, but it doesn't seem like the gallardo leaves them powered after the initial self check.
 

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Discussion Starter · #6 ·
Working with glumpy3 to get it going. He has his OEM throttle bodies apart and is helping me out by giving me reference voltage. I think we are very close to getting it working.
 
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Any news? I really want to do this with my throttles. A friend of mine did it twice for Volvos. It sounds and looks a bit scary to do the mods, but would be awesome if it works.

Good luck and let us know what happens!
 

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Discussion Starter · #8 ·
Yes. I did it, it worked. I was going to make a write-up but honestly I dont think anybody on here would actually attempt it so I decided not to spend the time making a thread about it. But yeah, its doable.
 

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Nice!
How did you calibrate it?
This is a description in Swedish how to do it, but please tell us how to recalibrate.
In this video Volvo had to recalibrate afterwards.

Is this the Sacer you used?

Very well done! I'm impressed
 

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Discussion Starter · #10 ·
You dont need to do any ECU calibration or any software based TPS calibration.

All you have to do is get the fully open voltage to the value the ECU expected. This is the part that took multiple days of trial and error. The voltage you want is 1.399V. It doesnt have to be right on, but it has to be very close. 1.38 - 1.40V is probably the reasonably safe range. Glumpy measured his OEM TBs at 1.36V and 1.41V, but he was also having problems with his, so those arent necessarily the correct answers. My 1.399V works perfectly. My first try, I set the car up with the voltage at 1.5V on each TB and nearly crashed the car because it stalled and totally shut off while driving due to the RPMs dropping so low.

You tune the fully open voltage by rotating the sacer magnet on the TB shaft. Rotate it one way, the voltage decreases. Rotate it the other way, the voltage increases. On both of my units, I had to cut an angle into the TB shaft to allow the magnet more degrees of rotation. The voltage is incredibly sensitive to the location of the magnet. I was marking the TB with a razor blade, and the thickness of the blade was giving me a 0.05V variation.

Everything below is a paste from a conversation with Glumpy, telling him how to measure the voltage. This is what you want to measure to dial it in. Explanation of photos is below them all.

Edit: Uploading images in another comment because this forum wont allow it in this one.
 
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Discussion Starter · #11 ·
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Okay now let me explain all of these photos

so you measure voltage using pins 1 and 3 on the sacer TPS side. Aka the side with 3 prongs, not 5.

I don't have alligator clips for my meter, so I'm using wire lengths attach to my leads and heat shrink tubing to hold the wires on pins 1 and 3. If you have alligator clips you can use those.

I don't have the sacer tps soldered, so I'm just clamping it on with a woodworking clamp and bending the pins so they make contact. This would take months soldering it every time.

i plug in the tb to the car, set my meter to measuring dc volts. It's auto ranging but if not you'd set it to 20. I then use something to prop up a phone and set it to video record the meter

while that's recording I open the door and turn the car to aux2 you'll hear it prime the fuel pump and run the OK check. Shut it down and check the recording
 
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Discussion Starter · #12 ·
This project took over a month. Willing to answer any questions for anybody who is doing this
 
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That's awsome, thanks!

Here are some questions:
1. There is a flat part of the axle and the same at the magnet so it can't be rotated. You mentioned you had to grind an angle at the axle. Was it to enable the rotation?

2. Can you then trust the nut to hold the magnet at exact the right place all the time? It feels like it will move just a little bit and then mess up the voltage value?

3. You say that 1.399V is at fully open? Is that tested in the startup test process? You never mention that you press the gas pedal each time. Can't I just fully open the throttle with my fingers and rotate the magnet until I got the correct value? Probably not, but I ask the question anyway.

Thanks for all help so far! Now it would be nice to have two old throttles as test objects.
 

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What do you think about this post from "boosta"?
"Lamborghini Injeczione Electronica or LIE, they are different they self learn when oil and coolant temps are to proper temps 90C on oil and 100C on coolant,until then the LIE use last stiochometric report stored in system to run engine."

GoatPuncher, did you reach 90C oil and 100C coolant when testing? 100C coolant is a lot (for a normal car at least).
Maybe the throttle will self adapt after all???
 

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Discussion Starter · #16 ·
1. There is a flat part of the axle and the same at the magnet so it can't be rotated. You mentioned you had to grind an angle at the axle. Was it to enable the rotation?
Yes it can. It is a loose fit. It rotates a millimeter or two in both direction, which is fairly significant. But yes, you grind it more so it rotates further. Dont grind anything until you see how close you can tune it without grinding. That way you know how much to grind off. The more you take off, the more sensitive it becomes to adjustment. I ground down my second TB a bit too much and it took me an entire day to get it adjusted. Take it slow and you'll finish a lot faster.

2. Can you then trust the nut to hold the magnet at exact the right place all the time? It feels like it will move just a little bit and then mess up the voltage value?
Yes, but you have to be careful when tightening it down. After getting the voltage right you can apply blue loctite. I applied the loctite while the bolt was attached. The gap I cut allowed it to seep in anyway. I later took apart the TBs for finishing touches (potting, mostly) and the nut was very hard to remove, so i trust it.

3. You say that 1.399V is at fully open? Is that tested in the startup test process? You never mention that you press the gas pedal each time. Can't I just fully open the throttle with my fingers and rotate the magnet until I got the correct value? Probably not, but I ask the question anyway.
I dont press the gas. Opening the baffle yourself isnt going to apply voltage to the TB. Measuring resistance isnt a reliable way to tune it, either. I tried to figure out how to convert measured resistance to measured voltage, but couldnt get it reliable enough to trust it. When you turn the car into Aux 2, part of its startup diagnostic check is to make sure the TB moves. All it looks for is a voltage change. To do this it opens the throttle and then closes it. On the meter you will see full close voltage -> full open voltage -> full close voltage. By the time the car shows "OK" on the dash, it has done the test. That is the reason for the camera. Only other way to do it is to apply voltage yourself. I didnt want to risk frying anything due to being unable to find a pinout, so I didnt do that, but it is an option. Also, the pinout is NOT the same as the one on VW cars. The wiring harness changed.

"Lamborghini Injeczione Electronica or LIE, they are different they self learn when oil and coolant temps are to proper temps 90C on oil and 100C on coolant,until then the LIE use last stiochometric report stored in system to run engine."
Yes, I did multiple self-learn procedures and none of them made a difference. The reason is because when the car does its startup check, it isnt trying find out what full open voltage is. Its only looking for a change in voltage to make sure the TB is responding.

Say you set the voltage to 1v. When the car starts up, it will see 0v -> 1v -> 0v. The car is dumb, though, and doesnt accept 1v as the new "full throttle" voltage. It just sees the voltage change and says "everything is working!"

All the self-learn procedure does is help the car keep its self running. You can look at data logging with the wrong voltage and you'll see exactly what its doing. The reason for this is because if you have the voltage wrong, the idle RPM will be wrong, and the car will adjust for this. It isnt actually trying to remap full throttle.

It isnt as perilous as it sounds, though. These are not precision devices and are not expecting a single voltage to operate. They expect a small range, but unfortunately I dont know what that range is. I just know that 1.35 is too low, 1.5 is too high, and 1.399 works exactly like stock. I assume the correct voltage is actually 1.4 and the range is something like 1.38 -> 1.42 just from the OEM measurements glumpy got me, but this data isnt public and it isnt the same as the VW guys. So this is the best we have.
 
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Discussion Starter · #17 ·
Something else I want to note..

Like I said, I spent about a month experimenting and figuring this out, and I tried to take every shortcut possible to see if it would work. I think I have a very good idea of how this works and how to solve it, however..

There is a lot of misinformation on the lamborghini forums about this. I'm not talking about boosta above, but in my research I found a lot of threads where people were very confidently talking about processes that either dont exist or just do not work.

  • The sprint booster doesnt solve this. It isnt even a bandaid fix. If your TBs are going bad, it will amplify it. If your car is revving its self up in neutral and you have a sprint booster. REMOVE IT. I promise you the problem will be improved. It will still be there, but it might be more manageable
  • You cannot plug-and-play volvo TBs. The wiring harness is different, and all of my research has led me to believe the internal components are different enough that the ECU would have trouble. Also, the OEM volvo voltage probably would not be correct for the Gallardo. With that said, Volvo released a fix for their TB issue. Their fix is the reason we can buy the Sacer TPS units. The fixed Volvo units were touchless TPS and used Sacer as an OEM component. This might have a better chance of working if you got the pinout right, but I havent tried it and honestly it might be more trouble than its worth.
  • You cant swap to LP560 TBs without an entire ECU swap or a piggyback unit. Someone has gotten the swap working, but they need a Syvecs ECU, so its very expensive and somewhat defeats the purpose. If you already have an aftermarket ECU, it still isnt easy, but it is technically possible.
  • Your TB doesnt care if its dirty. There are a lot of posts on here where people are talking about ridiculous cleaning regimens with their TBs. I read a post where somebody said they spent hours cleaning them with precision dental tools. Unless you have measurable layers of grime or deposits all around the TB, your car doesnt know or care. I would bet all of the people who "fixed" this by cleaning the TB actually fixed it by unplugging and reseating the electrical connector.
  • You do not need any calibration procedure for this conversion to work. Its a very simple process, so as long as you show the car the voltage it wants to see, it will work.
  • xemodex does not do anything special. They also dont know the correct voltage for these. They modified their VW test bed to work with Gallardo TBs. The procedure you're planning to do is the exact same procedure they do, except they built a testbed to run the TB outside of the car so they can get it done a lot faster.

And yes, these TBs are a 100% failure rate. With enough miles and with enough time, yours will fail, and they arent making them anymore. On a long enough timeline, assuming ICE cars are even still legal, these TBs wont exist. Everybody will have to be rebuilding them to keep these cars going, which is why I wanted to post a detailed write-up. I just know very few people will bother to do it themselves. Most lamborghini owners would rather throw $2000 at xemodex (which, honestly is fine. If you value your time more than your money, thats probably the way to go)
 

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Thanks for posting this!, I've had a pair of conversion kits on the shelf for a while and this info will be a great help when I get the time to do this!
 

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Something else I want to note..

Like I said, I spent about a month experimenting and figuring this out, and I tried to take every shortcut possible to see if it would work. I think I have a very good idea of how this works and how to solve it, however..

There is a lot of misinformation on the lamborghini forums about this. I'm not talking about boosta above, but in my research I found a lot of threads where people were very confidently talking about processes that either dont exist or just do not work.

  • The sprint booster doesnt solve this. It isnt even a bandaid fix. If your TBs are going bad, it will amplify it. If your car is revving its self up in neutral and you have a sprint booster. REMOVE IT. I promise you the problem will be improved. It will still be there, but it might be more manageable
  • You cannot plug-and-play volvo TBs. The wiring harness is different, and all of my research has led me to believe the internal components are different enough that the ECU would have trouble. Also, the OEM volvo voltage probably would not be correct for the Gallardo. With that said, Volvo released a fix for their TB issue. Their fix is the reason we can buy the Sacer TPS units. The fixed Volvo units were touchless TPS and used Sacer as an OEM component. This might have a better chance of working if you got the pinout right, but I havent tried it and honestly it might be more trouble than its worth.
  • You cant swap to LP560 TBs without an entire ECU swap or a piggyback unit. Someone has gotten the swap working, but they need a Syvecs ECU, so its very expensive and somewhat defeats the purpose. If you already have an aftermarket ECU, it still isnt easy, but it is technically possible.
  • Your TB doesnt care if its dirty. There are a lot of posts on here where people are talking about ridiculous cleaning regimens with their TBs. I read a post where somebody said they spent hours cleaning them with precision dental tools. Unless you have measurable layers of grime or deposits all around the TB, your car doesnt know or care. I would bet all of the people who "fixed" this by cleaning the TB actually fixed it by unplugging and reseating the electrical connector.
  • You do not need any calibration procedure for this conversion to work. Its a very simple process, so as long as you show the car the voltage it wants to see, it will work.
  • xemodex does not do anything special. They also dont know the correct voltage for these. They modified their VW test bed to work with Gallardo TBs. The procedure you're planning to do is the exact same procedure they do, except they built a testbed to run the TB outside of the car so they can get it done a lot faster.
And yes, these TBs are a 100% failure rate. With enough miles and with enough time, yours will fail, and they arent making them anymore. On a long enough timeline, assuming ICE cars are even still legal, these TBs wont exist. Everybody will have to be rebuilding them to keep these cars going, which is why I wanted to post a detailed write-up. I just know very few people will bother to do it themselves. Most lamborghini owners would rather throw $2000 at xemodex (which, honestly is fine. If you value your time more than your money, thats probably the way to go)
Great post.
I worked with the Volvo throttle bodies and already during the developing phase we had mayor issues with this component.
The big different between the Magneti Marelli and the Bosch throttle body is the complexity. The Bosch only contains an electric motor to move the blade and a touch less position sensor. The MM has the crappy position sensor and a lot of logic for controlling the blade and a CAN controller for communicating with the ECM. And it contains software stored in flash memory. And that’s the main reason why a Volvo throttle body won’t work. The software is completely different.
 
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