ECU reverting back to normal after sometime??

[quicksilver7]

Hello tuner sifu-sifu

Want to ask for your advice. I heard from someone that a piggyback ECU would revert back to it's original settings after 30k to 40k thus resulting in a loss of power and the person recommended me to go for ECU remapping instead.

How true is it and has it happened before? The ECU in topic is unichip and the car is a Lancer.

Thank you, appreciate your feedback!

 

[ixeo]

the unichip won't revert, but the STFT and LTFT of the stock ECU will change over time, and the adjustments done by piggyback won't tally anymore as the fuel from the ECU is different from before. however, if the piggyback was done after the STFT & LTFT sort of settled..then it won't drift that much..but once you remove battery and stock ECU loses the STFT & LTFT..then you'll be out of tune for sure.

if ECU remapping is available, that should always be your first choice as nothing beats the stock ECU..other than very very advanced standalones...like the Cosworth Pectel SQ6..that's about RM12k for the standalone and you don't need it unless you compete in races or time attacks...

 

[pangyau]

How about other aftermarket ECU such as Haltech, Apexi PFC & Motec (standalone type)?
Do we need to trim/alter/adjust the Fuel Trim (Short/Long) once awhile?
Even no other additional/modification done after the 1st tuning...
Seeking an advice & sorry for out off topic a bit...

 

[quicksilver7]

the unichip won't revert, but the STFT and LTFT of the stock ECU will change over time, and the adjustments done by piggyback won't tally anymore as the fuel from the ECU is different from before. however, if the piggyback was done after the STFT & LTFT sort of settled..then it won't drift that much..but once you remove battery and stock ECU loses the STFT & LTFT..then you'll be out of tune for sure.

if ECU remapping is available, that should always be your first choice as nothing beats the stock ECU..other than very very advanced standalones...like the Cosworth Pectel SQ6..that's about RM12k for the standalone and you don't need it unless you compete in races or time attacks...

Thanks ixeo for the good and clear explanation!! Is that also why ECU remap is equally as expensive as a piggyback setup?

I'm unclear about what you mean with "but once you remove battery and stock ECU loses the STFT & LTFT..then you'll be out of tune for sure", it doesn't mean that the stock ECU will lose it's settings (after a remap) if the battery is removed right?

 

[Izso]

the unichip won't revert, but the STFT and LTFT of the stock ECU will change over time, and the adjustments done by piggyback won't tally anymore as the fuel from the ECU is different from before. however, if the piggyback was done after the STFT & LTFT sort of settled..then it won't drift that much..but once you remove battery and stock ECU loses the STFT & LTFT..then you'll be out of tune for sure.

if ECU remapping is available, that should always be your first choice as nothing beats the stock ECU..other than very very advanced standalones...like the Cosworth Pectel SQ6..that's about RM12k for the standalone and you don't need it unless you compete in races or time attacks...

That's a bit worrying. So after I spend RM350 to tune, if the battery dies off I need to retune?

 

[ixeo]

How about other aftermarket ECU such as Haltech, Apexi PFC & Motec (standalone type)?
Do we need to trim/alter/adjust the Fuel Trim (Short/Long) once awhile?
Even no other additional/modification done after the 1st tuning...
Seeking an advice & sorry for out off topic a bit...

Those are standalones.. you won't have any issues with it (with the right tuner).

Thanks ixeo for the good and clear explanation!! Is that also why ECU remap is equally as expensive as a piggyback setup?

I'm unclear about what you mean with "but once you remove battery and stock ECU loses the STFT & LTFT..then you'll be out of tune for sure", it doesn't mean that the stock ECU will lose it's settings (after a remap) if the battery is removed right?

I don't know how much ECU remap costs, but if that option is available it will always almost be better than piggybacks, as it makes full use of all available diagnostics and sensors that came with the car. sorry Toyota no remap for you

yes the stock ECU will lose its settings if battery is removed.

That's a bit worrying. So after I spend RM350 to tune, if the battery dies off I need to retune?

basically you gotta understand how STFT & LTFT works.. STFT makes real time changes based on the stock narrowband o2 sensor.. if its not stoich, the STFT will act immediately to keep it at stoich, in closed loop that is. when the changes done by STFT exceeds a certain limit as defined by the factory, it will store that change in the LTFT. in open loop ECU don't make changes based on o2 sensor anymore, it sprays fuel based on the factory map+LTFT.

usually if you did a tune after your ECU has settled down.. and the battery dies, the ECU would lose the settings. theoretically you should drive around with the piggyback unplugged until the ECU tunes its STFT and LTFT back and plug the piggyback back in.

easier way is get an OBD-II reader and check the STFT & LTFT.

I might be wrong by the way, after all I'm just a pirate with a boat.

 

[holydevil]

oh? if i unplug my battery, my unichip will need to retune again?

 

[ixeo]

the unichip won't lose its settings (AFAIK), but the stock ECU will.

 

[quicksilver7]

Thanks for all the tip offs! Any good Mivec tuners you know/recommend?

 

[ixeo]

I don't know any tuners for cars. Tuners for boats got, I know some pirates off the coast of Philippines But MIVEC not popular among us pirates, we prefer YAMAHA power. Afterall, Toyota & Lexus also ask Yamaha to tune their top of the line engines for them.

I heard of this place called GT Auto I think they have the fastest Evo in Malaysia. 8 second car wor.. I watch movie also Brian O'Conner's Supra only 10 second. Should be good enough to tune your MIVEC kua.