Reset ECU.......HELP!!

[darrenmr2]

My 1993 tubby just doesnt seem to be running well...it doesnt seem 'fast'.Before it i had a 1992 tuned 170bhp NA, and was expecting more from the tubby. It has a HKS induction kit, TRUST exhaust and ive just put a Bailey dump valve on it.

Thought i would try resetting the ECU to see if it would sort any running probs out...well i removed 3 fuses in total (1 from the front marked ECU, and 2 from the back, 1 marked ECU the other EFI) then nailed it down the road and it ran poo! Seemed to run well then crap, then well then crap and so on. So i pulled over and did it again (why i dont know! ) This time it seemed a tiny bit better, but ive also noticed the tickover has dropped to nearly 500rpm!

Im really worried ive knackered something, how can i sort it now? Any ideas or suggestions would be great, help me out people please!

[darrenmr2]

Ps- dont know if it makes a difference but ive also just changed dizzy cap and rotar arm and put some champion plugs in!

[Patrick Gray]

should you have drove the car at all never mind hard with the ECU fuses removed.Perhaps i am wrong though.

[Lee @ 3S Service Centre]

you are supposed to remove the fuses for 2 mins. Then replace them.

Then go out and drive the car hard for 10 mins.

It will be tempremental for a while.

Dont worry about a low tickover it will sort itself out after a while of driving.

Lee

[robbie_742003]

Hi, im presuming u replaced the fuses BEFORE u restarted car and nailed it?

[lower]

the procedure is to remove the fuses for 30 seconds or so, replace and then go out and drive the car hard. the idle will drop to 500 rpm for a while until the ecu relearns and the timing resets. i'm assuming you have a rev2

are you running on optimax? are you plugs, dissy cap, rotor arm and leads in good nick? is the bailey dump valve venting to atmosphere or recirc?

these are all the things you need to check to make sure the car produces the power it should.

[darrenmr2]

I am daft sometimes, but YES of course i replaced fuses before driving it hard! I didnt drive it hard for 10 mins though only for a couple. Would doing it again and again damage the car or just be pointless?Anyone local to me fancy meeting to see how my car runs against another tubby cos i just dont know how it should be

[darrenmr2]

Yes am running optimax and ive just replaced dizzy cap rotar arm and plugs! HT leads seem ok as well. Dump valve vents to atmos, makes that cool psssssttttt sound! Should i connect standard one back up? I tried running it standard and performance just seemed the same, so i put the bailey one back on!

[Leon.]

Here's a how to on Jonty's site (hope you don't mind J ):

A core function of the ECU is to keep an eye on fuelling and in addition to the standard map (set by Toyota in the factory) the ECU learns and adapts depending on factors like fuel quality, knocking, and climatic factors. Over a period of time, the ECU may develop a conservative fuelling map which robs the car of performance (or if a problem occurs, e.g. bad fuel or an engine safety scenario.) Although the ECU continually adapts, it's very slow at doing so and can be reset to speed up the process.

Preferably after a drive (and the car now at full operating temperature), park, remove the key, and wait a couple of minutes. In the engine bay is a fuse box -- remove the 7.5A ECU-B and 15A EFI fuses. In the front compartment (not the cabin), remove the 7.5A ECU-B fuse... and then wait for at least two minutes before replacing them. With the fuses re-seated you can start the car and go for a drive, and being already warmed up you can drive the car hard if you wish (showing the ECU exactly how it should be fuelling!)

Don't be alarmed if the car is sluggish at first -- the ECU has been reset and is having to learn from scratch. If it's reset when the car is cold, the lack of performance and hesitation will be more noticeable, but will still pass after a good 10-15 minute journey where the throttle can be exercised.

[darrenmr2]

Thanks for the help i think i will try it again on a motorway so i can drive it for longer after resetting ECU Cheers

[raptor95GTS]

Here's a how to on Jonty's site (hope you don't mind J ):

A core function of the ECU is to keep an eye on fuelling and in addition to the standard map (set by Toyota in the factory) the ECU learns and adapts depending on factors like fuel quality, knocking, and climatic factors. Over a period of time, the ECU may develop a conservative fuelling map which robs the car of performance (or if a problem occurs, e.g. bad fuel or an engine safety scenario.) Although the ECU continually adapts, it's very slow at doing so and can be reset to speed up the process.

Preferably after a drive (and the car now at full operating temperature), park, remove the key, and wait a couple of minutes. In the engine bay is a fuse box -- remove the 7.5A ECU-B and 15A EFI fuses. In the front compartment (not the cabin), remove the 7.5A ECU-B fuse... and then wait for at least two minutes before replacing them. With the fuses re-seated you can start the car and go for a drive, and being already warmed up you can drive the car hard if you wish (showing the ECU exactly how it should be fuelling!)

Don't be alarmed if the car is sluggish at first -- the ECU has been reset and is having to learn from scratch. If it's reset when the car is cold, the lack of performance and hesitation will be more noticeable, but will still pass after a good 10-15 minute journey where the throttle can be exercised.

its not a learning ecu as such more of a clsoed loop constantly tweaking unit

it has an optimum ignition map that it tries to run but if the knock sensor aint happy then the ignition is retarded until no more knock is detected If it gets a big enough jolt it will hold the ignition back permenantly, I can feel this on my rev3 turbo

If it really gets a kicking the ecu will shut the VSV completely hence the safe boost mode which is 3 psi less than full.

Pulling the fuses just forces the ecu to loose all reference points and thus run the optimum ignition map and boost settings. Once you are up and running it goes back into closed loop monitoring and does the ignition advance / retard as the sensors tell it