Re-setting the ecu

Post by **Ali** » 12 Dec 2005 06:35 pm

Just wondering if anyone knows if there's any point in resetting the ecu and how to do it? Not sure if its worth doing but I know your meant to do it on newer cars as they "learn" for themselves but I pressume the jetronic doesn't do this? Thought it might be worth doing now i've done the air filter and exhaust?
cheers
Ali

Post by **Chris_C** » 12 Dec 2005 06:59 pm

As the jet-tronic is completely passive IRC, then no, fraid not mate, as the thing doesn't learn at all, it has all the settings 'built in'. I'm not sure where that schematic is that I was on about earlier to you, but I'm sure there is no 'learning' capacity in the system.

Edit: just found this one, it's LE.. but for a Beemer, is it the same system with a few values changed does anyone know? (not that this has values on it anyway...) http://www.carsoft.ru/avtorepair/lejetr.pdf

Post by **pettaw** » 12 Dec 2005 08:57 pm

looks fairly promising Chris. I've got a spare I gutted for the connector for my MS project, so I could trace the circuit I suppose, but tbh I just don't have the energy atm.

Post by **Chris_C** » 12 Dec 2005 09:16 pm

Nah, not worth it

I remember you posted a schematic when you were sorting out your idle (or someone else did...) but I think it's safe to assume it's completely passive.

Post by **jtbo** » 12 Dec 2005 10:51 pm

Easiest mod would be to water temp sensor, ecu thinks that it is colder than it really is and gives more fuel, that equals to more power too

Post by **RandomHero** » 12 Dec 2005 11:07 pm

The ECU can't think and learn indeed, but it can pretty much recover itself after changes. So resetting won't do much.

Post by **Tero Huikko** » 13 Dec 2005 07:11 pm

jtbo wrote:Easiest mod would be to water temp sensor, ecu thinks that it is colder than it really is and gives more fuel, that equals to more power too

umm...how? I mean the mod is made? Will it double the fuel consumption as a 'bonus'

Post by MJ » 13 Dec 2005 08:03 pm

I'm guessing the fact it "gives more fuel" means that fuel economy won't be significantly improved

Post by **jtbo** » 13 Dec 2005 10:05 pm

Tero Huikko wrote:
jtbo wrote:Easiest mod would be to water temp sensor, ecu thinks that it is colder than it really is and gives more fuel, that equals to more power too
umm...how? I mean the mod is made? Will it double the fuel consumption as a 'bonus'

Naturally fuel consumption increases, you just need to install resistor to temp sensor lead so ecu sees that there is more resistance and more resistance is commonly colder temp. What value resistor needs to be is something that is needed to test, you could measure resistance when engine warms up to get idea of resistor range, some have reported that potentiometer is handy too.

Best power comes when air/fuel mix is around 12,6:1 when engines are tuned for near 14.7:1, best economy was around 15-16:1, whole secret of more power is changin air/fuel ratio to 12,6:1.

It won't make miracles, maybe 1-10hp, I have not much idea, only what I have played with my Megasquirt and I have found out that it is around 10hp between that rich mixture and normal, but I have K-cam, maybe gives more power when compared to milder cam when running 12,6:1. Also I have no idea if I have been 12,6:1, 13,6:1 or 11,6:1 but defineatly it gives more power when you put more fuel.

Post by MJ » 14 Dec 2005 03:49 am

Basically pull the choke out a tad, right

Post by **SteveP** » 14 Dec 2005 10:18 am

Choke on an injection car?

Post by **jtbo** » 14 Dec 2005 11:58 am

MJ wrote:Basically pull the choke out a tad, right

Basicly yes, but with fuel injection that is bit better as you see that with carb choke will not let 2nd throat(eh, right word?) open and also restricting air flow to 1st throat of carb, now with fuel injection you just get more fuel without restrictions

Have you heard from EVRY mod for Tdi engines? Principle is very much of same

Post by **Tero Huikko** » 14 Dec 2005 12:32 pm

I've got a K cam in my B200F...might be worth a while putting a potentiometer there and test it. Thanks...

VDO air/fuel ratio gauge on the extra gauge panel and a potentiometer in front of it....mmm

Will the mod affect the gauge in the instrument panel? Does it show also too cold?

Post by **jtbo** » 14 Dec 2005 01:08 pm

Tero Huikko wrote:I've got a K cam in my B200F...might be worth a while putting a potentiometer there and test it. Thanks...

VDO air/fuel ratio gauge on the extra gauge panel and a potentiometer in front of it....mmm

Will the mod affect the gauge in the instrument panel? Does it show also too cold?

There is separate temp sensor for instrument panel gauge and ecu, so make sure you mod right one

Post by **RandomHero** » 14 Dec 2005 05:23 pm

Many ECU mods will help a bit, but you get indeed a higher fuel consumption.

With such a mod, you can trick the mass air flow meter so the engine's ECU 'thinks' he gets more air, so he will inject more fuel.

My uncle has a company called 'car&utilties'. He sells and installs diesel tuning boxes in cars. These are only for diesel cars, but what they do is make the fuel pressure higher so the injectors spray their fuel better making a better combustion butt achieving this with less fuel. So the power increases and the fuel consumption decreases.

Believe me, this really works! It's not like all the garbage you see on ebay and else.