Replacing ECU

[FGII-XR6]

does anyone know how to get a replacement ECU to rork without taking it to ford to get ripped off ( they want $80 for what they admitted will take all of 5 minutes that equals $960 an hour i'm in the wrong game)? i am puting an XR ECU in my SR but need to get the BEM to talk to it tried the learn mode from the manual where you leave it on for upto 61 minutes to relearn but no luck any help would be appreciated

[Tech Trainer]

Going by the sounds of it you have a Smart Sheild vehicle.

Find a mechanic who has an up to date scan tool and he should be able to do. The aftermarket have been able to do the "handshake" as they call it for a couple of years now.

I am sorry to inform you that it will not take "5 minutes". Whether they like it or not it will take a minimum of twenty minutes to half an hour. Having said that $80 is about right when you think that dealerships and most workshops have a minimum charge for any work done. This is usually half a hours labour.

[LOWAU]

Maybe try another Ford dealer? if there is any avaliable.

Also let us know how you go after its installed, I always wanted to do this.

[JC]

$80 is not unreasonable.

[xr8ute]

This is a 4.0L i6 right?

Bear in mind, the XR6 had a higher pressure fuel reg than non-XR's. If you where to swap in an XR6 ECU without also adding the XR6 fuel reg, then you will run lean....this is bad.

[FGII-XR6]

Originally Posted by xr8ute

This is a 4.0L i6 right?

Bear in mind, the XR6 had a higher pressure fuel reg than non-XR's. If you where to swap in an XR6 ECU without also adding the XR6 fuel reg, then you will run lean....this is bad.

I have been told this by quite a few people but according to ford service ford parts and the parts database on this site there is only the one fuel reg for all I6 engines i have looked at the one on an XR6 with the HP engine and it was also the same don't get me wrong if you know differently i would appreciate any part numbers you have so I can go to my ford dealer and get what i need but to date all points to the one reg

[AUXRVIII]

Engine at idle I6 pressure is 225kpa, I6HO pressure is 250kpa.
Engine off I6 275kpa, I6HO 300kpa.

[b2tf]

GlennBA did this to his old AU and hit problems with the fuel regulator,solution was to get an XR fuel rail.

[FS5]

Originally Posted by au3xr6

I have been told this by quite a few people but according to ford service ford parts and the parts database on this site there is only the one fuel reg for all I6 engines i have looked at the one on an XR6 with the HP engine and it was also the same don't get me wrong if you know differently i would appreciate any part numbers you have so I can go to my ford dealer and get what i need but to date all points to the one reg

i have seen both the standard and xr6 regs .standard is 2.7 bar /xr6 is 3.5 bar.
mind you i ran a xr6 motor with its 3.5 bar reg on a standard au i6 ecu
and going dy the DTE and black tail pipe it wasn't running lean

[xr8ute]

Originally Posted by FS5

mind you i ran a xr6 motor with its 3.5 bar reg on a standard au i6 ecu and going dy the DTE and black tail pipe it wasn't running lean

XR6 reg with a non-XR computer means it would be running rich

[FS5]

Originally Posted by xr8ute

XR6 reg with a non-XR computer means it would be running rich

sorry to go off track a bit ,but now i have put my old cam back in and the j3,you reckon my my egine might be running a bit rich. considering its now running the xr6 3.5 bar reg and the j3 was tuned to the 2.7 standard au one.


i thought your AFR's were determend by the o2 sensor?

spark/timing maps though???????

[bodes-sh]

the afr's are controlled by the ecu through the o2 sensor, but think about it, a forte ecu has been programmed to run an injector pulse based on a 2.7 bar fuel reg, pump 3.5 bar into it and even if it's running the injectors as short pulsed as possible, it's not allowing for the extra pressure...if that makes sense

[FGII-XR6]

Originally Posted by bodes-sh

the afr's are controlled by the ecu through the o2 sensor, but think about it, a forte ecu has been programmed to run an injector pulse based on a 2.7 bar fuel reg, pump 3.5 bar into it and even if it's running the injectors as short pulsed as possible, it's not allowing for the extra pressure...if that makes sense

this is true but these ECUs are clever buggers if they still see it's lean it will compensate till it gets it right

[xr8ute]

Originally Posted by FS5

i thought your AFR's were determend by the o2 sensor?

The fuel tables in the EEC are used to target a specific AFR at each rpm x load site. It calculates the required pulsewidth based on a known value for injector size (lb/hr), and a calculated value for air mass based on the manifold absolute pressure and the relevant value from the volumetric efficiency table.

e.g. if it calculates there is 100g of air, and the targeted AFR is 10:1, then it will open the injector long enough to give 10g of fuel .

When in closed loop, feedback from the O2 sensor is used to check how close the actual AFR is to the targeted AFR. The result of this feedback is stored in a table that is then used to "correct" future pulsewidth calculations for that load x rpm site.

BUT, not all rpm x load sites are ever used during closed loop running AND the O2 sensor is only narrowband, so it only really knows how close to stoich the mixture was.

So how accurate is it to correct a WOT fuel calculation by X percent, because X was the correction required at idle/cruise?

So the "self-learning" component of the EEC is pretty crude when it comes to correcting many parts of the fuel table used during open loop. It appears as though it was really designed just to make sure the car is running as close as possible to stoich during cruise conditions to keep emissions as low as possible....

The other thing to know, is that corrections do not have to be made at all load sites. There is another table that can be used to switch on/off fuel trims being applied at some or all parts of the fuel table.

I'm not sure I understand it completely enough to explain it very clearly, so I hope the above helps more than it confuses :P

There is some great material on the EEC Tuner, and twEECer forums on the internet. Not to mention the GUFB and CRAI8 strategy documents that where released to the internet a few years ago....well worth a read if your interested.

[xr8ute]

Originally Posted by au3xr6

this is true but these ECUs are clever buggers if they still see it's lean it will compensate till it gets it right

There is a self-imposed limit to the correction that the EEC will apply based on O2 sensor feedback. I suppose to make sure that if the O2 sensor itself fails (and sends radically incorrect feedback), that it doesn't change the fuel mix enough to cause damage the engine.

[FS5]

Originally Posted by xr8ute

The fuel tables in the EEC are used to target a specific AFR at each rpm x load site. It calculates the required pulsewidth based on a known value for injector size (lb/hr), and a calculated value for air mass based on the manifold absolute pressure and the relevant value from the volumetric efficiency table.

e.g. if it calculates there is 100g of air, and the targeted AFR is 10:1, then it will open the injector long enough to give 10g of fuel .

When in closed loop, feedback from the O2 sensor is used to check how close the actual AFR is to the targeted AFR. The result of this feedback is stored in a table that is then used to "correct" future pulsewidth calculations for that load x rpm site.

BUT, not all rpm x load sites are ever used during closed loop running AND the O2 sensor is only narrowband, so it only really knows how close to stoich the mixture was.

So how accurate is it to correct a WOT fuel calculation by X percent, because X was the correction required at idle/cruise?

So the "self-learning" component of the EEC is pretty crude when it comes to correcting many parts of the fuel table used during open loop. It appears as though it was really designed just to make sure the car is running as close as possible to stoich during cruise conditions to keep emissions as low as possible....

The other thing to know, is that corrections do not have to be made at all load sites. There is another table that can be used to switch on/off fuel trims being applied at some or all parts of the fuel table.

I'm not sure I understand it completely enough to explain it very clearly, so I hope the above helps more than it confuses :P

There is some great material on the EEC Tuner, and twEECer forums on the internet. Not to mention the GUFB and CRAI8 strategy documents that where released to the internet a few years ago....well worth a read if your interested.

thanks mate,it looks i'l be doin a bit of searching and reading

[AUXRVIII]

Originally Posted by xr8ute

There is a self-imposed limit to the correction that the EEC will apply based on O2 sensor feedback. I suppose to make sure that if the O2 sensor itself fails (and sends radically incorrect feedback), that it doesn't change the fuel mix enough to cause damage the engine.

Generally the limit is around 25 to 30%. If there is no O2 feedback adaptive tables are ignored, a preset map is used based on other inputs such as engine temp, tps and map sensor.

[FGII-XR6]

well got the ECU in an auto elec charged 45 and i was theter when he did it i was driving away in 15 minutes that included the time it took me to change ECUs ant the parameter reset tested the adaptive shift settings and it changed modes fine better shifts and seems to have a bit more grunt

[xr8ute]

So you've fitted an XR6 ecu to a non-XR6, and you still have the std non-XR6 fuel pressure regulator?

[FGII-XR6]

thats going in tomorrow cam not going in till next week had to order it in

[robbo_yobbo]

I actualy thought it was the fuel pump itself that pumped a higher capacity on the xr vs the forte

[xr8ute]

Originally Posted by robbo_yobbo

I actualy thought it was the fuel pump itself that pumped a higher capacity on the xr vs the forte

A bigger fuel pump will not change the fuel pressure, thats the job of the regulator. The regulator acts as a resistor against the flow of the fuel pump. It blocks the flow (from the pump) just enough to maintain its set fuel pressure. Any excess fuel is diverted back to the fuel tank.

So if your existing fuel pump was already flowing enough, but you then put a bigger one in, all that extra flow capacity would bypass the reg and go straight back into the fuel tank.

[FGII-XR6]

got the cam in. idled like a pig but i did my favourite procedure the ECU reset ( I know some of you think it's a waste of time but did the trick)and runs like a dream. hope to get it on the dyno soon I let you know how it goes

[LOWAU]

What cam did you end up getting?

[FGII-XR6]

genuine XR6 HP cam and the matching ECU with the red back catback extractord and intake it goes heaps better than a standard I6