Ecu Re-program/replace?

Chris0628 · January 4, 2010

Hi Guys,

some of you might remember ....I have an Civic 2000 Exi (Automatic with the D15Z4 Engine). Not much power but it's supposed to be very fuel economical. But mine isn't. So i took it to the agent and a few other experts to check what the issue was & finally the agent plugged the Diagnostic Computer & did a full check.

They said the Injectors are opened for too long (when idling it should be around 2.7 - 3.1 ms) but mine is around 3.5 - 3.7 ms and there is nothing that they can do....

What are my options ???

MkX · January 7, 2010

check this if you can find any valuable infor

Injector Latency explained

I think this topic needs to be addressed for everyone that is tuning their own cars or is getting E-tunes. This is a very, very important aspect of tuning that needs to be put out there. I have a basic idea on how to do this but there are a few guys on here that know a lot more than me and I'm hoping they will chime in here and add.

First and explanation of what exactly the latency is. Injector latency is one of a few terms used for the time it takes for the injector to actually open and close from the time it's energized to the time it's de-energized. Some other terms used are dead times, offset or battery compensation. I prefer dead times because that is the most accurate description of what is actually happening. Now the dead times will change as fuel pressure rises or drops but with our cars in closed loop the fuel pressure will remain constant so this isn't an issue until boost is added. Now the injector is nothing but a magnetic coil solenoid that when energized will open a valve to allow the pressurized fuel to spray out. When the coil is energized it will take a little time until the injector actually opens. This is called dead time. But this is only half the story. There is also a closing time. This the time that it takes for the injector to close when it is de-energized. These times are extremely important to the fueling of the motor.

Now with the FlashPro we adjust fuel based on injector pulse width. The values in the cells is the time the injector will open for that rpm or load. This is called pulse width. Here is some info I got from the InjectorDynamics site.

When a fuel injector is doing its job on a running engine, it is not held in the wide open, or static position. It is being cycled on and off several times per second. To put this into perspective, a 4 stroke engine running at 9,000 rpm will cycle the injector on and off 75 times in one second. A 2 stroke, rotary, or batch fired 4 stroke engine at the same rpm will cycle the injector on and off 150 times in one second.

To take it a step further, consider this. Using the first example of a 4 stroke engine running at 9,000 rpm, we have only 13.3 milliseconds (13.3 thousandths of a second!) to open the valve, deliver fuel, and then close it again. If we want to give the injector some breathing room, and run it at say 90% duty cycle, we now have only 12 milliseconds to complete the operation.

This is no small feat, and as you probably guessed, the injectors response under these conditions is far from perfect.

It is this imperfect response that leads us to terms like dead time, recovery time, minimum repeatable pulse width, linear operating range, etc.

Now with that said we go back to the FlashPro and how it fuels the motor. I said it used pulse width to control how long the injector stays open. Now say the injector takes 1.2ms to open, dead time, and we need 4ms, pulse width, of fuel at 7k rpms, we will need a total time of 5.2ms to get the proper pulse width to deliver the proper amount of fuel at that time. The dead times setting will add that 1.2ms to whatever value you have in the cell in your cal to make sure you are getting the proper pulse width from your injector. Now in FP manager it is called latency. Entering 1.2ms in the latency tables at the proper voltage it will add 1.2ms across the entire map to make sure that the injector is opening and closing for the full time to make sure you are getting full use of your injector.

Now you say, "well can't you just compensate by adding that time in the map since I'm tuning for my target AFR anyway?" Well yea, but when it comes time for closed loop operation the ECU is counting on you having the dead times set properly. With the ECT compensation tables and IAT compensation tables the ECU will adjust for these settings by shortening or lengthening the pulse width. Now if the dead times aren't set properly the correction may be off enough to cause lean or rich conditions. Now in closed loop it's the same principle. The ECU will see a STFT of 10% so it will cut the pulse width by a certain setting that would cut 10% fuel. Now that setting is a predetermined value that is based on the fact that the dead times are correct. What will happen is if the dead time is off by say 1ms the the fuel will over correct or under correct in whichever direction the dead time is off. This will result in constant searching and unstable idle and closed loop fueling. This will result in awful MPG and inconsistent cranking and just plain weird operation. The other aspect of the tune that will be effected by incorrect dead times is altitude changes. If you are at sea level when tuned and you drive through a higher altitude your vehicle will compensate by removing fuel. If the dead times are incorrect you will have a lean or rich condition and possible issues.

So now I hope you understand this a little more after my post and this helps you all with this subject. I don't have the exact method to tuning the dead times, or latency, but there are a few guys on here that do know and it would be great if they would add to this for us. I will be switching to the ID 1000s soon and they actually come with the values to be entered so I won't have to "tune" them. But 99% of you out there will and should do this to make sure your tunes are consistent in all weathers and altitudes.

http://www.8thcivic.com/forums/hondata/189...-explained.html

http://www.injectordynamics.com/dynamic-ch...terization.html

Edited January 7, 2010 by MkX

Chris0628 · March 24, 2010

check this if you can find any valuable infor
Injector Latency explained

I think this topic needs to be addressed for everyone that is tuning their own cars or is getting E-tunes. This is a very, very important aspect of tuning that needs to be put out there. I have a basic idea on how to do this but there are a few guys on here that know a lot more than me and I'm hoping they will chime in here and add.

First and explanation of what exactly the latency is. Injector latency is one of a few terms used for the time it takes for the injector to actually open and close from the time it's energized to the time it's de-energized. Some other terms used are dead times, offset or battery compensation. I prefer dead times because that is the most accurate description of what is actually happening. Now the dead times will change as fuel pressure rises or drops but with our cars in closed loop the fuel pressure will remain constant so this isn't an issue until boost is added. Now the injector is nothing but a magnetic coil solenoid that when energized will open a valve to allow the pressurized fuel to spray out. When the coil is energized it will take a little time until the injector actually opens. This is called dead time. But this is only half the story. There is also a closing time. This the time that it takes for the injector to close when it is de-energized. These times are extremely important to the fueling of the motor.

Now with the FlashPro we adjust fuel based on injector pulse width. The values in the cells is the time the injector will open for that rpm or load. This is called pulse width. Here is some info I got from the InjectorDynamics site.

When a fuel injector is doing its job on a running engine, it is not held in the wide open, or static position. It is being cycled on and off several times per second. To put this into perspective, a 4 stroke engine running at 9,000 rpm will cycle the injector on and off 75 times in one second. A 2 stroke, rotary, or batch fired 4 stroke engine at the same rpm will cycle the injector on and off 150 times in one second.

To take it a step further, consider this. Using the first example of a 4 stroke engine running at 9,000 rpm, we have only 13.3 milliseconds (13.3 thousandths of a second!) to open the valve, deliver fuel, and then close it again. If we want to give the injector some breathing room, and run it at say 90% duty cycle, we now have only 12 milliseconds to complete the operation.

This is no small feat, and as you probably guessed, the injectors response under these conditions is far from perfect.

It is this imperfect response that leads us to terms like dead time, recovery time, minimum repeatable pulse width, linear operating range, etc.

Now with that said we go back to the FlashPro and how it fuels the motor. I said it used pulse width to control how long the injector stays open. Now say the injector takes 1.2ms to open, dead time, and we need 4ms, pulse width, of fuel at 7k rpms, we will need a total time of 5.2ms to get the proper pulse width to deliver the proper amount of fuel at that time. The dead times setting will add that 1.2ms to whatever value you have in the cell in your cal to make sure you are getting the proper pulse width from your injector. Now in FP manager it is called latency. Entering 1.2ms in the latency tables at the proper voltage it will add 1.2ms across the entire map to make sure that the injector is opening and closing for the full time to make sure you are getting full use of your injector.

Now you say, "well can't you just compensate by adding that time in the map since I'm tuning for my target AFR anyway?" Well yea, but when it comes time for closed loop operation the ECU is counting on you having the dead times set properly. With the ECT compensation tables and IAT compensation tables the ECU will adjust for these settings by shortening or lengthening the pulse width. Now if the dead times aren't set properly the correction may be off enough to cause lean or rich conditions. Now in closed loop it's the same principle. The ECU will see a STFT of 10% so it will cut the pulse width by a certain setting that would cut 10% fuel. Now that setting is a predetermined value that is based on the fact that the dead times are correct. What will happen is if the dead time is off by say 1ms the the fuel will over correct or under correct in whichever direction the dead time is off. This will result in constant searching and unstable idle and closed loop fueling. This will result in awful MPG and inconsistent cranking and just plain weird operation. The other aspect of the tune that will be effected by incorrect dead times is altitude changes. If you are at sea level when tuned and you drive through a higher altitude your vehicle will compensate by removing fuel. If the dead times are incorrect you will have a lean or rich condition and possible issues.

So now I hope you understand this a little more after my post and this helps you all with this subject. I don't have the exact method to tuning the dead times, or latency, but there are a few guys on here that do know and it would be great if they would add to this for us. I will be switching to the ID 1000s soon and they actually come with the values to be entered so I won't have to "tune" them. But 99% of you out there will and should do this to make sure your tunes are consistent in all weathers and altitudes.

http://www.8thcivic.com/forums/hondata/189...-explained.html

http://www.injectordynamics.com/dynamic-ch...terization.html

Thanks... this article helped a lot in understanding the issue with my car..... i got it tested & the exact issue mentioned in this article exists.... the fuel injectors are open for too long (pumping out more fuel than required) and hence the low fuel economy....

Now the question is.... what do i do..... the agents recommendation was to replace the ECU.

GearHead · March 24, 2010

Thanks... this article helped a lot in understanding the issue with my car..... i got it tested & the exact issue mentioned in this article exists.... the fuel injectors are open for too long (pumping out more fuel than required) and hence the low fuel economy....
Now the question is.... what do i do..... the agents recommendation was to replace the ECU.

Not sure if this would help, but have to tried resetting the ECU?

Chris0628 · March 24, 2010

Not sure if this would help, but have to tried resetting the ECU?

yes machan.. tried that & did a reading yesterday.. same injector timing....

KI4120 · March 24, 2010

yes machan.. tried that & did a reading yesterday.. same injector timing....

I think you have to re write the fuel map in the ECU...that requires ECU re-programming system.

Zakie will save ur day...!!! PM me if u need his contact number...

Chris0628 · March 24, 2010

I think you have to re write the fuel map in the ECU...that requires ECU re-programming system.
Zakie will save ur day...!!! PM me if u need his contact number...

i did try him.. he said to a VTEC conversion... which i cannot afford.....

shanX · March 24, 2010

i did try him.. he said to a VTEC conversion... which i cannot afford.....

around how much? <_<

Chris0628 · March 24, 2010

around how much?

100 to 110 k

evergreen · March 24, 2010

100 to 110 k

is this for an engine swap?

Chris0628 · March 24, 2010

is this for an engine swap?

don;t think so.. might be a header ...etc replacement.....

Bugatti · March 24, 2010

don;t think so.. might be a header ...etc replacement.....

100k just for a header...??!! :blink: damn..!

Chris0628 · March 24, 2010

100k just for a header...??!! damn..!

think he said for the full job... including ecu also... didn't get all the info since im not going for a conversion

just wanna get the prob i have now sorted...

GearHead · March 24, 2010

think he said for the full job... including ecu also... didn't get all the info since im not going for a conversion
just wanna get the prob i have now sorted...

PM Sent

Chris0628 · March 25, 2010

PM Sent

thanks for the contact machan.. i called him & he said he needs to have a look first... so hoping to meet him tomorrow...

vl keep you guys updated on the progress ....

isurujosh · March 25, 2010

did u check with vasant too?

bdw how is ur gear box now?

evergreen · March 25, 2010

did u check with vasant too?
bdw how is ur gear box now?

thought he changed the gearbox.

isurujosh · March 26, 2010

thought he changed the gearbox.

i have not been in touch with the forum over the past few weeks, so i don't know the latest. but last i heard from him was that his gb issue was sorted.

Chris0628 · March 26, 2010

The latest is as follows....

Gearbox..... it was running smooth for abt 1 week after Vasant did a flush & changed the ATF... but the harsh shift is back...also when the A/C is on.. the car feels very heavy.....

ECU..... after all the injector cleaning, throttle body cleaning, fuel system cleaning....etc... i did a OBD2 scan... same Injector Pulse width.... so i guess what's left is to Replace both ECU & AT

evergreen · March 26, 2010

The latest is as follows....
Gearbox..... it was running smooth for abt 1 week after Vasant did a flush & changed the ATF... but the harsh shift is back...also when the A/C is on.. the car feels very heavy.....

ECU..... after all the injector cleaning, throttle body cleaning, fuel system cleaning....etc... i did a OBD2 scan... same Injector Pulse width.... so i guess what's left is to Replace both ECU & AT

just an idea...you dont like a manual conversion?

Chris0628 · March 26, 2010

just an idea...you dont like a manual conversion?

..... did have a EG8 Manual... best car i had so far...... conversion... Details, Cost, & how will it affect when im selling the car someday ?

evergreen · March 26, 2010

..... did have a EG8 Manual... best car i had so far...... conversion... Details, Cost, & how will it affect when im selling the car someday ?

i dont think the conversion will have any effect when it comes to disposal as long as the mechanics who does it does the job in a style. i have seen a couple of ek 3s converted to manual. but brother it will not be cheaper than your vtec conversion. only advantage is you will have years of trouble free running.

http://6thgearadvertising.com/civic-hx/

just follow the above link and you would see the whole lot of details of a manual conversion.

Chris0628 · March 26, 2010

i dont think the conversion will have any effect when it comes to disposal as long as the mechanics who does it does the job in a style. i have seen a couple of ek 3s converted to manual. but brother it will not be cheaper than your vtec conversion. only advantage is you will have years of trouble free running.
http://6thgearadvertising.com/civic-hx/

just follow the above link and you would see the whole lot of details of a manual conversion.

Thanks for the suggestion but don't think i wanna go down that path

by the way...does this model have a O2 sensor & where is it exactly ?? (2000, EXi - D15Z4 Engine)

evergreen · March 26, 2010

Thanks for the suggestion but don't think i wanna go down that path
by the way...does this model have a O2 sensor & where is it exactly ?? (2000, EXi - D15Z4 Engine)

no idea on this particular engine. anybody else out there to help?

shanX · March 26, 2010

Thanks for the suggestion but don't think i wanna go down that path
by the way...does this model have a O2 sensor & where is it exactly ?? (2000, EXi - D15Z4 Engine)

Why not, as you're planing to change the transmission and ecu anyways

I guess, probably one on the exhaust manifold and sometimes another on the exhaust after the catalytic converter