Question for the EFI pros on injector pulse time : V-Twin Forum: Harley Davidson Forums

ViennaHog · 08-29-2007, 02:02 AM

Gents:

analyzed several data runs of my 2007 Ultra stage 1 and looked in particular at the injector timing.
AFAIK injector opening time controls the actual amount of fuel injected. The required amount of fuel is calculated from the AFR target value and the individual VE data for each cylinder at a given load/rpm/map.
It is my understanding that a higher VE value requires a higher amount of fuel which in turn results in a longer opening time of the injector.
When I look into the data, I can see that the rear cylinder very often shows a shorter injector opening time than the front cylinder with the VE for the rear cylinder being significantly higher than the front VE. This observation is valid for closed loop and open loop operation.
At the same time I can see significant timing retardation up to 12 deg at the rear cylinder at operating temperature across a wide rpm and load rate.

Something fugged up here?

PS I can supply run data via e-mail

BVBOB · 08-29-2007, 05:00 AM

I asked the very same thing last spring and never did get an answer, I have not noticed the timing issue as drastic though, just the pulsewidth, like you, I have observed my VE' s, corrected VE or mapped VE values higher (rear)with injector pulse width sifnificantly lower than the front. It's almost like the Data mode had the front and rear injector pulse width numbers labeled backwards. My thoughts are as long as what's coming out the cylinder into the exhaust is correct, I am not really concerned what method or numbers it takes to get there but I would really like to hear about this also if you find an answer.

Totenkopf · 08-29-2007, 06:34 AM

BV,
I thought we had this figured out. I rationalized that it had to be the data was reversed in the data mode display and you verified it with twinscan in realtime mode.

What am I missing here?

Vienna, it has to be the same thing. Do you have access to a twinscan?

**HDWRENCH** · 08-29-2007, 09:42 AM

Also the rear cylinder only has 315* of timing cycle that the program is based on.

ViennaHog · 08-29-2007, 09:45 AM

Quote:

Originally Posted by Totenkopf

BV,
I thought we had this figured out. I rationalized that it had to be the data was reversed in the data mode display and you verified it with twinscan in realtime mode.

What am I missing here?

Vienna, it has to be the same thing. Do you have access to a twinscan?

No, I don't have access to it. I do have an older -2006 scanalyzer that may or may not give me the pulse time.
Can soembody please check stored data runs preferably done with version 4.62 of the SERT?

TIA

Totenkopf · 08-29-2007, 12:39 PM

I have a lot of data from v4.53 and it is correctly associating higher or lower VE with a higher or lower pulse width with either cylinder

Here is the link to the previous post by BVBOB on 4-12-07.

http://www.v-twinforum.com/forums/sh...d.php?t=103257

You might want to try the Scanalyzer into the '07 and see what data, if any, you get. I don't think it will hurt anything.

ViennaHog · 08-29-2007, 01:13 PM

Thanks for the link, exactly like my question. It appears that the problem started with version 4.60. I hope it's the only data confusion. Anybody a used TwinScan II 4 sale?

CROCKETT_ · 08-31-2007, 07:44 PM

I have been looking for some threads with reference to the Twin Scan II.
It seems that it would problably good topic for a new thread but...
I hope you dont mind me jumping in here. I was hoping i could find someone (that knows more that me) to take a look at my Twin Scan Data. Just to see if anything jumps out that looks like it could use some fine tuning. The bike runs fairly well i would say although it seems it could use a little more in the top end.

GPO03FatBoy · 09-01-2007, 04:14 PM

Quote:

Originally Posted by CROCKETT_

I have been looking for some threads with reference to the Twin Scan II.
It seems that it would problably good topic for a new thread but...
I hope you dont mind me jumping in here. I was hoping i could find someone (that knows more that me) to take a look at my Twin Scan Data. Just to see if anything jumps out that looks like it could use some fine tuning. The bike runs fairly well i would say although it seems it could use a little more in the top end.

No expert here, but these are some thoughts. First, the file would be much more useful with O2 data. Tough to tell much about the tune without it. That said, the first thing that jumps out is that your timing looks backwards through a portion of WOT in that from 3000 to 4300 rpm the rear cyl is advanced a .5 degrees beyond the front. Ordinarily TC's like the reverse. I guess the bottom line is a dyno tune would tell better, but it caught my eye. And your AFR command looks pretty rich at WOT (calling for 12.6 at 2800 rpm, down to 12.4 at 5700). At about 20% throttle the AFR call is very lean, at 15.

Also, don't drop the throttle on your 3rd-4th power shift! That sec of throttle drop during the shift cost you 1325 rpm drop. You can get it to 100 quicker than that!!

CROCKETT_ · 09-14-2007, 10:35 AM

Quote:

Originally Posted by GPO03FatBoy

No expert here, but these are some thoughts. First, the file would be much more useful with O2 data. Tough to tell much about the tune without it. That said, the first thing that jumps out is that your timing looks backwards through a portion of WOT in that from 3000 to 4300 rpm the rear cyl is advanced a .5 degrees beyond the front. Ordinarily TC's like the reverse. I guess the bottom line is a dyno tune would tell better, but it caught my eye. And your AFR command looks pretty rich at WOT (calling for 12.6 at 2800 rpm, down to 12.4 at 5700). At about 20% throttle the AFR call is very lean, at 15.

Also, don't drop the throttle on your 3rd-4th power shift! That sec of throttle drop during the shift cost you 1325 rpm drop. You can get it to 100 quicker than that!!

I aggree that the O2 data would make all the difference. I am trying to do my best without it for now. As for the timing data you may be right although i have seen similar numbers on several machines i have taken data from with techno research, power commander and even with stock ecm. I do not have enough experience to try to explain this. As far as AFR Command and the Inj PW, timing, etc, i have seen several differences between the different machines with the data i have collected up to this point. One thing I would like to know is, does the power commander make its changes before of after the Twin Scan Data is recorded ?

I agree on your statement in regards to the power shift although this run was for data purposes only. I did get a good laugh out of it though

Thanks for the reply

GPO03FatBoy · 09-14-2007, 12:29 PM

Quote:

Originally Posted by CROCKETT_

I aggree that the O2 data would make all the difference. I am trying to do my best without it for now. As for the timing data you may be right although i have seen similar numbers on several machines i have taken data from with techno research, power commander and even with stock ecm. I do not have enough experience to try to explain this. As far as AFR Command and the Inj PW, timing, etc, i have seen several differences between the different machines with the data i have collected up to this point. One thing I would like to know is, does the power commander make its changes before of after the Twin Scan Data is recorded ?

I agree on your statement in regards to the power shift although this run was for data purposes only. I did get a good laugh out of it though

Thanks for the reply

The clutch comment was obviously for the humor factor. Couldn't resist!

My comments were just general in nature based on your data, one of the real experts may have some more insight. To me the bottom line on the timing is that it should be set at what the bike likes. Taking a look at knock threshold is one way to get a feel. The dyno is another good tool. Harley's preset ECM timing is certainly not optimal, it just runs the bikes decently and meets their emissions need. As for the PC III, I understand it to be an add-on. It modifies the signals coming out of the ECM. The TwinScan reads the HD data bus. That would mean that your Twin Scan would not be reading the PC IIIs changes to the ECM's signals (eg. pulse width and timing). You should, however, still be able to read the sensor values (eg. temp, MAP, TPS, knock, etc.). just some thoughts.