1150cc not allowing .25 airflowperrev?

[lil corb]

Just finished installing FIC 1150cc injectors and can not bring my airflowprev to .25 ish. After running the MAF compensation so the car can run right my new 50-100 hrtz sliders are way positive I'm assuming to compensate for more fuel coming in. The problem is now I can't lower those to sliders to bring my airflowperrev down to .25 without the car not running right. I have calculated my global fuel and deadtimes using the calculator.

How would I go about adjusting those sliders to bring it down to .25-.27 and still having the car run right?

FIC 1150cc
walbro 190lph
fuellab FPR
Link V3 lite

Thanks

 

[gofer]

Please post a log, that's one of the advantages of having Link.

 

[lil corb]

I will get one up tmw morning.

 

[boost97gst]

You have aftermarket cams. Bingo... I have crower 272s and drove myself crazy trying to achieve .25. Wasnt happening. I settled at around .34 or .32 i think. Not sure how your cams/fmic/intake/turbo will play into it, but cams i know affect base airflow/rev

 

[lil corb]

Here is a quick idle log. One thing I did notice is the car took a VERY long time for the o2 sensor to start cycling into closed loop. The temps were at 200 degrees before it went into closed loop. That has never happened before I installed the new injectors.

Before the injectors I was able to dial my airflowperrevs to .25 even with the same 272s. I just can't now after the injectors.

I verified base FPR at 37psi.

Any ideas on tune and why it took for ever to enter closed loop? According to ecm wiki everything was good for it to enter closed loop.

 

[eclipsegsx1736]

If your MAF sliders near idle range are very positive after the injector change, it's almost certainly your deadtime being too small. Obviously, airflow does not change with injectors, so adjusting the MAF sliders after an injector change is a bandaid for something else that's changed.

 

[lil corb]

That's interesting. I followed the injector wiki on ecmlink and used the recommended 330 deadtime. After thinking about it., if I am correct, there should of been no change to airflow after the change of injectors as the global fuel change should have adjusted my fuel consuption accordingly.

Any ideas based off of my log on what the problem could be? And why it took for ever to enter closed loop from a cold start?

I did notice that after the injector install my a/f ratio est went to really rich and that's probably why my maf comp template went so positive.

 

[eclipsegsx1736]

That's interesting. I followed the injector wiki on ecmlink and used the recommended 330 deadtime. After thinking about it., if I am correct, there should of been no change to airflow after the change of injectors as the global fuel change should have adjusted my fuel consuption accordingly.

Any ideas based off of my log on what the problem could be? And why it took for ever to enter closed loop from a cold start?

I did notice that after the injector install my a/f ratio est went to really rich and that's probably why my maf comp template went so positive.

The recommended deadtime value is a good starting point, but can vary not only from injector to injector, but also with many other factors such as discrepancies between ECU measured battery voltage vs. injector drive voltage, resistor pack impedance, etc. I've found that in most cases a slight amount of adjustment needs to be made from the base deadtime value, and in some cases the value can be quite far off on some setups.

I can't view the log at the moment, but the ECU waits for a response from the O2 sesnor before entering closed loop. If the sensor takes a long time to warm up, or if the car is running very lean, it will take longer for the O2 voltage to increase to the point that the ECU decides the O2 sensor is working and can be relied on for O2 feedback. Depending on what AFRest you're using, you may need to modify the parameter's properties with the correct injector size and deadtime value so that the AFR is displayed properly.

Beau

 

[lil corb]

The recommended deadtime value is a good starting point, but can vary not only from injector to injector, but also with many other factors such as discrepancies between ECU measured battery voltage vs. injector drive voltage, resistor pack impedance, etc. I've found that in most cases a slight amount of adjustment needs to be made from the base deadtime value, and in some cases the value can be quite far off on some setups.

I can't view the log at the moment, but the ECU waits for a response from the O2 sesnor before entering closed loop. If the sensor takes a long time to warm up, or if the car is running very lean, it will take longer for the O2 voltage to increase to the point that the ECU decides the O2 sensor is working and can be relied on for O2 feedback. Depending on what AFRest you're using, you may need to modify the parameter's properties with the correct injector size and deadtime value so that the AFR is displayed properly.

Beau

Good info! From what I have learned it's good to have a good base of .25-.27 airflowperrevs then start adjusting deadtimes at idle but I can't even get the revs down to there. The only thing I did during the install was disconnect the battery, which maybe I would have to re calibrate my MTX-L?

I can see it not going into closed loop as fast now, if the car is cold and I start the open map has my a/f ratio around 12-13s so I can see it taking sometime to get to closed loop operation. But once again I didn't have this problem until after the injector install.

I'm still confused on why I had to increase my sliders after the install so it run right?

Appreciate everyone's help figuring this out

 

[eclipsegsx1736]

Good info! From what I have learned it's good to have a good base of .25-.27 airflowperrevs then start adjusting deadtimes at idle but I can't even get the revs down to there. The only thing I did during the install was disconnect the battery, which maybe I would have to re calibrate my MTX-L?

I can see it not going into closed loop as fast now, if the car is cold and I start the open map has my a/f ratio around 12-13s so I can see it taking sometime to get to closed loop operation. But once again I didn't have this problem until after the injector install.

I'm still confused on why I had to increase my sliders after the install so it run right?

Appreciate everyone's help figuring this out

How long does it actually take to enter closed loop? Log the parameter "closed loop" instead of just looking at the AFR to determine that time. A value of "1" means the vehicle is in closed loop.

If your low airflow sliders had to increase only after the injector install, it's either because your old injector deadtime was too large, or your new injector deadtime is too small (most likely the latter). This is because the deadtime value is a fixed fuel pulsewidth offset number, meaning it has more "contribution" to the total pulsewidth at or near idle as opposed to cruise or WOT conditions. Due to this, a car with too low of a deadtime setting will tend to run too lean at or near idle and "ok" in other situations. Vise versa, of course, is also true.

Beau

 

[lil corb]

How long does it actually take to enter closed loop? Log the parameter "closed loop" instead of just looking at the AFR to determine that time. A value of "1" means the vehicle is in closed loop.

If your low airflow sliders had to increase only after the injector install, it's either because your old injector deadtime was too large, or your new injector deadtime is too small (most likely the latter). This is because the deadtime value is a fixed fuel pulsewidth offset number, meaning it has more "contribution" to the total pulsewidth at or near idle as opposed to cruise or WOT conditions. Due to this, a car with too low of a deadtime setting will tend to run too lean at or near idle and "ok" in other situations. Vise versa, of course, is also true.

Beau

I do log closed loop and open loop. It switched around 200 degrees to closed loop and while in open loop my a/f was richer than I would like it to be at idle. All this after injector install.

You know what, I think you are on to something with deadtimes. With my stock 450cc (confirmed with part #) my dead times were at 330 just to get my combined fuel trim to 0ish % but I followed everything so far correctly in terms of dialing my airflowperrevs to .25 through mafs. (which had my sliders down by a lot) then adjusted deadtimes to get the combined fuel trim to 0%. Is this not the proper way of doing it?

After putting on the 1150cc, in order to have it run at all. I ran the maf comp at idle and it moved my sliders all the way positive (which is adding fuel) I'm so confused as now I think I was doing everything wrong from the beginning

 

[Calan]

With my stock 450cc (confirmed with part #) my dead times were at 330 just to get my combined fuel trim to 0ish %

If you were adding all that deadtime to stock injectors, then you were inadvertently compensating for an airflow or fueling issue.

 

[lil corb]

If you were adding all that deadtime to stock injectors, then you were inadvertently compensating for an airflow or fueling issue.

Maybe a boost leak somewhere Craig? I thought at first I might have had a N/T FPR so I changed it out and still had deadtimes up that high.

I'll run another boost leak test and double check everything again before trying to figure out this issue.

One quick question though, at idle and cruise, generally, while tuning are the sliders usually adjusted in a positive manor (adding fuel) if you are not stock? If so when are they (generally) adjusted in a negative manor. From seeing the demos on ecmlink, he adjusted the maf sliders from 50-100 hrtz in a negative direction which made me assumed everything was right even though my deadtimes were so high on stock 450cc.