Gain setting issue -HFS-3

[leman_opc]

Richard, I'm _possibly_ having an issue with my gain potentiometer not having any effect on the injection pattern.

From my brief tests today it looks like medium potentiometer setting results in 1:1 ratio of FAV duty cycle to fuel injectors duty cycle (which I think is OK) and another 90 degrees clockwise potentiometer setting results in 1,5:1 gain ratio, but further turning the gain potentiometer clockwise results in gain ratio DECREASE.

I'm also unsure whether my results with 90 degrees clockwise turn are OK - I thought it would be more like 2,5:1 gain ratio with such setting since I think I read somewhere on the forums here that maximum gain is 4:1 and 90 degrees clockwise is pretty close to maximum setting (maximum is 135 degrees clockwise on mine).

Too bad I didn't check which duty cycle HFS-3 sees (my results above are based on fuel injectors duty cycle calculation as logged from ECU), will do it on Sunday when I have access to the car.

But assuming I will be able to reconfirm the problem with gain setting above what would be my next steps? Is it likely that the potentiometer itself could have failed or something?

[Richard L]

The trimmer life is limited to ~50 turns. It is rarely needs re-trimming after the fuel- IDC to water-idc ratio is set.

I am not sure what is happening. It is most likely as you said, the track is worn to excess. I can post you a spare, it will take approximately 30 days to Russia.

[leman_opc]

Thanks for your prompt response / replacement suggestion Richard!

Due to sh!t weather I decided to skip testing whether the contorller sees the fuel IDC properly today, instead I measured the gain trimmer pins resistance with a multimeter (I'm not good in electornics so I'll explain in layman terms ))) The trimmer has 3 pins, when turning the knob clockwise resistance between one pair (lets call it central-left) reduces from 10 kOhm to almost 0, resistance between the other air (central-right) increases from 0 to 10 kOhm respectively.

On a first glance looks like a normally working potentiometer to me - so maybe my flow issues are not due to cotroller in the end... Are the resistance values I observed OK?

I will go on testing how the controller sees the fuel IDC tomorrow if the weather will be better.

[leman_opc]

My next guess is actually that I have my pump failing once again and not producing enough pressure in the line - when I have my jet out of the intake in SYS mode I get 7 bars all the time with SC trimmer set as it is now, on a real road test I get only 4-5 bars but then it is when it's 1 bar excess pressure in the intake. I doubt such a difference could be when the actual pressure in the line is 160 psi as the pump is rated for, but if the actual pressure is lower for some reason - then could be IMO...

[leman_opc]

I was able to reconfirm that the controller sees the IDC normally today.

I also managed to get a linear progressive injection by setting the gain trimmer in default 1:1 position.

I can't imagine an easy way to test the pump pressure, but I'm almost 100% sure the meth injection works as supposed.

My original issue with an observed decrease in flow with gain increased was probably due to 100% FAV duty cycle already reached pretty soon on gain trimmer set both 90 degrees cw and 135 degrees cw (so actually almost no difference in these settings) and a occasional flow decrease noted.

Just for my better understanding - could you pls. confirm Richard that I got it right re. max gain setting (x4 to the actual IDC)? I can't find now where I got it from originally...

[Richard L]

The gain trimmer is is for re-scaling IDC, not for increasing flow. To increase flow , you need to increase the jet sizes.

You need to observe the 95% dc led on the controller. It is be just "lit" and no more.

[leman_opc]

Fully understood, but my injectors IDC is currently only 70-80% max. so I wanted to re-scale IDC to get 100% FAV duty on that level by adjusting gain (I know that kinda defeats the idea of proportional meth/fuel flow but still).

I first tried the system in SYS mode and set SC trimmer so that it showed 7 bars with 100% FAV duty. Then I tried to get the same result on the road with jet already in the intake by adjusting gain but got only 4-5 bars with the same SC setting.

I jumped to the conclusion that I fail to set my IDC gain so that FAV is 100% open on 70-80% injector duty. But that was probably wrong as the decrease in flow was not due to FAV duty cycle but due to intake pressure being 1,5 bar excess at max flow vs. 0 bar excess during the SYS test. That's how I see it now...

Too bad I didn't think of looking for 95% dc led. Do I read it correctly that 95% dc means 95% dc of the FAV and not 95% IDC seen by the controller?

For my future mapping / system setting could you please let me know what is the maximum gain setting? Is it x4.0 as I initially thought?

[Richard L]

95% means the FAV is reaching its mechanical max, not electronically. There are valve lantency to put into the calculation.

I believe you have taken the FAV apart and reassembled it without valve lift calibration. For this reason, you have completely changed the characteristics of the electromechanical property of the valve.

Ideally, you should send the FAV back to me to be recalibrated.

[leman_opc]

???

Why do you think so?

I didn't disassemble FAV apart from the steps needed to install the kit (restrictor installation etc). And it actually looks like my kit is working perfectly fine right now...

Maybe my previous message was a bit misleading. I don't have 95% led on all the time, I just meant I could use it to verify my FAV duty reaches 100% on my max IDC (instead of tracking flow and comparing it to the flow I got during SYS test) - as you mentioned above.

[Richard L]

I must have mistaken you for someone else. My apologises. (It was softic from Moscow)

OK, ignore my previous comments. Good to know every thing is workong fine.