Dark_Sub_Rosa

Two days now I have noticed this.... here is a quick rundown

The only settings I have changed are the fuel on the HVT side of +50% throttle

In first gear, the other day in traffic I was under 50% throttle so its running stock ecu settings, then I gunned it at about 6k rpm and the car acted like it was limited for a second before it did anything else. I thought maybe I just bounced redline since I was in traffic and couldn't look down at my tach.

This morning, I was coming through a light that has a slight curve to it, I again was around upper rpm range but under 50% throttle and again I nailed it and the car hesitated and threw me forward again before engaging again.

My theory on this is that when I punch it is when the ecu signal is interrupted for the fuel correction as the throttle goes over 50% and the VAFC tries to lean it out, but for whatever reason it doesn't go into it smooth and for whatever reason the car just takes a complete crap on me for a split second before going anywhere.

Any input on this would be appreciated. I'm gonna make some phone calls today because if this is something I can't do without the car crapping out for a second then I'm selling the VAFC and buying a different ECU or something.

Gernby

What are your Lo / Hi throttle settings? Are they 10% / 50%? If so, change them to 80% / 81% and reset the ECU.

ImportSport

Sounds like a problem between the drivers seat and the steering wheel

Dark_Sub_Rosa

Yea, I'm running 10% and 50%, I havnt made any changes to the Lo side only the Hi side. I'll change it to 80% and 81% and see what happens. Any reason though because regardless it's at 100% throttle when the problems occurs.

Gernby

The problem with running 10% / 50% is that the V-AFC is making fuel corrections at varying degrees while the ECU is in closed loop. The ECU tries to compensate for the "flaky" MAP signal, which causes it to run crappy. I had the same symptoms before I raised my throttle settings high enough to guarantee that the ECU would be in open loop.

Gernby

You will need to reset the ECU, or it will take a while for the symptoms to go away.

Gernby

The unmatched fuel corrections would only cause issues at the VTEC engagement point, and even then it would only occur if the VTEC point was lowered significantly.

The problem here sounds like it occurs when there is a rapid throttle transition from partial to full.

Dark_Sub_Rosa

Gernby is exactly on the money with that one..... I'll try the reset tonight and give it the ol heave ho on the throttle and see if it does it again. Thanks and I'll update

Dark_Sub_Rosa

[QUOTE]Originally posted by hecash

Gernby

Good point, but when I had my V-AFC, I never messed with the unmatched settings. I just set them to -2 / -2 based on something I read here. However, I had serious driveability issues (hesitation, stalling, hiccups, etc.) when I had my throttle settings at 10 / 50. Resetting the ECU would fix it for about 4 days, then the symptoms would start again. Once I raised the throttle settings to 80 / 81, it ran perfect.