I am tuning my boost fuel tables using Crome and I have a question for you guys. I have my crossover set at 4800. I can hear the high cams actually change at around 4300 but I think the fuel map does not actually kick in until 4800. This is based on the fuel table changes I make and the resulting changes in AFRs. Also, I datalogged the vtec on/off switch from the ECU and it appears to be switching at 4800 or maybe even higher. What I don't understand is that I can actually hear the cams switch around 4300. When I baby it and let it rev up slowly, I know for sure that the cams are changing around that RPM range.

Anyone ever run into anything like this?

Thanks!

 

vtec wont engage sitting still unless you tell it not to check the vss. vtec wont work unless the solenoid receives a signal from the ecu. you set vtec at 4800 and your ecu puts out a vtec signal at 4800, then vtec is 4800. are you hearing the wastegate open or something else.

 

how are you referencing 4300?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dbiker207 &raquo;</TD></TR><TR><TD CLASS="quote">vtec wont engage sitting still unless you tell it not to check the vss. vtec wont work unless the solenoid receives a signal from the ecu. you set vtec at 4800 and your ecu puts out a vtec signal at 4800, then vtec is 4800. are you hearing the wastegate open or something else.</TD></TR></TABLE>

It is definately the Vtec crossing over, no mistaking it. Even at part throttle, not in boost so wastegate is not opening.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by steven_highet &raquo;</TD></TR><TR><TD CLASS="quote">how are you referencing 4300?</TD></TR></TABLE>
My AVCR which is using the tach output of the MSD.

 

Just got back in from checking again. I was datalogging off the ECU and the RPM matched my AVCR and Tach. I took a slow RPM climb from 4000 to 5000. I am 100% positive that the Vtec cam is changing at around 4300 RPM. The datalog showed the vtec on at 4800, where it is set in Crome. Also the AFR are getting lean from about 4200 to 4800 then go slightly rich after that. This makes me think it is actually changing the cam starting at 4200 but still reading off the low cam map from 4200 to 4800.

Is this possible?

BTW, I have an LS/VTEC and had to add two wires to the ECU plugs and spliced them into the vtec solidoid and pressure switch.

 

Anyone ever run into this?

 

So you are logging the VTEC sol BTW, I have an LS/VTEC and had to add two wires to the ECU plugs and spliced them into the vtec solenoid and pressure switch.
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major shoot in the dark here.. but maybe your vtec pressure switch could be switching your sol on/off? Just looked at the wiring schematic and it looks possible!!

Are you logging WOT pulls?

on a side note, I just clicked on my crome icon and got an "Application Error". gotta love it.

 

Are you running a VAFC as well?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2point2 &raquo;</TD></TR><TR><TD CLASS="quote">
major shoot in the dark here.. but maybe your vtec pressure switch could be switching your sol on/off? Just looked at the wiring schematic and it looks possible!!</TD></TR></TABLE>

So maybe I am getting my pressure switch and solonoid wires mixed up? I would think that would be throwing a code or something.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xenocron &raquo;</TD></TR><TR><TD CLASS="quote">Are you running a VAFC as well?</TD></TR></TABLE>

No, I am using Crome.