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-   -   HELP PS9 1 wire vtec (https://www.homemadeturbo.com/engine-management-10/help-ps9-1-wire-vtec-30349/)

stolle Nov 22, 2004 12:07 AM

HELP PS9 1 wire vtec
 
i have a ps9 ecu running TE i have enabled vtec, but the problem is the pin a8 is always at 11.8V until i reach my vtec rpm it jumps to 13.9V i was told i had to install a pull-down resistor to get the voltage down to 0V and then it would work properly (0V-13.9V) is this right and how do i do this...
thanks, shawn

mycrx Nov 22, 2004 02:45 AM

Re:HELP PS9 1 wire vtec
 
ya someone help me out by helping him out please? this is a good question.

Chris Harris Nov 22, 2004 09:48 AM

Re:HELP PS9 1 wire vtec
 
I'm not sure...I searched quickly but couldnt find anything.

I did see one guy that the voltage was reading ~2.5v before and ~12v after the VTEC and he made no mention of a pull down resistor.

All you can do is try and see and report back. Part of the development process.

stolle Nov 22, 2004 06:13 PM

Re:HELP PS9 1 wire vtec
 
ok, so i installed a resistor im not sure if its correct, but this is how i installed it.
G=ground, 10k=resistor, A8=A8, vtec=vtec solenoid

G-------10k---------|
|
A8------------------|-----------------vtec

this got the voltage from 11.8V-13.9V to 6.5V-13.9V i have yet to test with it actually plugged into the vtec solenoid cause i wanna try and get the voltage down more ill test it out and tell you guys how it goes.

stolle Nov 22, 2004 06:19 PM

Re:HELP PS9 1 wire vtec
 
that diagram looks like crap but i think it gets the idea across...

mycrx Nov 22, 2004 07:19 PM

Re:HELP PS9 1 wire vtec
 
hey bro where did u buy the stuff to do that and how did u i need to do that also?

Chris Harris Nov 22, 2004 08:29 PM

Re:HELP PS9 1 wire vtec
 

Originally Posted by stolle
ok, so i installed a resistor im not sure if its correct, but this is how i installed it.
G=ground, 10k=resistor, A8=A8, vtec=vtec solenoid

G-------10k---------|
|
A8------------------|-----------------vtec

this got the voltage from 11.8V-13.9V to 6.5V-13.9V i have yet to test with it actually plugged into the vtec solenoid cause i wanna try and get the voltage down more ill test it out and tell you guys how it goes.

I dont think the VTEC solenoid will activate until it sees close to 12 volts so with that 6.5v you should be fine.

Your VTEC point might be off though from what you set it at so you will have to play and see if what you set it at = what actually happens.

BTW, could you send me your BIN file as it is? I'd like to take a look at it if I could

chrisharris@-------------

stolle Nov 22, 2004 08:32 PM

Re:HELP PS9 1 wire vtec
 
this works, adding the resistor brought the voltage down to 6.5V as soon as i plugged the wire into the vtec solenoid voltage dropped to 0 and back up to 13.9V when i hit my vtec engagement rpm...

things i did to accomplish this:

acquired PS9 ecu from junkyard $10.00
28 pin socket radio shack $2.49
10K resistor free found in my dads radio ;D
willem eprom burner $?.??
coralife uv lamp AF913 $35.00 (for erasing eproms)
27C256 eproms $4.00/chip 4 chips
endless hours reading forums and searching for usefull info
Turbo Edit v2.0.11
BasemapHelper.xls, stable.bin, stockpm7.bin from xenocrons website

if neone else has ne questions just ask i will try to answere or direct you to were you can find some answeres

tranceminister Nov 22, 2004 08:37 PM

Re:HELP PS9 1 wire vtec
 
Nice job and good find. I think it cleared the way for alot of other people in the future as well :)

stolle Nov 22, 2004 08:48 PM

Re:HELP PS9 1 wire vtec
 
i hope i did help a lot of people cause this was agrevating trying figure this out thanks to Tinker_Tim over at pgmfi.org for telling me about the pull-down resistor this stuff is F'n sweet...

xenocron i sent you my bin file...


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