will vtec into a 91 crx work if everything is wired btu the knock sensor isnt hook up because the plug is broke

 

when you first start the car youll prolly have about ten or so seconds until the ecu light comes on, and when that happens, no more vtec.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BluntMan &raquo;</TD></TR><TR><TD CLASS="quote">when you first start the car youll prolly have about ten or so seconds until the ecu light comes on, and when that happens, no more vtec. </TD></TR></TABLE>

Yes, and the solution to that would be to get a ecu that was not equipped with a knock sensor, such as a P28.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BluntMan &raquo;</TD></TR><TR><TD CLASS="quote">when you first start the car youll prolly have about ten or so seconds until the ecu light comes on, and when that happens, no more vtec. </TD></TR></TABLE>
What are you talking about?? The KS doesn't relate to VTEC in anyway, you may lose some power due to the ECU running in safe mode but you're VTEC will still x-over just like normal... Peace

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kataku2K3 &raquo;</TD></TR><TR><TD CLASS="quote">
What are you talking about?? The KS doesn't relate to VTEC in anyway, you may lose some power due to the ECU running in safe mode but you're VTEC will still x-over just like normal... Peace</TD></TR></TABLE>

"Limp home mode is rev limited to 3500 RPM with a fixed ignition and rather rich fuel setting with the engine check light permanently on."
taken from... http://www.hondata.com/techecuanatomy.html

So, if you couldn't go over 3500rpm in "safe mode" or "limp mode" I would imagine there would be no VTEC crossover.

 

i'm pretty sure the KS is one of the variables you need for vtec to cross over....
the P28 will work?!!? and still engage vtec? thats cool but i've never heard of it

 

p.s. i thought P28 was obd1 and a 91 rex is obd0 now i'm all confused

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ryan C &raquo;</TD></TR><TR><TD CLASS="quote">p.s. i thought P28 was obd1 and a 91 rex is obd0 now i'm all confused</TD></TR></TABLE>

I'm confused too now. What motor is in this 91 Rex?
I do know that the P28 is OBDI and also has VTEC, but does not use a knock sensor. It is out of a 92-95 EX. So that should solve the problem.

http://www.hondata.com/ecus.html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ryan C &raquo;</TD></TR><TR><TD CLASS="quote">i'm pretty sure the KS is one of the variables you need for vtec to cross over...</TD></TR></TABLE>
You're car ISN'T running in "limp home mode" if your KS is improperly wired or disconnected... If you don't believe me try it... The ECU will run in "limp home mode" if something is wrong and you'll see it come up if your ROM is NOT soldered in correctly or bad, it'll also come up if you have an improperly wired CKP, CYP, or TDC sensor... As for the P28, you are all right there, it is OBD1 and can be run on a Rex with a nonOBD-OBD1 jumper... I made one and converted my friend Mike's (jdmDXrex) '88 Rex to OBD1...

 

my knock sensor on my b16 was loose and maid the CEL come on but vtec still worked fine. U can have it unpluggled and im pretty shure vtec still works, cause this issue came to me, i just hatted that bright *** CEL, so i tightned the sucker down.

 

if the KS wont affect vtec engagement what will??

 

POSTED BY Adam (Kataku2K3), I'm on Mike's comp and am too lazy to sign onto my name, hehe!!!

The ECU looks for several things... ECT (engine coolant temperature has to be up), VTM (oil pressure has to be up also), engine speed (rpm), VSS (vehicle speed), and there's like three other parameters but I can't think right now... I'll get them up tho... Peace

 

i'm pretty sure KS is one of the parameters

 

Whoa a lot of mis information here!

VTEC will still engage with Knock Sensor Code 23!!

Being OBD0, I am not too sure if it's different, however, having Code 23 WILL still engage VTEC.

I drove around with a broken knock sensor for 2 weeks and was annoying as hell due to running richer and the motor bogging a little bit, but once knock sensor was replaced problems were solved.

 

Yup poison is correct just as I said before... It is the same on a nonOBD car... VTEC is in no way effected by your KS... Pretty simple, Peace

EDIT: I just thought of another... TPS, and when I think of the rest I'll put them up, haha


Modified by Kataku2K3 at 9:12 PM 6/9/2003

 

you guys no more than me but i'm still almost positive that i heard there are 7 parameters for vtec to cross over and the KS is one of them

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ryan C &raquo;</TD></TR><TR><TD CLASS="quote">you guys no more than me but i'm still almost positive that i heard there are 7 parameters for vtec to cross over and the KS is one of them</TD></TR></TABLE>

VTEC will still work with a defictive plug or defictive circuit. However, if there is knock detected, then it will throw it into limp mode. But this hardly ever happens.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by poison &raquo;</TD></TR><TR><TD CLASS="quote">

VTEC will still work with a defictive plug or defictive circuit. However, if there is knock detected, then it will throw it into limp mode. But this hardly ever happens.</TD></TR></TABLE>

Right, so it will not affect VTEC if the sensor is coming up as missing or faulty, but if it detects knock then you will go into limp mode and VTEC will not activate. I was getting confused.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">

Right, so it will not affect VTEC if the sensor is coming up as missing or faulty, but if it detects knock then you will go into limp mode and VTEC will not activate. I was getting confused.</TD></TR></TABLE>

You got it. In limp mode there are not extra services such as VTEC and such. The motor will run richer, timing will be retarded so the motor will not blow.

 

Explain this one then folks, if you can I have a Eurpoean Spec '90 CRX with a B16a, it has NO knock sensor, I run a JDM SPoon N1 PWo ECU with a knock sensor input, the lack of knox=ck sensor was overcome by installing a 1kOhm resistor.

THe CEL comes on sumtimes, VTEC always works!!!

The KS goes open loop after 5000rpm so it won't affect your car on full throttle when VTEC is engaged.

 

on my turbo ls/vtec i didnt have a KS and my didnt work. car ran like **** broke up all to hell at 6500rpms.

 

man...i'm still confused

 

I keep telling you... The KS in no way effects VTEC... Just because you have a solid CEL on DOESN'T mean that your ECU is running in "limp home mode"... It'll bring up a code 23 and maybe effect performance a bit but it doesn't limit your rev to ~3500rpm... If you wanna try something to really believe me do this... Run your car with NO KS then short your SCS to run the code... You'll get 2 long flashes then 3 short ones... This will repeat over and over again unless your have more things wrong then just the KS... Also try reving the car up, it'll go past ~3500rpm all the way up to your rev limit (if you have one)... Now, if you have a chipped ECU, etc. that is socketed this is really easy... Open it up and take out the ROM... Now your car is running off the main microprocessor and whatever sensors you have... This in turn puts the ECU in limp home mode. Short the SCS connector again and see if you get anything... The CEL is solid... Now rev the car up... It's limited right around 3500rpm... Throttle response is shitty and with a VTEC tranny you're probably not going to be too much over 55-60mph on the freeway in 5th before you run into a "rev limiter"... Okay I'm done... Sorry for going on and on and on but the way I see it, it really isn't all that difficult to understand and everyone keeps arguing... hehe Peace

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kataku2K3 &raquo;</TD></TR><TR><TD CLASS="quote">Just because you have a solid CEL on DOESN'T mean that your ECU is running in "limp home mode"...</TD></TR></TABLE>

Very true. I keep pulling a code 14 (IACV) with a solid CEL and the car crosses into VTEC just fine - in fact I think it pulls harder with the code thrown The reason I didn't stop and fix it was I was in the middle of an autocross run As a matter of fact, the car even continues using the O2 sensor with the solid CEL.

The ECU will only run in backup mode - ie safe mode - ie limp (home) mode - if certain CELs are triggered, as Kataku said. It's ENTIRELY possible to have a solid CEL, have the ECU flashing a code, and have VTEC working just fine!

 

i thought u needed to cut jumper J1 to get it to run on main processor with a chipped ecu.