Vtec Problems
 

Hey Honda-Tech Members!

I have recently built a ls/vtec engine in my 95 integra ls.

My problem is my vtec wont turn on when it is supposed to and i have a few ideas why but i wanted to see which one was correct, or if there was an idea i didnt think of.

So the car is running a OBD2B wiring harness thoughout the car and engine bay, then it has a xencron harness which converts it to obd1 to my p28ecu. There is a wire coming out of a4 for vtec from the xencron harness and also there is a wire in the original harness which is green/yellow which is supposed to be the vtec solenoid wire, but there is no plug in the engine bay for vtec, so i sliced into the green/ yellow wire and wired it strait to my vtec solinoid and it still doesnt turn on, so my question is what is wrong? i found a green/yellow wire which goes into one of the giant plugs in the engine bay, but no wire that comes out of it, so i didnt know what the problem is. I am also having idle issues while the engine is warming up, and i read this may have somthing to do with the IVAC system

Let me know what u guys think, here are some pics of what i am working with:

http://s904.photobucket.com/albums/ac247/JDMjackyboy/


Thanks!

Re: Vtec Problems
 

Hmm, isn't there a VTEC pressure switch on the USDM cars? Even if you're using the JDM VTEC solenoid, the ECU may be expecting the switch. You might look here for a bypass: https://honda-tech.com/forums/acura-integra-6/jdm-vtec-pressure-switch-bypass-2278725/

If that's not it (perhaps your ECU is JDM) - there may be a temp requirement also, so make sure the engine's up to temp and that your temp sensors are wired and working correctly.

FYI - Mark

Re: Vtec Problems
 

make sure you have oil reaching the head's vtec assemby viathe bypass, check if the pressure is good enough. My P28 didnt check for VTEC oil pressure switch

Re: Vtec Problems
 

check for the CEL codes

Re: Vtec Problems
 

o sorry i forgot to add my p28 ecu is bypassing the pressure switch becuase, im using the jdm vtec solenoid, why check engine light is not on, but there is a light on that the original owner cut out of the dash, this car has alot wierd going on with it so im sorry if things arent esactly up to snuff.

is it possible to check cel codes without the CEL actualy lighting up?

ive tried to hit vtec when the engine is completly warm with the temp being just below half.

let me know thanks! il try to keep figuring it out, and maybe i should just buy a new obd1 wiring harness or somthing? thanks

`jack

Re: Vtec Problems
 

still cant figure it out

Re: Vtec Problems
 

would vtec not engage if the oil pressure switch was not hooked up? not the vtec oil pressure but just the regular oil pressure switch.

Re: Vtec Problems
 

bump!

Re: Vtec Problems
 

bump!

Re: Vtec Problems
 

please help!
bump

Re: Vtec Problems
 

I think the earlier advice is the best - get the codes. Figure out which wire is CEL and hook up a bulb directly to read the codes if you have to..

Re: Vtec Problems
 

Update:

So i went to try to read the codes but the CEL code reader was un able to connect.
Could this be becuase im using obd1 ecu and obd2b cel code hookup plug? Any ideas? thanks alot!

Re: Vtec Problems
 

Is she warmed up b4 your trying to make her scream? That will make a difference..with mine at least..

Re: Vtec Problems
 

yeah all warmed up has idle problems seems like a vaccum leak but i dont know, i heard it could be a problem with idle control valve or somthing, and vtec wouldnt turn on, i wish i could figure out why i cant check the CEL Codes. Any idea why i wouldnt be able to check the codes?

Re: Vtec Problems
 

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/how-pull-cel-d4-srs-abs-codes-code-lists-1901557/

use this method

Re: Vtec Problems
 

There is no actual CEL on, and i know it should be on becuase my o2 sensor is completly broken off, so is it possible to check what codes the the ecu is throwing without the light actually being on? and why isnt the light on!?

please help

Re: Vtec Problems
 

First thing to do is to check why your CEL is not on with your o2 broken off. Take off your cluster to see if the bulb itself is dead or not. Then from there use the paperclip trick to jump your CEL.

Re: Vtec Problems
 

you should have a black wiring coming from your vtec solenoid too. cut the cover around the black wire and ground it. than it should work.

Re: Vtec Problems
 

if you need pictures than go to google and look for it. it should be there.

Re: Vtec Problems
 

well the bulb is not dead becuase when i first turn the ignition it comes on then imediatly turns off. i thought vtec solinoid only had one wire? and then the vtec pressure sensor which i dont need has the ground and the wire that goes to ecu? if thats incorrect let me know! thank u for all the replys!

Re: Vtec Problems
 

no you need to ground your black wire form the vtec solenoid.

Re: Vtec Problems
 

there is no black wire coming from my vtec solinoid becuase i have a jdm vtec solinoid, meaning there is no vtec pressure switch which has the ground wire? i dont understand what u mean, there is only one green wire coming from the vtec solinoid no other wires. i took that wire and ran it to my ecu with a speaker wire and spliced into where the wire for the vtec solinoid is. is this not right? and how do i take apart my dash with being able to put it back together?

Re: Vtec Problems
 

bump

Re: Vtec Problems
 

please help car needs to get running right!

Re: Vtec Problems
 

bump

brakes are starting to fade, dont know if this has to do with vtec not working and idle problems. still cant read codes