Hey guys I am new to the site. I have read alot of the forums that you guys post, even before becoming a member and there is all sorts of useful information. I am an avid integra lover and I now own my third. I have a 99 ls that i recently swapped a 94 jdm gsr into. I have one and only one problem, but it is a big one. The motor runs great but I have no vtec, a more than common problem I have come to learn. I am aware that I need to run the vtec wire which i did. I ran vtec from the solenoid to pin A4 on the ecu. After that the motor hit rev limiter at 7grand and still no vtec. I just replaced my jdm p72 with a chipped usdm p28. Now I have no rev limiter, but still no vtec. I want to continue using the p28, but I am wondering if I need a usdm solenoid or if there is any way around my problem with the jdm solenoid. I had been told that I only needed to run the vtec wire and not the oil pressure sensor because it was jdm. Since this I have also learned that I may need an EVAP purge and an RPM sensor. I was hoping that someone may know what I actually need to run and what does or doesnt need to be grounded. I thank you in advance and look forward to chatting with you all.

 

Do you have enough oil? Is your speedometer working?

I was under the impression that the oil pressure sensor must be run or else no vtec. If there is not enough oil pressure than vteec will not engage so you have to have it.

 

need the vtec pres. sens (oil pressure sensor). its two wires... one goes to PCM the other to ground. doesn't matter which one to which. its a simple open/close switch activated by a minimum pressure threshold

if you use the p72, you'll need to add the knock sensor

if you use the p28 you will not need the knock, but you wont have secondary control (the butterflies in that goofy manifold on a gsr).

you need to check for codes. use the unmodified ecu (sounds like the p72 is un modded) to check for codes so you dont get any wacky misleading codes.

this should help you figure it out

 

Hey thanks for the quick reply, I do have enough oil and my spedo is working. I was under the impresion that the oil pressure needed to be run to the D6 pin of the ECU. I dont meen to be ignorant, but im not quite sure what you meen by PCM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 3.504 &raquo;</TD></TR><TR><TD CLASS="quote">need the vtec pres. sens (oil pressure sensor). its two wires... one goes to PCM the other to ground. doesn't matter which one to which. its a simple open/close switch activated by a minimum pressure threshold

if you use the p72, you'll need to add the knock sensor

if you use the p28 you will not need the knock, but you wont have secondary control (the butterflies in that goofy manifold on a gsr).

you need to check for codes. use the unmodified ecu (sounds like the p72 is un modded) to check for codes so you dont get any wacky misleading codes.

this should help you figure it out</TD></TR></TABLE>


Yeah...true story!!!

 

The strangest part of this entire ordeal is that I have yet to throw any codes with the p72 or the p28. No check engine light. Im not sure what you mean by PCM, but once I run that wire and ground the other my problem should be solved? What is the PCM and where? Thanks

 

Do you know if I am able to keep the jdm solenoid using a us ecu?

 

pcm is an obd2 term for ecu

powertrain control module, engine control module, engine control unit.... same diff.

you can use the "jdm" solenoid w/ the usdm computer. a vtec solenoid is a vtec solenoid... in fact a "jdm" is a "usdm" and vice versa.

as far as the pin for the vtec pres. switch: D6 is correct for obd1. if using the p72, you will have to install a wire for the knock sensor. pin D3 is knock. knock sensor is 1 wire. vtec will not work on the p72 w/o the knock.

if i were you, i'd stick w/ the p72 over the p28. a stock motor shouldn't be run on an ecu w/ a map for something else than that motor or some map you dont know.

 

Thank you very much for the help, this is the most useful information have received so far. I am almost positive that I know what wires you are talking about, but just to be certain are you refering to the two that come out of the green plug on the solenoid?

 

solenoid only has 1 wire coming out of it.

the vtec pres switch has a 2p connector right next to the solenoid (same area of the head).

 

Alrite so I wired the vtec pressure sensor and grounded it, but still no vtec. I am still running the chipped p28 so the knock sensor isn't needed. Perhaps it requires an RPM sensor, I am really not sure. Any ideas?

 

I ran the vtec pressure sensor and grounded it, but still no vtec. Do you know if there are any other wires to be run, if not what might my problem be? Still using p28 and also I have a skunk2 IM so no butterflies.

 

you need to check for codes. jump the connector in the passenger kick and count the blinks.


look over your connections to make sure they're good too. make sure the ground you used for the vtec pres. switch is a good ground (no paint underneath it).

you wont need the knock for your p28.

an rpm signal is in the distributor, if you have a working tach, then you have a good rpm sig.

go over all of your electronics one more time. make sure the ecu is good (try it in another vtec car. see if the good vtec car has working vtec w/ that ecu.)

test the solenoid (apply power w/ a fused jumper wire running from B+ to the solenoid, listen for a "click" noise.)

test the switch by starting the engine, then going accross the 2 pins of the connector w/ an ohm meter. you should see 0.03 ohms or less. if you see more than 0.03 it'll usually be in the Mega ohms scale or OL/OFL. this means that for whatever reason, the switch is open when it should be closed. you now have to figure out if you have good oil pressure. if you have good oil pressure, the switch is bad. if you have bad oil pressure... you have a bigger problem than no vtec.