Setup:
90 Civic STD Hatch
OBD1 B17A1
P61 ECU

Question:
I do not think my Vtec is engaugeing. I am not getting the noticable harmonic change in the Cams. Is there a way to check the Vtec function?

I have an Autometer tach. Can I run the Vtec tot hte tach to change the engaugement point? If so how do I do this?

 

https://honda-tech.com/zerothread?id=164863

good luck

 

Test the solenoid itself... Run a straight 12vdc+ signal at idle to the solenoid... If your motor bogs down a bit then your solenoid, rockers, and mechanics of VTEC are all fine... If that's the case check into the wiring... Everything connections good??? Is your car warmed up??? You're not just reving the motor right??? Just checking but let us know if you find the problem... Good luck

 

I would not recomend you send a line to the soleniod at idle

what you need to do is grab a multi meter and check the resistance across the two sides of the soleniod

then check it again back at the ecu, those number should be close if not you got a bad connection

if they compare then next step is to get the book and get what the resistance is supposed to be, i have forgotten what it is, but someone should be able to help.

Usually with swaps it ends up being a bad connection

 

Yes, I am driving the car. If all of this checks out then there is most likely a problem in my wiring some place?

 

i would bet money
multimeter and 5 min should tell you

 

If I get a multimeter what shout the votlage read?

 

Just curious.... why would you not recommend it Audipwr1??? It's not hurting anything... Just make sure the motor is warm, etc...
EDIT: You should have a 12vdc signal out... Remember if you are testing this your ECU will be looking for a VSS signal in order for your VTEC to engage... That means the car has to be moving... I see that you're running the P61 so I figure you must be running a nonOBD-OBD1 jumper... To simply test the output you can either probe off the OBD1 point A4 or the nonOBD A8... If you're getting 12vdc there at your VTEC activation point that's good... That just means you most likey have a bad connection or solenoid... As Audipwr1 said testing the impedance across the solenoid should shed a little insight to the solenoids condition... Peace

 

I would just be worried about sufficient oil pressure at idle.

not reading voltage, reading resistance. The vtec soleniod is well a soleniod. A certain resistance (damn me for not rememnbering what it is) shoud be near consitant at all points across the two wires.

With the car off do this, and you should get 0 voltage and a certain resistance, one probe to one wire on the soleniod side other probe on the other wire take note of the resistance, now go into engine cabin, and measure the resistance of the two wires at the ecu. those numbers should match

note once again resistance not voltage is what you are measuring

Helms should have a complete discription on this, but im at school with none of that stuff here, maybe someone can chime in with the good resistance number.

 

Yes I know that voltage is different then resistance... however to test the VTEC output signal from the ECU resistance isn't going to tell you ****... Testing the solenoid itself is when you measure the resistance... You will test over the line in to ground... I'm not trying to be an *** so PLEASE don't take it that way... I'm just giving other options in which you measure voltage instead of impedance.... Latez


Modified by Kataku2K3 at 7:29 PM 4/20/2003

 

oh your right!
for the ecu side you put one probe on the ecu out for vtec, and on the other probe you go all the way to the soleniod

thanks for pointing out my stupid mistake

the correct method i just mentioned will make sure your line from ecu to soleniod is intact

sorry again that was just stupid