uh oh.......CEL!

after a mild highway run out to melody drive in on friday night my cel came on. did a ghetto reset (battery pull) and shit was fine. it popped up again today after a few minutes so i reset it with the scan tool. it was code 1259-vtec system malfunction. after i reset it i pulled vtec through third gear no problem? i'm gonna start with an oil change tomorrow, maybe the viscosity is shot, and it has seen quite a few redlines on this oil change. all my wiring connections check out. ive never had a vtec selinoid or oil pressure sensor go bad so i dont know if its an intermittent or one time failure. anyone know how to test these components, or have any other ideas?
fyi-
y7 bottom
y8 head and intake
98 vtec ecu
modified wiring harness
intake and header
not much else that would affect this....

I'd look for corrosion on the vtec solenoid connection, as far as testing the solenoid - I don't know of any way to test it but putting a known working one on if you or someone you know has one layin around

something else just came to me too, since the solenoid works on oil pressure, like you said the oil may be getting weak and the solenoid may be having issues with getting the correct pressure

Here is how VTEC works...

The VTEC system activates the VTEC solenoid valve by command from the engine control module (ECM)/powertrain control
module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that switches valve timing between
Low and High. The ECM/PCM monitors oil pressure conditions in the hydraulic circuit of the VTEC mechanism according to
the VTEC oil pressure switch downstream of the VTEC solenoid valve. If there is a disparity between the oil pressure condition
in the hydraulic circuit that is determined by the ECM/PCM command and the oil pressure condition that is determined by
the status of the VTEC oil pressure switch, the system is considered faulty, and a DTC is stored.

couple quick checks for the oil pressure switch are checking the continuity between the 1 & 2 terminals, if there is continuity the switch is bad, if no continuity is present check for voltage to ground on terminal 1 (blu/blk) there should be battery voltage present, if not check for a short to ground between the switch and the pcm.... for the solenoid check the resistance to body ground should be anywhere from 14-30 ohms. if not the solenoid is bad. that is the majority of the electrical troubleshooting. everything from that point on is pressure testing and what not. low oil will throw this code. not weak oil.

hope this helps.

^^thanks alot fabricator. i was close to figuring it out on my own but im no mechanic by any stretch of the imagination. really appreciate you sharing knowledge.

No problem..

smocha77
i have a ? for you im runnin a d16y7 block and y8 head too i have it in a 94 civic sedan which calls for no knock sensor and the y7 uses one should i wire it in or not to make my vtec work i already got the vtec selinoid and the oil pressure sensor hooked up. im running a p06 ecu that is chipped and chipped for vtec but i dont think my vtec is working. i read that that if the knock sencor is disabled that vtec wont work need help and info thanks guys!!!

i believe the knock sensor is needed. this head swap was my first adventure in motor work and i got most of my info from d-sereis.org. i got my sensor on ebay for 3-4 dollars. are you getting a check engine light? vtec will not engage if you are. but even when mine does, its barely noticeable.
here are a few helpful links:
http://www.d-series.org/forums/diy-forum/140156-d16y7-d16y8-using-stock-wiring-harness.html
http://www.jdmuniverse.com/forums/how-tos-tutorials/32971-d16-mini-me-swap-write-up.html

have you taken the vtec selenoid off to see if the screnn is clogged?
and if the ecu you are using is looking for a knock sensor and you dont have one that could also be your problem