Unique, unsolvable vtec problem!


M

Matt6288

New Member
Joined
May 20, 2013
Messages
30
I have a ej9 with a b16a ( from del sor sir )with p30 ecu and my problem is i start from cold, drive for as long as i want and i will never get vtec even when up to running temp but if i then stop, turn off engine and restart, vtec works as should for rest of journey!
I have no fault codes, oil level is correct, coolant full, solenoid works fine with power put direct to it.

I have no idea what it could be???

Thanks in advance
 
My guess is a sensor has gone dodgey somewhere, what I would do is start it from cold, take readings from all the sensors involved with vtec. Then once it gets warm take them again.
Then turn car off and start again, retest all sensors and see if one has changed since being turned off.
Might be a massive waste of time but that's what I'd try
 
probably a distributor fault as alot of sensors are in there that make the vtec engage tbh if its only that whats wrong i would just live with it unless its a cheap fix
 
Thanks for replies, is there anything inside dizzy thats replacable other than coil??
Might have to live with it if ecu :-(
 
my mate used to have the exact same problem with his eg6, you could try splicing the earth coming off the solenoid to the blue wire which comes out of one of the green plugs in the loom (excuse my retarded explanation if you pm me I can give you a more detailed view)

Im not to sure how you would do this on a obd2 loom if thats what you are using.
 
I had something similar with my car after I did the B18 swap. Turned out there was excessive resistance in the coolant temp sensor signal wire to the ecu, which was fooling the ecu into thinking the car was at around 60 degrees coolant temp (vtec engagement temp) so it wouldn't always go into vtec, even when warm.
A new wire was run for the temp sensor and its been spot on bet since

Might be worth having a look at that :nice:
 
could be ecu related if the car is working correctly once you turn it off and on. maybe not getting the right signal off one of the sensors?
 
Plugs my ethos in to car tonight and was watching live data whilst driving and coolant temp was surging between 30 and 60 degreess ish, think im on to something??
 
Matt6288 said:
Plugs my ethos in to car tonight and was watching live data whilst driving and coolant temp was surging between 30 and 60 degreess ish, think im on to something??
Click to expand...

Did you turn the car off and on again and check the temp sensor again?
Defo sounds like its the temp sensor is dodgy or not reading correctly for some reason.
 
All sorted!! Bad wire between coolant temp sensor and ecu, replaced and vtec engages properly, every time.
Thanks for all the help
 
You must log in or register to reply here.
Back
Top