Vtec oil pressure

[SKREMN]

what is the minimum PSI requierments for oil pressure for the vtec to cut in?
mine is cutting in and out I got a pressure guage and it looks like it drops to around the 40 mark once vtec cuts in
around 70 psi before vtec comes on
i noticed i lost about 5-7 PSI when i installed my oil cooler

[Slow96GSR]

Lost psi with the cooler is just the hoses and maybe some air in the lines.

Here is what I found in my books. Bear with me as I am typing what it says in the book.

Testing:
Remove the single pin connector from the VTEC solenoid. Remove the 10mm bolt from the oil pressure test port on the solenoid. Attach the oil pressure gauge. Warm the motor up. Run the motor at 1000, 3000, and 5000 rpm, but do not run it at no load for mare than 1 minute. Oil pressure should be 7psi or less with the solenoid disconnected. Re connect the solenoid and run the same test. It should now be 57psi or more.

The following are used on both systems (VTEC and VTEC-E) to determine VTEC operations by the Engine Management Computer.
-Engine speed.
-Vehicle speed.
-Throttle position sensor output.
-Engine load measured by the MAP sensor.
-Coolant temperature.

Oil pressure really doesn’t determine when VTEC comes on, just whether or not it will come on.

Oil pressure (HOT):
-Idle 10-psi minimum
-3000RPM 50-psi minimum

So if you do not meet that you will not have proper operation of anything.

[tinkerbell]

i dunno the minimum pressure the VTEC pressure switch looks for is...

my oil pressure drops to 60psi when VTEC kicks in, but my base oil pressure is 78psi... (i am installing oil cooler on weekend so will be interested to see any drop)

but 40psi sounds too low, where are you taking the reading from?

[ECU-MAN]

VTEC need 25 to 30 psi to kick in, it wont be reliable unless you have a good 50 to 70 psi.

at idle you will want to have about 15- 30 psi
3000 rpm you would want around 55- 70 psi

[SKREMN]

I'm picking my pressure up from my vtec oil line its a b20
i got a T joint on it
on idel its atleast 15-20 psi and normal driving its up to about 60-70 psi
I think I may pump up my oil pressure a bit on the weekend


Vtec mostly dopes out in second gear after 6500-7000 RPM and the car sounds flat
doesnt happen n first gear

i have treied adding a little oil just 2mm aove the fill line didnt help

[ECU-MAN]

is your sump dented

does your oil pressure fluctuate ???

[ECU-MAN]

btw

the back of the block where the oil pressure switch is isnt the vtec oil line, its the main oil line, if you had tapped into the vtec pressure line ( which is in the front of the motor ) you will not get a pressure reading unless your in VTEC

[SKREMN]

My motor is is 4000K's old and everything is brand new and in perfect condition my sump is fine
the pressure guage fluctuates with rpm and throttle so the guage is fine

[SKREMN]

i have tapped the guage into the main oil line wich is the oil feed for the vtec

[ECU-MAN]

with your engine revving at 3000rpm
does the oil pressure guage hold steady at its pressure or does it move back and forth eraticly

[SKREMN]

is it quite steady at 3000rpm and onwards and doesnt gain pressure untill i let off throttle jumps maybe 2-3 psi and then drops

[Dxs]

is your sump dented

what difference would this make..

and by that do u mean major dents.. not small 1 cm jobs?

[Weq]

dents can ****up the pickup and loose pressure. honda's are better then most. I know a guy with a pulsar, small dent,and lost 30psi!

random idea:

u might wana switch to a thicker oil? you might be running loose clearances which is causing lower the normal oil pressure.

[Slow96GSR]

1: Check the connection between the sensor and the gauge.
2: Try thicker oil.
3: Check pressure at the VTEC solenoid.
4: Check clearances in the pump.

Rotor-to-cover clearance:
-Standard 0.001 to 0.003 inch
-Service limit 0.006 inch

Tooth tip clearance:
-Standard 0.002 to 0.006 inch
-Service limit 0.008 inch

Outer rotor-to-pump body clearance:
- Standard 0.004 to 0.007 inch
- Service limit 0.008 inch

If you need a DIY on checking let me know I have a pump here and already torn down.

5: Check the sump.
6: flush the system for debris.

[Perry]

i know with my gauge when vtec kicks in the guage goes abit crazy then it goes fine again wired =(

[ECU-MAN]

what difference would this make..

and by that do u mean major dents.. not small 1 cm jobs?

yeah what Weq said

small dents should be ok, you would have to be pretty unlucky

[ECU-MAN]

1cm dent would be classed as a big ass dent :)

if thats under the strainer it will gause this...

[tinkerbell]

I'm picking my pressure up from my vtec oil line its a b20
i got a T joint on it
on idel its atleast 15-20 psi and normal driving its up to about 60-70 psi
I think I may pump up my oil pressure a bit on the weekend


Vtec mostly dopes out in second gear after 6500-7000 RPM and the car sounds flat
doesnt happen n first gear

i have treied adding a little oil just 2mm aove the fill line didnt help

i jsut installed my oil cooler,

pressure is now 60-70psi normal driving, around 25psi at idle...

it does not drop out of VTEC, and goes down to 60psi when VTEC kicks in (my sensor is ALSO located on the VTEC oil line coming from the back of the block)

[SKREMN]

ok I just increased my oil pressure now it drops down to 50psi rather then 40psi when vtec kicks in
I have only just driven it once since the change but it didnt drop out of vtec
on normal driving its about 65-70 psi
and idel about 25psi
so we are pretty simular now with our readings

Tinkerbell - have you inccraesed your oil pressure from stock? stock pump? stock tention on the piston spring?

I now have 3 washers on mine

[tinkerbell]

stock tension, stock B20B oil pump (same OEM part as in ITR engine)

i feel that is should be OK if it stays above 60psi (as my old B20VTEC is still runing fine with only 60psi BASE oil pressure)

i have not had a proper chance to test it in full VTEC in higher gears, so will still be watching it carefully...

i believe that the difference between our pressures may be the looser clearances in your "built" bottom end... (mine are factory B20B specs)