i was just wondering if anyone had problems with thier Vtec kicking in when driving their car when its cold at one bar. When i first got my s2k i realized everytime i started my car and hit 7000 RPM my engine would just stop at that RPM and the car would hold back. My friends dont really seem to have that problem. Does anyone else have this problem? if not whats wrong with my car.

 

yes it's a safety feature in case someone tries the dumb idea of redlining their car while the engine and fluids are not up to operating temp.

it's not a problem, it's a feature. and it probably saved you from destroying your engine.

EVERY S2000 has this feature. if you're friends cars don't do it, it's because they are already at operating temp (which the ECU considers 140 degrees fahrenheit on the coolant)

 

If your friends' cars are not S2000s, that only means that their manufacturers don't think it's such a big deal because they don't have 11:1 compression and a 9000 rpm redline.

 

There are 3 'interlocks' which must be met for ANY vtec to work.

Forget it, I'll just post this..........

Honda introduced the first VTEC system on the Acura NSX in the early 1990s and installed it in the Civic 1.6 liter in 1992. There are several versions of the VTEC system, so I will explain how the standard VTEC system operates.

In the standard VTEC system, the engine design uses VTEC technology to vary the lift and duration of the intake valves to provide optimum performance at low and high rpm. In a standard engine, most manufacturers use a camshaft profile that makes a compromise between the ideal valve lift and duration for best low rpm performance and peak performance at high rpm.

When the camshaft profile is too radical, it allows compression to be lost at low rpm when the air speed is insufficient to take advantage of the high lift camshaft. That is why a racing engine will run poorly at low rpm and is not practical for everyday driving. Also, an engine with a mild camshaft profile does not allow sufficient time to fill the cylinder with fuel and air at a high rpm, which can cause the engine to have poor top-end performance. With a VTEC system, the engine will have both types of camshaft profiles.

The VTEC system uses a lower lift camshaft for normal engine operation. When it gets between 4,000-6,000 rpm (depending on year and model), it electronically turns on the VTEC system and the high-lift camshaft lobes are used, creating better top-end performance. This system allows optimum power in both low and high rpm.

The basic VTEC engine uses a camshaft with three intake lobes for each cylinder. The outer two camshaft lobes are for low rpm operation - they operate the intake valves directly by rocker arms. The center high-lift camshaft lobe and its rocker arm are idling and the movement is controlled by a spring, or what Honda calls a "lost motion" assembly.

When driving the vehicle with the rpm high enough for VTEC operation, the engine control module (ECM) operates the variable valve timing solenoid to open the solenoid and allow oil pressure to be applied to the pistons in the intake rocker arms. This action causes the outer rocker arms to be pinned to the middle rocker arm and now the three rocker arms operate as a unit, using the high-lift camshaft lobe for improved high-end power. When the engine rpm drops below VTEC operation, the VTEC solenoid is not energized and hydraulic oil pressure is turned off. This allows the return spring to return the pistons to their rest position and lets the rocker arms operate independently again. The VTEC transition between low and high rpm is smooth and normally not felt by the driver.

The ECM also looks at other inputs for VTEC operation - engine temp, engine oil pressure and vehicle speed (VTEC does not turn on unless the vehicle is moving). A separate oil pressure switch monitors the VTEC system. If a problem occurs, the ECM can turn off VTEC operation and will set a code, turning on the "check engine" light. In some cases, it can also cause a driveability problem.

The VTEC oil pressure switch is a normally closed switch. The ECM sends a voltage to the switch and expects the voltage to go through the switch to ground. If the ECM reads a voltage on that circuit when the VTEC system should not be operating, it will turn on the "check engine" light and set a code. This code will be a P1259 on a vehicle with OBD-II.

When the ECM energizes the VTEC solenoid valve to turn on the VTEC system, the ECM expects the VTEC oil pressure switch to open and see the voltage on the circuit. If there is a delay with oil pressure opening the switch, the ECM will set a trouble code and may limit fuel delivery, causing a driveability problem.

Reasons for no VTEC operation include low engine oil level, VTEC solenoid not opening or the screen behind it is restricted, an engine that has low oil pressure, or an oil pressure leak to the rocker arm assembly. In some cases, when engine work is performed, a missing or damaged O-ring can cause incorrect oil pressure to the VTEC system.

 

How many times have you tried hitting vtec before 3 bars on your temp gauge? Ouch - your poor S...

Not too good for it when the rev limiter kicks in... Please, please read your owner's manual.

 

 

i figured it was cuz it wasnt at three bars. i only did it once when i got the car last year. after that i knew not to do that.

 

OUCH...arent people smart enough not to revv the piss out of ANY engine if it has not reached operating temperature? So much for long term reliability.

 

Unfortunately, 'bling' is the priority of many owners. They can't be bothered with knowing a few mechanical aspects and limitations of their machines. Some people never read the owner's manual...... but hey, they look good.

 

Just a thought, but how come you can rev over 6000 when out of gear at a standstill if you have to be moving to engage VTEC?