A while back I posted a problem I was having with my Vtec engagement. It began with a engine light, after taking it to the dealer they told me that they would replace the Vtec solenoid because the message was that the Vtec solenoid was bad. They had to order it so I picked up my car and the Vtec did not kick in, duh the Vtec solenoid is bad, but it worked before I dropped it off at the dealer, huh?. Anyways it was replaced and VTEC would not engage, but after 2 days everything went back to normal. Well after a week or two I started to get problems again.

Here is what I was doing : Before the first engine light, I was moving the VAFC around trying to find a place to install it that would be more visible on a weekend and everything was fine, unitl monday morning when the engine light came on while I was putting air in my tires at the gas station. After taking it to the dealer the Vti and Vto signals on the VAFC say off, I completely uninstalled the VAFC and that is when that after 2 days from putting the new VTEC solenoid the VTEC engagement began to work. This past week the VTEC will not engage at first driving ( when the engine is still cold) after a little while of driving the VTEC will engage just fine. I installed VAFC again today and still the result of the Vti and Vto is "off"

Now for the purpose of this topic. Dayum FINALLY!!!!

Now 1) the VAFC may be bad

2) My ECU is bad or

3) The VTEC solenoid is bad.

I would like to know what the peoples ideas are to the problem.

Thanks.

 

check the easy stuff first, oil & pressure

after that remove the V-AFC and see if the vtec engages....as for the ecu, your redline/cut off in the proper range?

 

I already removed the VAFC again, it is getting late and I have DYNO tomorrow did not want it to interfere if it was the VAFC causing the problem. I woudl think the dealer would have checked all that I don't know how they are now. The redline seems to be in the right place I have taken up to 8K yesterday with no problems.

 

if you havnt solved the problem yet, ill bump it up for ya

 

hook up the VTM wire on the VAFC harness to the 31 oil pressure pin on the ECU if youhave not already done so and ensure that there is at least 300 rpm between the lo->hi, and hi->lo settings on the VTEC switchover.

if these don't fix the problem:

check your oil level.

check the TPS connector resistance at the pins and voltage across the sensor for damaged TPS or connection problems.

if you have an MSD ignition and external coil check the distributor rotor and bearings


check speed sensor and temp sensor.

 

"This past week the VTEC will not engage at first driving ( when the engine is still cold) after a little while of driving the VTEC will engage just fine."

That statement is true. VTEC will not kick in until it warms up & the right oil press. You may also want to check for a good ground on the VTEC controller.

 

Michael--
The VTEC switchover has a 300 RPM difference.
The oil level is good
I do not have MSD ignition coil adn or external coil.
Sorry, but I do not know what the TPS is.

b18vbtec-
I never had this problem before, I always let the car warm up to at least 1200 RPM idle before moving. I didn't mean I get in and just go, but what you are saying would make sense if that was the case.

I have an appointment on Tuesday, I'll see what the dealer says.

 

I've found this to be 100% true.

 

I can't imagine taking my car higher than 4000rpm part throttle until the water temp needle remains solid.....(don't have any other gauges....)

What were you doing trying to engage VTEC when the engine was cold? Ouch....
thas like jumping outta bed and running a 100m sprint without warming up!

 

I let my car warm up before I even take off. I don't just jump in and go. I don't usually try to engage right when I take off, but I check more lately since I started getting the problems with it.
I see the point of the car being cold but it doesn't make sense that the VAFC reads off for Vti and Vto.

 

lol! good analogy.

 

I don't have a VAFC, so I'm not sure what the Vti and Vto readings mean. However, I do agree with everybody else that VTEC will not engage if the car is still cold. The engine temperature needs to be high enough for VTEC to activate.

With that said, do you run into problems with VTEC after the car is warmed up?

 

The Vti and Vto and the VTEC input and output.
Can someone else with a VAFC confirm what theirs say when teh car is idle?

I told the dealer today so they will check oil pressure and so on, the rep said he will tell the tech to drive it with the computer on so they can look for any errors while driving.

 

at idle the Vti and Vto will say off......also check the settings for the VAFC make sure it has it set to a 4 cyl car and that the arrow points up and to the right. I remember once when my battery was out that the settings went back to default and those two things prevented me from engaging vtec.