In the MDX (J35) there is a very obvious increase in power around 4100 rpm. There is also a very noticeable difference in the sound and the rate of increase in rpm past that point. I believe thats where the VTEC is kicking in.

But in the Accord(F23) I dont experience anything that's as noticeable or obvious.
So I want to verify that VTEC is indeed kicking in. How do I do that ?
Ultimately the VTEC solenoid should engage, right ? How do I check that it is indeed engaging ?

I have heard the hot-wire method to test the solenoid. I haven't dont that yet, but even if it passes that test, it doesn't mean vtec is kicking in, right ? I want to check when the car is moving that vtec is indeed working.

Thanks!

 

FYI the F23 is not known for it's killer VTEC. It's more of a fuel saver VTEC than a power adder.

If you want to know you could add an LED light. grab a length of wire and attache the LED Positive to the (+) pin/wire on the VTEC solenoid and ground the other wire to the chassis. Run the wire so it's just sticking out from under the back of your hood close to the windshield and you'll see when the solenoid is actuating. If you want a more permanent fixture you could tap into the ECU wire (C10 on the OBD2b I believe. Someone please correct if I'm wrong) side of things and have it run in your dash somewhere.


Modified by GhostAccord at 2:20 PM 4/1/2008

 

I would guess if vtec wasnt working you would have the CEL on.... is your CEL on?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dwayne1413 &raquo;</TD></TR><TR><TD CLASS="quote">I would guess if vtec wasnt working you would have the CEL on.... is your CEL on?</TD></TR></TABLE>

not true. there are several variables in which vtec won't work and the cel does not come on. for example. mine.

 

ok I think the VTEC is working (and in the process I think I also might have found out when exactly it kicks in).

After connecting a wire from battery +ve to the solenoid and verifying that the solenoid is working, I left the solenoid disconnected, yes on purpose . And drove around without it.
As for the CEL, nope no CEL even yet. BUT, as soon as I stepped on it enough to rev it past 4k rpm, the motor cut in and out and the CEL came on.

So I guess I can safely assume that the VTEC is working, and kicks in at 4k rpm ?
What you experts think, fair enough ?

 

i doubt very seriously if vtec kicks in at 4k unless you have modified via ecu, chip or vtec controller. stock is like 5000-5200k when vtec hits. i know jdm is 5200 i am not sure about usdm.

 

i was havin the same crap problem with the vtec (f23a1) and got it fixed n the reason was my stupid temp guage!!!! it was grounding and screwin it up! but now i have a whole different issue tho and that is after driving when i slow down or stop the car, it starts revving on its own? =/
at 8-900rpms, the rpm starts freakin out and the check engine light came on too! (
is it normal for the car's rpm to be freakin out like this after getting a ported head, intake manifold and a mild cam?? could it be the cam gear?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flight50 &raquo;</TD></TR><TR><TD CLASS="quote">i doubt very seriously if vtec kicks in at 4k unless you have modified via ecu, chip or vtec controller. stock is like 5000-5200k when vtec hits. i know jdm is 5200 i am not sure about usdm.</TD></TR></TABLE>

nope its stock ecu. although I would be surprised if really vtec kicks in that late for a motor that redlines ~6k.
hopefully will get some time to try out the parallel LED idea by this weekend. that should tell the real deal.

 

VTEC can be engaged at any RPM over 2300 - 3k depending on these 4 conditions RPM, VSS, ECT & MAP

1. Engine Speed, RPM: 2300 - 3200 rpm (depending on manifold pressure)
2. Vehicle Speed, VSS: 6.2 mph or faster
3. Engine Coolant Temperature, ECT: 50°F (10°C) or higher
4. Load: Judged by intake manifold negative pressure MAP.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flight50 &raquo;</TD></TR><TR><TD CLASS="quote">i doubt very seriously if vtec kicks in at 4k unless you have modified via ecu, chip or vtec controller. stock is like 5000-5200k when vtec hits. i know jdm is 5200 i am not sure about usdm.</TD></TR></TABLE>

I've never heard of it kicking at 5k rpms in an F23. I've heard anywhere in the 3-3500 range.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GhostAccord &raquo;</TD></TR><TR><TD CLASS="quote">

If you want to know you could add an LED light. grab a length of wire and attache the LED Positive to the (+) pin/wire on the VTEC solenoid and ground the other wire to the chassis. Run the wire so it's just sticking out from under the back of your hood close to the windshield and you'll see when the solenoid is actuating. If you want a more permanent fixture you could tap into the ECU wire (C10 on the OBD2b I believe. Someone please correct if I'm wrong) side of things and have it run in your dash somewhere.

Modified by GhostAccord at 2:20 PM 4/1/2008</TD></TR></TABLE>


I really wanna do this. I would like to know some things first. What kind of wire would I need? Where is the vtec solenoid located, and how would i attach the wire? Or how would I tap it into the ECU C10?

Is there any write up on this?

 

The vtec solenoid is located on the left-back hand side of the valve cover.

Search vtec LED and you might find some stuff from the EG/EK forum

 

same deal with the F22, i cant really tell mine either. HUGH diff going from my moms 06 Si and then to mine lol the F22 and F23 are not performance engines. vtec will not kick in nothing like a B, H, K, or J will. One way you can kind of feel it is to drive in 3rd gear from low speed and take it all the way to redline with slow accel. thats how i was able to feel mine. I only gave it about half throttle maybe. it still wasnt not big kick in of vtec but i could tell it was there

 

In ALL of my F23's, VTEC engages at ~2300rpm for normal driving. Basically, if you punch the throttle above 2300rpm, VTEC will engage.

Easy way to see... Unplug the the VTEC solenoid and drive around for a while. The stock ECU isn't mapped to rev over 4K on the standard cam lobes, so you'll hit a sort of 'rev limiter'. You'll quickly see how much it sucks not to have it.

Some idiots use a piggyback controller to set VTEC engagement around 4Krpm, and claim 'oh you can really feel VTEC kick in at 4K, and it's a 25hp jump!' Well congrats, you just jumped from ~100tq to ~140tq, where you should have been climbing to that whole time!

The reason they say that is because by their torque curve on the standard lobes drops drastically beyond 3K, and when the VTEC lobes engage, they're only jumping up to the normal power curve the motor was intended to produce. Basically robbing themselves of power from 2K-4Krpm.

I know many will try to bash me for this, but VTEC in an F23 was actually designed to produce more power, but not in the sense of performance top-end that most assume is it's only purpose. The standard cam lobes are your 'fuel efficient' lobes. They provide low power and high efficiency at low rpms for light city driving and highway cruising. So no, F22/F23 VTEC wasn't designed to blast past 5-6Krpm, but it does provide a substantial torque increase at the lower (2-6K) rpms where our engines operate.

Hope this clears some things up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by josh’s_accord &raquo;</TD></TR><TR><TD CLASS="quote">same deal with the F22, i cant really tell mine either. HUGH diff going from my moms 06 Si and then to mine lol the F22 and F23 are not performance engines. vtec will not kick in nothing like a B, H, K, or J will. One way you can kind of feel it is to drive in 3rd gear from low speed and take it all the way to redline with slow accel. thats how i was able to feel mine. I only gave it about half throttle maybe. it still wasnt not big kick in of vtec but i could tell it was there</TD></TR></TABLE>

Easiest thing is to listen, and since only the intake lobes are affected, the intake is where you'll hear it. An aftermarket (unbaffled compared to stock) intake makes this 100x more audible. Start in second or third like you said, at a low rpm, and just peg it. You MIGHT feel it a tiny bit, but you're more likely to just hear the valves open up.

 

dang. my bad. i didn't pay attention to what type of motor you had. i was speaking on the behalf of the h22 with is a total different animal.

 

ok I hooked up the led and in regular city driving it engages at ~2500 rpm.
In highway/cruise driving it engages ~3100 rpm.

Although you can't really say in general that it kicks in at x rpm because it depends on the engine load (i.e. manifold pressure) also. You could be cruising along at 2700 rpm and yet vtec would not be engaged. But as soon as you apply a little bit throttle then vtec engages. Thats why I generalized that factor as "city driving" and "hwy driving" and seperated them out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AnAccordIsForever &raquo;</TD></TR><TR><TD CLASS="quote">ok I hooked up the led and in regular city driving it engages at ~2500 rpm.
In highway/cruise driving it engages ~3100 rpm.

Although you can't really say in general that it kicks in at x rpm because it depends on the engine load (i.e. manifold pressure) also. You could be cruising along at 2700 rpm and yet vtec would not be engaged. But as soon as you apply a little bit throttle then vtec engages. Thats why I generalized that factor as "city driving" and "hwy driving" and seperated them out.
</TD></TR></TABLE>

Ah... another individual enlightened.

 

NOOB TOO HONDAS BUT WAS IS THE SOLINOID?

 

No need to use all caps.

The solenoid is what engages the vtec. It's located on the left-back side of the valve cover.

I'd like to test out your signature.

 

x2 @ sig

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HONDAD15B1 &raquo;</TD></TR><TR><TD CLASS="quote">
I smoke a v-8 like smoke maryhanna</TD></TR></TABLE>

Running a D15b1...... So your saying that you don't smoke maryhanna at all then!

 

aahh theres nothing like smoking a v8 with a little I4...then again a hit after a 10hr day at work is nice too

 

I still remember the license tag on the last four cylinder that handed me my ***.

"2L8V8"

Of course it was the ONLY four cylinder that has EVER beaten me, (of course it was a 4 cylinder with $20,000 in the engine ALONE so it was kind of a no-brainer who would win that one).