Gotta vtec problem on a customer car.

1998 accord manual tranny f23 SOHC vtec.

I have just installed a full catback, OBX high flow cat, headers, and intake.

I'm behind the wheel taking a test drive with the customer in the passenger seat and the dude is THRILLED... Talking about how much faster it is, how great it sounds, etc. I'm sitting there thinking THIS THING IS A TURD.

No pop, no rush, no appearence of increased power leading me to believe that VTEC isn't engaging. He said that he's never been able to feel it. Granted, I'm used to working on/driving twin cam motors, but I know that the system is very similar on both types and assume that VTEC isn't working properly.

Thing is in 5 years of honda work I have never run into this one yet. Maybe I'm just lucky, but what would you say as far as probable cause? VTEC Solenoid? ECU? Clogged/restricted oil line? Or is the VTEC on the F23 just so weak that you can't even notice it? (hopefully not likely)

I just want to get this sorted out before we move on to begin forced induction on this thing in 2 weeks.

 

check if you plugged in the connector for the vtec solenoid.. or the wires to it. Hopefully you didnt damage the solenoid itself when the intake was installed (could be possible). In my case (96 accord) on an f22 is resides right under the intake tubing (found this out trying to rig a 97 prelude intake tube onto the car. its not very noticable as in put you back in your seat type of difference, but you can definitely notice a change in the sound of the car. should occur at around 3800 rpm.

 

F23 has variable vtec - it engages when the computer "thinks" it should. You won't feel it like a B series, since it's only an SOHC (vtec on intake side only) and it engages at different points. Sounds normal to me.

 

Agreed. You probably just don't notice it. What do you think this is? A B18?

 

Maybe the long *** gears are fooling you.

Even with those mods, you should be able to hear it.

Tell you what. Hop on the highway, and cruise at 70 MPH for a bit. Go WOT, and you should hear a whining sound. It doesn't sound like anything special, but it is there.

If that doesn't produce a positive result, check the oil level. The lack of oil will stop VTEC from engaging.

 

F23 is SOHC, and SOHC VTEC only has the VTEC Rocker mechanisms on the intake side. on the cam, the two exhaust lobes are on either side of the 3 intake lobes. there's no way to fit two more lobes near the exhaust without it ending up outside of its intended cylinder. with only the intake bring on VTEC, it maybe gives as much power as a DOHC non-VTEC of similar size (H23). You're not going to get a pop, a rush, or anything out of SOHC VTEC. it's apparent you've worked with mainly DOHC because the harmonics change when both the intake and exhaust lift/timing is changed.

SOHC VTEC:

 

unplug the vtec solenoid, u'll feel what a non-vtec feels like.

 

/\ where is the vtec solenoid?

 

on the back of the head, passenger's side

 

I'm definately used to working with b/h/k series motors, so the SOHC VTEC feeling (if it exists) is completely alien to me. Might be that the system is working fine and I just don't notice it.

 

its normal. you cannot feel vtec in these f motors unless its like a f20c.

its nothing like b's and h's and k's. accords are slow as *****. i know ive had one my whole life.

cant here it or feel it but it is working, youll get a CEL if it wasnt. for pressure switch or solenoid, even vss, temps... all that

 

Well thanks guys, that must be it. Vtec is working great, but I'm just a dummy. Thanks for the help everyone. Thread's done.