Hi all, I know the "vtec not working" topic is very spoken about on here but i have encountered a rather weird problem.

I sent my car in to get a new ecu installed, when the tuner started the car the next morning the timing belt skipped a few teeth on the exhaust cam but no damage was done and we put a new belt and tensioner in. Eventually they got the new ecu in and the car on the dyno but now when vtec kicks in the car loses a lot of power. We manually engaged vtec at different rpms to test it but got the same result. The timing is perfect, the solenoid is clean and functioning and the car runs fine untill it hits vtec. What could this be?? It doesn't make the normal vtec noise it just sounds like the engine is struggling?

The engine in question is a boosted B16a6

Thanks in advance for any help.

 

 

My head is stock including my cams (aside from ARP head studs) and i have a normal cast iron log manifold. I have been running the system without an issue as is for about 2 years the problem only came in now.

 

 

Alright thanks for the advice I will do that. I'll just hold thumbs.

 

Are you sure?

If it "runs fine until vtec", its a tune issue.

 

I agree. This may get better results in the Engine Management & Tuning forum. I'll move it to the appropriate area.

 

look I can't say I'm 100 percent sure but i drove it home and also the tuner showed me how he engages vtec at different rpms with the ecu and it always does the same thing. But i am taking it to someone who is well respected in the honda community where i am tomorrow for him to check it out so he will check the valves and all that.

 

Thank you! That was probably a better place to post this.

 

what were the results of the compression test ?

 

Sorry for my absence. I only got the car to the honda specialist now so i will let you guys know in the next day or two what the findings are. I have a sneaky suspicion that when the tuners put the timing belt on they were turning the motor clockwise and not anti clockwise as one should on a b-series, which maybe resulted in the cam timing being out.

 

My hunch was incorrect. The timing is perfect.

 

Everything is fine. The cylinders were all with in 5% of each other.

 

my first guess is the tuner (or tune) is the problem.

Has that been confirmed or ruled out at all?

 

No that hasn't been ruled out yet but i am starting to fear that that's the case. The tuner has recently given me a few reasons to believe he is incompetent. I have booked my car for a tune at a highly acclaimed tuner who knows hondas on wednesday so we will see then i guess. I will keep you posted.

 

Hi all just an update. It turns out it was just a tune/tuner problem. Got my car back today and it is running like a dream.

 

Nice
Thanks for the update