Today I had my timing belt changed at the dealer and when I drove it home, it had much less power. It felt like the brakes were on or the car was much heavier. It also did not have very smooth power. At higher rpms the power came back but no VTEC kick. The dealer is great and I'm taking it back first thing tomorrow. Any ideas out there?
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Changed timing belt and now much less power?
- Thread starter mc-ca
- Start date
It almost sounds like the cam timing is off.
can be chock of l' do bad timing (belt badly placed), have is made the adjustment of the valves? if the valves are regulated too tightened, this it's not good! 
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Rear Exhaust Cam is retarded 1 tooth most likely, been there, done that.
To confirm, have them put a vacuum gauge on vacuum line #4 in the engine bay. At idle it should be rock steady. I would bet you will find the vacuum gauge dancing up and down. With one cam off, every other cylinder will pull differently, and it will be obvious on the gauge.
HTH,
LarryB
. To confirm, have them put a vacuum gauge on vacuum line #4 in the engine bay. At idle it should be rock steady. I would bet you will find the vacuum gauge dancing up and down. With one cam off, every other cylinder will pull differently, and it will be obvious on the gauge.
HTH,
LarryB
^ +1 Been there - done it. Be careful and don't go to high RPM's until it's corrected (it's easy to bend valves on these engines). As Larry states the idle should be smooth, but it usually isn't if the cam gears are off time.
Good Luck and Happy Motoring!
Good Luck and Happy Motoring!
Thanks for the info - I just relayed it to them. I hope it helps as they are stumped, took everything apart today to check the cam timing.
Another symptom is that the TCS light flashes when accelerating. They have been chasing that down also as a potential cause of the loss of power. Can't find anything causing the TCS activation. My guess is that the TCS system is reacting to the rough engine instead of causing it.
Another symptom is that the TCS light flashes when accelerating. They have been chasing that down also as a potential cause of the loss of power. Can't find anything causing the TCS activation. My guess is that the TCS system is reacting to the rough engine instead of causing it.
If they already took the belt off then it's too late to do a vacuum check. It would concern me deeply if they were stumped but hadn't yet checked the vacuum, and instead decided to disable the car; that is about the last thing you want to do when troubleshooting.
One other symptom: it does not seem as bad when the car is cold. I was wondering if the VTEC cam sticks in VTEC mode as soon as it warms up.
It's very unlikely and you would get a CEL if it did.
My guess is that the two are unrelated. The most common cause of the TCS light flashing is using non-stock tire sizes whose ratio of outer diameters (front vs rear) is different from stock. What year is your NSX, and what size tires are you using?
Wow, that Dealer is flirting with disaster...I am not a fan of dealers. They might see an NSX once in a blue moon. Seems like all the most experienced techs have moved on to start their own businesses.
I hope they get it all figured out.
I hope they get it all figured out.
Not necessarily; it really depends on the area. In many places, the most NSX-experienced techs are with dealers; in some others, they have their own shops. Go with the guys who have done it many times before, wherever they are working.
True, I supposed I should have said in So Cal that is usually the case. My car will probably never see a dealer while in my ownership.
All I can say is that Larry is awesome! His diagnosis was exactly right. There is a very greatful Acura Master tech in Santa Rosa. They took the belt off and started from scratch aligning everything and now it's back to it's old self. The TCS light was a symptom of the rough engine. I do have aftermarket 17/18 wheels on a '91 NSX so the TCS is a little more sensitive.
Thanks for the Help! This forum is great, especially as our cars get older.
Thanks for the Help! This forum is great, especially as our cars get older.
thx Larry for always chiming in.
I would therefore call into question the dealers ability to perform TB/WP change, mistakes can happen to anyone, but the more practice, the better you are. Just my two cents...
Yeah that scares the hell out of me. Not having that happen is exactly why I don't try to do something like this myself.
