2.3L VTEC performance

Hello to Everybody,

I need an opinion on the 2001 2.3L VTEC engine (which is coupled to my 2001 Accord LX 5 speed).

The car is about 8 months old and has ca 17K miles on it, but I keep having annoying problems with drivability: all of a sudden, the car would become loud and apparently loose power.
Strangely I found it helpful to just run the Code Retreival procedure (a jumper wire into the terminals 8 and 13 of the diagnostic port, then watching if the check engine light would blink- and how, etc) as described in the Haynes book.

Neither me nor the the dealership were able to see any stored codes, but strangely enough, the car begins to run well (i.e., no noise and a lot of power) after every such procedure. Then over next several days it would typically deteriorate again to its old loud ways, etc.

Maybe I am imagining things? Maybe the ECU is not ultimately concerned with quiteness and power, but rather with lowering the emissions, so it tilts the engine performance in that direction?

Please let me know if you have had any similar problem.
Many thanks in advance, Len

locate the backup wire on the ecu... it should be on the middle (blue) plug. connect a spst switch to it and leave the switch in the off position.

the backup is a power backup so the ecu stores settings while the car is off. with OBD II, the ecu reads your driving style by monitoring the O2 sensors, tps, and map. it recalibrates the fuel requirements as you cruise in closed loop then stores the settings, effectively detuning the car to keep the emissions within regulations.

cutting the backup power will clear the ecu every time you shut it off, restoring the original performance.

the only other workaround would be to convert back to OBD I, which can be significantly more expensive than a $1.50 switch.

also, if you get a check engine light, you can flip the switch to "on" while the motor is running, then shut the motor down and read the codes. once you find the problem, you just switch it back to "off" and go on your merry way.

i did this with my prelude... i worked on some performance issues on it, and afterwards, dyno'd the car. made good power. but after running it on the street for a few days and going in for another dyno afterwards for a "dyno party" me and my friends had, i found the car had detuned itself back to stock power.

highest HP reading was 174.8HP

a few days later, it was 155.3HP

Hi, thank you very much for the reply.
This sounds very valid, but I am afraid that in my case, the drop in performance goes beyond just benign detuning, it becomes ugly at times.
I will definitely try to put in the cut-off switch, though!

One other thing that I have just stumbled upon:

When I pulled out the PCV valve from the valve-cover, I noticed some amount ot oil spitting out of the hole, wiped everything off, put the PCV back in. The car seems to run good after such a procedure, but again-only for a couple of days. When the procedure repeated after a couple of days, performance seems to go back to normal, and so on.

The big question: is it normal for the engine to spit some oil through the PCV? How does PCV deal with it? Will a new PCV improve the situation?
Oil gets into the air-fuel mixture (after the throttle), then into the combustion chambers, then...fouls up the O2 sensor. Does that sound plausible?

Many thanks once again, please let me know what you think.

Len

the PCV system is functioning normally

the little amount of oil going thru the system will not harm your O2 sensor, as it's pretty much combusted as it exits the combustion chamber.

your motor probably has more oil burned from blowby than from the PCV system

Thanks again for replying,

Here is the ultimate question: what should I do to cure my Honda's intermittent bad moods? The car is still under warranty, any advise on how I should present my problem to the dealer or possibly steer them towards some productive diagnostic undertaking or repair?

Your answer will be appreciated as always.

Len

once the car starts running irregularly, take it in for service again. if they still tell you it's normal, try taking it to another Honda specialist in your area. if he can diagnose the problem, then take it back to Honda and see if that diagnosis is correct and have them do the repair under warranty.

if anything fails within this chain of events, contact the Better Business Bureau and file a claim under the Lemon Law, and tell them that your car has a problem they cannot fix. they'll be able to instruct you on further actions from there.

wait... before doing as i prescribed above, wait til the car starts running irregularly then take it to a dyno facility. see how much power is truly coming out of the motor. it could possibly be in your imagination... not saying that, but it's best to be doubly sure and have facts to back up your claims.

like you had said before, there's the big possibility that the car is just detuning itself for emissions reasons, which is reasonable as that seems to be the case with all OBD II cars.

have you bolted on any aftermarket parts that may be affecting the car in any way?

Hi,

The car is 100% stock, no add-ons.
You might be quite right on the mark about the imagination thing...

The thing is: I have had a 'traumatic experience' with my former 1996 Mazda LX V6 ( stick) which has been a terrible lemon since new, a confirmed lemon at that with multiple engine problems uncovered while still under warranty.
As a result, I keep nitpicking all the time, my idea of a hobby, I guess.

Overall, the car has been behaving OK for the past few days.
I will bother you again when I find any new leads, if I may.

I am driving to Canada (QC) for the holidays, looking forward to it.
I am taking my flock along, so we'll need to carry the skis on a roof-rack.
Can I get away with a relatively cheap piece for ca $80 (two snap-on harnesses that stay in place with spring-loaded hooks, transversely on the roof? My gut feeling is that it will get blown off at 80 MPH.

Do you have any opinion on this?

Anybody, I will appreciate you radvice on what's good in roof-racks -short of the elaborate Thule affairs.

Many thanks, Len

P.S. Drift, I looked at your website-very impressive. Where do you find such a group of car enthusiasts? How do I find such a thing in Eastern Mass, for example? Also, how do you find time?
Great job, really envy you on that.

Originally posted by Deercat
P.S. Drift, I looked at your website-very impressive. Where do you find such a group of car enthusiasts? How do I find such a thing in Eastern Mass, for example? Also, how do you find time?
Great job, really envy you on that.


my website? it's not mine... just one that i help administer. our forums were shut down due to excessive bandwidth useage, so they moved it to here.

as for a group of enthusiasts, i have just been in the business for almost 10 years now, working on import cars. i've known quite a few people in the industry who have made it big, but on my end, i decided to serve my country instead of stay with cars... but it's still a big hobby of mine.