Any luck with this? I am facing exactly the same problem.

 

Ok what xviper said is true, i'm sorry for starting new threads , we should keep on with this one because it's old as the problem and explains better the problem (this thread was locked before when i checked last week to post but somehow it's not now !) so i'm asking the moderator to plz take out the other ones if possible. On the other thread i last posted

now i'll biriefly explain :

-Heat soak, leading to triming retard , happens more in hotter weather, cold weather, it happens but with less power loss. More it's driven, looses more and more power.

If you read the past threads and posts you'll see what i did to eliminate problems, now i have questions about

Knock Sensor
Intake Temp. Sensor
Coolant Temp. Sensor

any ideas? might they cause something?
PS: If i disconnect the knock sensor, would the car still work and would the ecu still operate normally? i mean knock sensor is not like MAP or O2 is it? wont effect ecu right?

 

The ECU needs the knock sensor hooked up to operate the engine. Someone else here had a broken knock sensor and the engine wouldn't run too good till he put on a new one.
You can see by the temp gauge if the coolant temp sensor is working. An ECU reader should be able to see how the coolant temp sensor and IAT sensor is doing, but you already said that your mechanic hooked up your ECU and ran a full diagnostic a while ago and found nothing.

This is what I find very strange - that after having a full diagnostic, you still went and changed all those things. The diagnostics would have told you if those things needed changing and it didn't. I recall you were advised to check the fuel pressure. Instead, you just went out and changed the fuel pump anyway. Why? It's a lot easier to check the fuel pressure than it is to go change the fuel pump without knowing if it needed to be done. These are the sorts of things that have many people scratching their heads.

You say you have the best mechanic on your island and yet he didn't stop you from changing all that stuff when his diagnostics said it wasn't necessary? This is the most baffling of all.

From the start you say that you are experiencing loss of power after you drive around for a while. However, you have never described what you mean by this "loss of power". What does the car actually do? One person's "loss of power" may simply be "heat bog" and this is perfectly normal, while another is totally different. For all we know, you have changed almost every possible part on your car chasing after "heat bog". You have never told us how you drive the car. What does it do when you go WOT right up to redline when it experiences "loss of power"? How's VTEC during this time?
I believe there is a terrible transfer of information going on here and as long as this is the case, only someone who has "hands on" with your car can truly help you.

Oh, and in case a mod doesn't get around to closing it, here is the latest thread he's started:
https://www.s2ki.com/forums/index.ph...&f=22&t=313516

 

I'm not trying to jump to conclusions, but the more I read about all of this, the more I'm convinced it's just heat soak taking it's effect.

I'd try the hondata intake manifold gasket, and a cold air intake.

You also mention changing the oil every 2,000 miles. This is completely overkill. The oil doesn't even begin to work properly for that long. So it's like you're draining it just as it's starting to protect fully. Leave it in for 3,000 to 5,000 miles if using synthetic & the stock PCX filter.

 

VTEC is fine, engages, just fine. By power loss, i mean the timing gets retardted (bcoz english is my 2nd language i cant fully explain some things coz i dont know some specific names, just found out my problem is timing retard), car gets hard to drive, no performance, bogging, not responding to gas sometimes, af readings are bad, runs rich and smells rich.


Changing parts was easy because i did it under warranty. Yes, honda did diagnose the car but found only that when the freak happens the fuel pressure is low and the af readings are bad. After more tests they believe the problem occurs bcoz of a false ECU reading by some crazy sensor. They are NOT sure doe. The other mechs first thought it was a fuel problem but than after tests they changed their minds. One of the mechs said its fine after driving the car, than i found out it was the first s2k he drove. There's only 7 in my whole country which makes everything harder. I border crossed to south Cyprus to get fuel (98) and show the car to a crypton approved mech, Jp Motis. He had the car again for like 2 weeks or something, changed the injectors, swap ecu, map, o2, didnt work, he was pretty sure it's a fuel pressure problem but than he changed his mind too.

I did tell you how i drive the car before, i drive it just normal. No hard driving, no tracks or drags nothing, vtec sometimes. The problem has something to do with heat i know that. When it's hotter it gets more and more worse. IAT , like you said and Coolant Temp. Sensor , not sure, knock sensor i think is a big possibility. Plus, is there anything called Fuel Temp Sensor?

 

The fact that VTEC is quite normal for you tells me that on the most part, your car is likely running fine. Anything not quite right with the car will generally manifest itself in the performance of the car in VTEC.
How did you come to the conclusion that timing was being retarded BEFORE the instruments told you it was being retarded? This would not be the first thing that comes to most peoples' minds. That's why I aske for a more detailed description.
This car normally runs rich and can occasionally smell that way. What you describe as "hard to drive, no performance, bogging, not responding to gas sometimes", is very typical of what people experience as NORMAL heat bog and can be remedied by a CAI and getting into the habit of clearing the intake of hot air by blipping the throttle before getting going. People have learned to do this out of habbit.

Since they did all the parts exchange on warranty, I guess that was the dealer's problem for not investigating the situation better.

"I drive it just normal" really doesn't tell us much. What's "NORMAL" for you may in reality have weird elements that induces what you perceive as a problem. You may simply be driving it in such a way as to aggravate this heat bog thing.

In retrospect of all that has been posted here, I, for one, cannot come to the conclusion that there is anything truly wrong with your car. Yes, it most likely is heat related, but then, this is NOT and abnormal situation. Almost ALL S2000s at one point or another will suffer this. It has been reported since DAY 1 of this car's existence.
No, the car doesn't have a fuel temp sensor. It doesn't need one as the range of fuel temperatures that any car can encounter will not generate what you have described. The only thing that can be temperature related is a vapour lock and this would generally cause the car to stop working till the vapour lock has been eliminated.

I think it's time that you started to explore other possibilities. When this situation arises, see what happens if you blip the throttle a few times to clear the intake of hot air. It might also be time to do this mod:
https://www.s2ki.com/forums/index.php?showt...0&#entry5987875
This 50 cent solution may be the cure for what's been ailing you.

Like I said before, it would be very funny (I know it's not funny for you) if you've been chasing a "heat bog" situation all along.

 

I have posted several times on this issue, because I HAD the same issue. Everthing jacked up until VTEC. I changed the spark plugs and it corrected everything, and I havent had this issue since. It has been probably 8 or 9 months now. You may want to make sure you gaps in your plugs are correct. You mentioned you bought new ones, but did you gap them correctly? I think around 42 is correct, somebody might want to check that though, it is just from sheare memory. You should really try that and double check your plugs, sometimes you can buy them bad. Bad plugs could definetely lead to timing issues, as it did in my case.

 

When i blip the throttle for a few times than go it helps a little bit but the problem comes back one seconds later, thats for letting fresh air in and preventing heat soak right? no it doesnt help because my problem is not heat soak. The problem would sometimes show up when i'm going 120 kms and when given throttle, something like pulls the car. Spark plugs , believe me it's not the reason. I changed them 3 times, i first used new honda ones (made by ngk), didnt help, then Greddy Iridium, didint help , Greddy iridium again, didnt help. There is something wrong with the car i'm sure. Vapour lock is related to the cannister right? i swapped that with another s2k like i mentioned before.

Why i think of timing retard?
Someone posted that it might be about it and i searched about it on the net, i found that some people had exactly the same problem like i had.

When the problem is on, it doesnt go off right away, performance of the stays dead. It gets worse and worse, than it's ok again when the engine cools down, when i start the car again, after a while it starts again. Sometimes it goes away without cooling. I changed the thermostat to Mugen like i mentioned but it didnt help.

I think some sensor or part sends a wrong signal to the ecu, ecu thinks somethings wrong and pull the timing and fuel pressure, but again the question is what makes the ecu do this? No it's not a faulty ECU bcoz like i mentioned, i swapped the ecu from exactly a same model.

 

this might be a valuable learning experience to diagnose a problem...

...or it might be a complete waste of time.