Annoying problem (please help me :-( )

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La_Pieuvre

Senior Member
Hey guys and gals,

Before I begin, here is my setup:
98 Civic EX (D16Y8) with JR Supercharger (7psi), Hondata S300, RC 440s, Walbro FP, AEM CAI, Koyo racing radiator (with new hoses), one Oxygen sensor (factory one) on header, 120k miles on car + motor, hi-flow cat + exhaust.

I've got this annoying thing happening with my car. I'll be driving and all of a sudden, the CEL comes on and the car runs rough, without letting me rev over 4k. I feels like it sputters and smells like it's dumping fuel (smell it from the exhaust). It runs shitty when that happens. There is also a whirring noise coming from the intake pipe/radiator area. It's like the engine goes into some sort of "fail-safe" mode by preventing me to rev above 4k. If I drive on it a little (as in to get off the road, and onto a residential street of something) and turn it off, it sometimes fixes it. If not, I have to wait a little while, and turn it back on to fix it.
I doesn't do it all the time, only once or twice a week. It doesn't matter whether the car is already warmed up or not. It has happened right after starting, and also after a period of driving.
Here's what I've ruled out (feel free to correct me)

1) I've replaced the MAP sensor thinking that would fix it, but it didn't.
2) I've ruled out bad gas just because, I've filled up at different gas stations with premium over the last 2 months. It also doesn't matter whether the tank is low, full or half full, etc...
3) New distributor cap and rotor. New plugs (gaped properly). New wires. New timing belt/water pump.
4) Coolant level is where it should be.
5) Check oil for milky texture, and coolant in radiator for bubbles... nothing of the sort.

I did just notice a coolant leak from the heater hoses. I am fixing it today or tomorrow, but I doubt it has anything to do with it.

Problem is, when I run the datalogging on the ECU through my laptop, the CEL doesn't appear in the software.

I'm getting really pissed off because I can't figure it out. The problem is, it doesn't happen everyday, so having somebody else look at it is hard. If it was a constant thing, I could get help.

What am I forgetting to check? I'm sure it's an issue somebody on this board has experienced before.

So, to sum up:
CEL comes on while driving.
Engine bogs/sputters and won't rev past 4k.
Dumps fuel.
Whirring noise from engine bay.
Eventually goes away for a few days.

HELP! :(

Thanks in advance for your replies, and sorry for the long post.
 
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Typical S300 glitch. Maybe try the Hondata support forum or talking to your tuner about the issue. It could possibly be a bad socketing job int he ECU.
 
Typical S300 glitch. Maybe try the Hondata support forum or talking to your tuner about the issue. It could possibly be a bad socketing job int he ECU.

Well, apparently the local Hondata dealers say that they won't touch it and that I should send it to Hondata.
I just called Hondata and they want me to bring it to a dealer to diagnose it.
I can't replicate the problem and plan on it to happen.

The likelihood that the problem will occur during the Hondata dealers' business hours and within driving distance is pretty slim.
As I can't replicate the problem, it makes it that much more fun.

So right now I'm going in circles... any other ideas?
 
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