merkis1024

Hello S2ki,

I've been tracking my S2000 for some time now. I started to notice something weird on my car since a couple track days ago.
I typically don't have a problem until maybe 3rd or 4th session in.

My engine feels like it's lost some power and won't accelerate as fast as it did in the morning. I'd say the loss of power is significant enough that it's not just hotter air.
Then, after a hard left turn (specifically after sunset at Buttonwillow), engine just ... doesn't accelerate at all.
RPM climbs very slowly.

At first, I thought maybe it's fuel starvation due to g force. To eliminate this as possible cause, I fueled after lunch, so I'm pretty sure I had sufficient fuel.

This happened quite a few times. Last time this happened, I looked at the water temp gauge and it was quite higher than normal. (115C according to stock gauge) I can't say coolant was overheating during other times too, but I did notice it was at least once

Do you think it's related to engine overheating? Can it lose power when engine is overheating?
My current suspicions are:

1. overheating?
2. fuel pump malfunction
3. misfiring? Although I think this would throw some CEL's.
4. clutch issue? I doubt this one because if clutch is slipping, rpm would climb but not mph.

thepoi

My 07 did something similar a while back. No earthly idea what happened. The exhaust even sounded weird. All temperatures were fine, no codes. I wasn't datalogging with my flashpro, but that may have pointed to the issue. I had assumed the cat in my Berk system had melted down--the insulation had detached and could've have block about 10-15% of the open area, but that didn't really convince me. I removed the cat for the next track day, and had no issues whatsoever even with higher ambient temperatures.

pgss2k

Map sensor? I had to put a tie wrap around mine to keep it tight. I'm AP1 though

ViperASR

115C is about 240F which is really, really hot for coolant. I'd bet oil temps were well well above 300F at that point as well.
I'd figure that is some of the issue, if not all of it, especially since its happening in the afternoon sessions.

Another idea is that it could be oil being sucked into the intake as you get faster, causing a loss of power.

miamirice

I went through this on a k20. Would really show itself progressively as the motor warmed up. It was a crack in the intake manifold

merkis1024

Hmm. Although I also have a hard time concluding that my cat melted, I will keep that in mind as my next option! Test Pipe is a cheap mod that will eventually come anyway. Thanks!!


MAP sensor is the one right after the throttle body right? you just tightened it down around the TB?


I know, i've never seen my coolant temp go that high on my gauge before. Especially because I have a Koyorad radiator. I'm installing an external gauge to read water and oil temps soon. Could you explain your second theory? Are you referring to the engine oil? (the ones that get routed into the intake arm)


Ah.. I really hope it's not a cracked intake manifold.. Although even if it was, I already bought a bored-out intake manifold to install, so I won't have to spend more money..



THanks everyone for the inputs!

davidc1

Couple things I'm thinking of...

You said you added fuel, but didn't say how much. It seems to vary for different S2k's, but you should try to keep a half tank. I've heard of cars starving at 1/4 tanks, and others fine.

Second thing I'm thinking is oil starvation. You will run very hot, and loose power. Unfortunately, to know for sure there you have to install an oil pressure gauge and keep an eye on it.

pgss2k

MAP sensor is 2 part clip connection. Wrap the tie wrap around the 2 parts to keep them tight.

SmokeyGatto

i'm thinking map whack. had a similar issue, now fixed.

feels like a misfire, but its more of a hesitation.

APoner

I hit fuel cut sometimes when im under half a tank but im also running a bigger pump.