MikeHudson

Hi guys,

I picked up my S2K about a month and a half ago now. It's 2001 and it's done 114k miles. It's been owned by enthusiasts.

A few days after picking it up I noticed it hesitate once or twice while on the move, maintaining a steady speed.

I noticed it seem to be doing it more and more as time was going by. I also began to notice the revs dipping when coming to a stop and idling. To the point that it shakes the whole car. The revs will then come back up and generally fluctuate.

I'm at the point now where it will hesitate (like it has hiccups) during most journeys. (However not ALL journeys). Once or twice it's been almost undriveable.

It's tripped the check engine light twice. A friend of mine checked the codes for me however he kept the note of the codes and I can't get hold of him to remind me what they were! So I'll have to post those up when I get hold of him. However one of the codes was intake temperature related.

It's also worth mentioning that if I run the car with the Throttle Position Sensor unplugged, it does NOT suffer the problem at all.

Having spent a while searching my symptoms and reading through threads on here, I've seen that a lot of people have had similar problems but with various fixes! So I've began trying to eliminate possibilities..

-New spark plugs (no fix)
-New coil pack in cylinder 2 (no fix) (It registered a misfire in number 2 once)
-Replaced Throttle body with throttle position sensor (no fix)
-Replaced MAP sensor (no fix)
-Removed and cleaned ICV. *Symptoms subsided for a while and became more intermittent*
-Noticed split in coolant hose, and low coolant level. Replaced hose and topped up coolant. (Instant effect on symptoms, but not permanent.)
-Bled coolant system to get rid of air (no fix)

-Compression test showed around 240 in every cylinder.
-Block test looked fine.

If anyone can offer any help or advice I'd be VERY grateful! I'm not a mechanic but I do have a basic understanding of how things work.

TO ADD - I've noticed a few people who have complained of the same symptoms also mentioning that the tone of the car sounds very 'Imprezza like'. Mine too sounds a bit like this.

TO ADD - Car has Apexi VTEC controller wired up.. running default I believe..

Update 31/03/14***

-Symptoms still present, although far more intermittent. The car will sometimes drive for hours without issue. Symptoms are just as severe when they are present though.
-Still losing a bit of coolant after replacing a split hose, could this be a problem with the coolant system somewhere? I've read air can cause these symptoms? Water pump?
-To add to the description of the fluctuating idle, I've noticed that when it decides to play up for a bit, the revs act strangely 7/10 times I pull up to a junction. If you're approaching a stop, as it slows down, the revs fall as they should and then seem to stop falling at about 1.5k despite the fact you are still slowing down. Then when you come to a complete*** stop, it suddenly drops the revs from the 1.5k where they've been holding and they plummet and bounce around too low.




TO ADD - The car still seems to be losing quite a lot of coolant even after replacing the split hose I found. Looking as if this is going to be coolant related??

Mike.

freq

Have a seat. Someone will be with you shortly.

MikeHudson

Thanks Freq, hope so! I'm really at a loss!

Shame my introduction has to be in the 'under the hood' topic! >

s2000maniac

You should get those codes and post them but maybe you should also take a look at the IAC valve. My s2k does the same thing and even turns off sometimes. I had the IAC cleaned and it helped a little but it came back. So I just bought a brand IAC and installed it today. I haven't driven the car since I'm doing some other work but I'll report back if I my s2k doesn't have those symptoms anymore. Here is how some people have cleaned the IAC but according to Billman the IAC needs to be removed and top part opened up and free the sticky valve by hand. http://www.youtube.com/watch?v=jMMUCZRQaOc

MikeHudson

Thanks s2000maniac, I'll have a go at cleaning the IAC tomorrow and see if that has any effect. I'll be interested to hear how you get on with yours.

MikeHudson

Could this have anything to do with it? >.>

https://www.s2ki.com/s2000/topic/253...-sensor-whack/

s2000maniac

^^ Yea that would be a possibility too.

MikeHudson

Here are pics of my MAP sensor. The zip tie concerns me? But if this was dodgey or causing my problems, surely they wouldn't have come on gradually like they have..

Anyone?

AZfury

I really don't like how your air filter is just there right off the throttle body, it is prob. Heat soaking allot, have you had your valves adjusted at all since your over the 100k mark?

Bliss

+2 Oh my. Get an airbox friend. Try to find a oem used one. A picture is worth 1000 words. lol

In this case 2000.

If you can call the guy you bought the car from and see if he still has the airbox. If he does go and get it. Then kick him square in the balls.