00W P1
FULL DECAT
HKS SSQV

HESITATION ON LIGHT THROTTLE WHEN ENGINE COLD,
FINE WHEN WARM.


ANY IDEAS?

 

Let it warm up a bit, then drive it.

 

Not sure what's causin' it but do know it's quite a common problem ... hopefully nothing to worry about, just a characteristic of the engine when cold.

 

CHEERS BRAD.

 

TOP

 

Hi matey

My P1 doesnt drive so well when its cold either, just a charactersitic of the engine I think. Make sure you warm it up fully before you drive hard and as long as there is no hesitation then, its fine! If there is any sort of erratic idling or hesitation when its warm then it could be the usual MAF fault on these cars!

Stu

 

i do warn it up correctly, and once shes warm, it pulls smoothly like a train.

mayb just the way she is.

regards

 

It runs on a closed cycle until it's warmed up - to do with hitting emission targets - so it will feel lumpy - nothing wrong. Once warm it goes to open cycle i.e. the ecu will add or subtract fuel depending on the air flow it sees up to the pre set limits.

However, by decatting a P1 ( or the equivalent JDM STi) you are risking it as the extra air that will flow will result in a leaner charge which takes two specific areas of the map to very lean.

With the cat in place these areas (around 4800 rpm is a noticeable one) are covered adequately by the ecu running comparatively rich, however the extra flow as a result of the unrestricted exhaust will take the air volume beyond where the P1/ StiV ecu can compensate for.

So for safety run with lots of Octane booster or get a remap. My p1 has an ecutek3 by Bob Rawle and, apart from releasing some more power and smoothing out all the lumpy bits post decat, it is more importantly, to me anyway, safe with a decat.

 

That is the clearest, most authoritative explanation of what happens in a scoob's engine that I have ever read in here, and goes some way towards explaining why so many P1s get blown up by their owners.

Apologies to anyone else who may have posted something equally as good in the past.

 

cheers fat boy!!

goood reply.

 

P1's need re-mapping with a de-cat pipe simple, also the MAF sensor may cause this.

Mate had a P1, brought a full Blitz exhaust, air filter and blow off valve, was told the car will run fine by a well known tuner, i won't say who.
Within 2k it had melted two pistons.
His old man rang the local dealership to enquire why a car with only 20k on the clock would do this. The man from the dealer told him which two of the pistons had melted, my friends dad confirmed he was right, he then asked had he put an exhaust with a de-cat, again my friends dad confimed. Then the gentleman informed him P1's ECU's are conformed to uk standards, unlike us imports, and there for when ever the fueling/air are played with they quite simply get the hump, run lean and melt pistons.

Only telling what i know.

 

Fatboy,
Sorry I'm not the brightest button in the box

During warm up "Closed loop cycle" what part does the LAMBDA sensor play? or is the LAMBDA only used in open loop cycle?

and if used during "Closed loop cycle" could a faulty unit cause incorrect fueling/hestitation etc like he was experiencing?


Tony

 

The infamous Tony,
I saw a video yesterday of your off in your Bugeye, i've only been on here a few months so wasn't aware it was an old video and that you were a member of Scoobynet, just wanted to take this moment to say i didn't put it on as a hahaha look at this.

All the best Swen6

 

Sorry Phil a bit off topic.

LOL I also met some peeps at Powerstation last week, and the said " So your T5NYW"

Yep That was me at JAPFEST 2004, Castle Coombe and I haven't a problem with it being mentioned it is a shame the 4 other laps get as much airing as the Crash one.

The original thread and my "Excuses" are HERE


Tony

 

I agree with above posts. The p1 one feels unhappy until its warm, not that I would ever give it stick until then.

A remap after warranty might be the way forward. Not before though IMO

 

Now don't castigate me for this boys but the p1 ecu is a little unfinished. it is said that the car will run on 95 octane fuel but this is not the case so some do blow up. The p1 comes from the factory with broquet fuel pellets which should theoretically last the life of the car and allow safe running with 95 octane fuel they don't on both fronts ie last the life and allow safe running. the first thing you should do is get a re map more for reliability than performance. Would i be right in thinking the ecu is the same as a sti v type r? Albeit slightly altered for uk.

 

The p1 ecu was altered to allow for a bit of knock correction. If you tried running it on 95 ron, it would probally work. Wouldn't expect it to last long though. Remember the Japs have 100 ron. Any un-remapped import will suffer harder than the P1.

Not sure about the fuel pelet theroy, Prodrive/Subaru did cut a bit of a corner with the map, but would they RELY on that??

 

yes mate as far as i know that is what happened. Remember the p1 project did not run smoothly at all.