2003 JDM boost problem
22 June 2013, 01:26 PM
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2003 JDM boost problem
Hi guys,
My 2003 sti JDM has developed a boost problem......
I was going onto the motorway and got the car up to about 4.5k rpm, under full chat. Car was boosting perfectly and then I felt it loose boost?
The car runs, drives and idles fine and there are no warning lights on the dash. I have checked all boost hoses and all other hoses, no leaks were found and everything was tightened. This made no difference. I changed the DV back to the standard item (from an HKS), still no difference. I've just cleaned the air filter and am waiting for it to dry (the filter was pretty minging).
The car is perfect, except not boosting properly (I would say it has lost about 70 - 80% boost, there is still a very small amount of boost, as if something is restricting it??)
Car has been mapped and has a full miltek with sports cat but has been running perfectly up until the point where it lost boost.
Any ideas guys?
My 2003 sti JDM has developed a boost problem......
I was going onto the motorway and got the car up to about 4.5k rpm, under full chat. Car was boosting perfectly and then I felt it loose boost?
The car runs, drives and idles fine and there are no warning lights on the dash. I have checked all boost hoses and all other hoses, no leaks were found and everything was tightened. This made no difference. I changed the DV back to the standard item (from an HKS), still no difference. I've just cleaned the air filter and am waiting for it to dry (the filter was pretty minging).
The car is perfect, except not boosting properly (I would say it has lost about 70 - 80% boost, there is still a very small amount of boost, as if something is restricting it??)
Car has been mapped and has a full miltek with sports cat but has been running perfectly up until the point where it lost boost.
Any ideas guys?
Last edited by Peedee; 22 June 2013 at 01:29 PM.
22 June 2013, 01:46 PM
#2
are you sure its not the hot ambient temperatures, having had turbocharged petrol cars for some years now I noticed the hot weather seems to effect it quite a lot, especially as you have a top mount the heat soak can effect the boost.
Last edited by tubbytommy; 22 June 2013 at 01:48 PM.
22 June 2013, 01:52 PM
#3
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No, in short. I see what you're saying, but there's no way that the car could lose so much power just through a bit of heat soak. I felt the car physically lose power in one swift go coming onto the motorway, and since then it hasn't been boosting properly.
22 June 2013, 02:46 PM
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Had a similar problem, actually it was 2 problems, one was the camshaft sensor the other was the NPS.
Best bet is getting it on a diagnostic machine/rolling road to see what it pulls up.
Tony
Best bet is getting it on a diagnostic machine/rolling road to see what it pulls up.
Tony
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22 June 2013, 03:14 PM
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The engine management light is not on mate. No other lights on the dash either (except the ones that shoud be on!). Everything looks normal.
22 June 2013, 06:29 PM
#12
If the boost just fell away it sounds like a pipe is off or split or maybe your actuator has come off the waste gate arm there's a load off vacume hosese are you sure you've checked them all
22 June 2013, 06:34 PM
#13
22 June 2013, 06:43 PM
#14
My nps played up when I had the l/c mapped I suppose if the car thinks its in neutral then it could take the boost out the equation but I'm guessing I don't know if the nps could do that didn't scooby clinc have a issue with a nps switch that troubled them cant remember what it was now.
23 June 2013, 11:41 AM
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It might not be on but does it actually work? When I bought mine it had a running and boost issue but no engine management light was on. When I started investigating it the engine management light didn't actually work.
23 June 2013, 12:12 PM
#22
It will have two vac pipes attached to it one going to the inlet trunk and one leading to the turbo/actuator on a T piece. Remove from drivers side strut tower remove vac pipes and clean with some brake cleaner.
24 June 2013, 03:03 PM
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No idea if this will be anything to do with your problem, but i found my lack of boost was due to the exaust been lose on the front section where it leaves the manifold
28 June 2013, 01:00 PM
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Hi guys,
Ok, update for any one else who may have a 'mapped' JDM (no doubt applies to uk cars too!)
Firstly, thanks to Paul @ Xtreme Scoobies for sorting it!!
Ok, so, plugged the car into the diagnostics, took the map off and drove it up the road.....perfect drive with the standard map and, more importantly, boosted fine (although the overall power of the car was obviously down, but this is to be expected with the standard map).
The Powerstation map was then put back onto the car, test drove and was fine. It's suspected that the MAF may possibly be on the way out, but for now, its fine. When the MAF goes, it goes, no great drama, but until then, its back to normal!
Ok, update for any one else who may have a 'mapped' JDM (no doubt applies to uk cars too!)
Firstly, thanks to Paul @ Xtreme Scoobies for sorting it!!
Ok, so, plugged the car into the diagnostics, took the map off and drove it up the road.....perfect drive with the standard map and, more importantly, boosted fine (although the overall power of the car was obviously down, but this is to be expected with the standard map).
The Powerstation map was then put back onto the car, test drove and was fine. It's suspected that the MAF may possibly be on the way out, but for now, its fine. When the MAF goes, it goes, no great drama, but until then, its back to normal!
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