i got the car taxed today, so was the first time ive ever driven it (http://www.fduk.org/forum/images/smilies/biggrin.gif) and you cant get the (http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif) off my face, however,
the first time i took it out boost was holding .7 bar in almost every gear (as much as i could check)
hour later i took it back out, boost was only hitting .5bar (http://www.fduk.org/forum/images/smilies/confused.gif) and im sure the more i drove it, it got worse. in 1st not even hitting boost, dropping off boost in 2nd, slow boost, it just seemed strange. and definitly not like the first drive i had.
any help or suggestions here, ive got a cat back exhaust on standard ecu too, ive heard this can cause boost spike, but from what ive read this is different symptoms to what im getting.
(http://www.fduk.org/forum/images/misc/progress.gif)
any ideas ??
Hi mate,
The same issues I have been dealing with so could do with sorting this out for each other.
I\'ve had some funny fluctuating boost problems for some time now. I\'ve been so busy that I haven\'t had chance to sort it properly.
I took a few days off work in the easter break and had all the air pipes and bits and pieces off the car ready to do a full vac hose job (got some silicone pipes from place in yorkshire) and noticed a split pipe from the vacuum chambre just in front of the UIM so replaced this and had a good look round and decided to put everything on for a test drive. The car was immeadiately much better and had much quicker response. I knew I still had to do the full job but would put it off until I had more time.
Anyway, it wen\'t funny again a couple of days ago when I was on the motorway. It seams to happen when the car has warmed up which I presume this is the same as your car? The car went into what I can only describe as limp mode where boost could be achieved (boost guage rises) but the engine wasn\'t combusting past very low revs as if either the ecu has reduced to safe mode or there is no spark. I am presume there must be fuel as it backfires in the exhaust shortly after. The whole thing is embarrasing as the car drives like a 50cc scooter with no power!
I have new spark plugs and leads had the engine re-built last year. Also, last year on the dyno, the guy told me the mixtures and ignition were ok.
So I will fix it and I have my suspicions. I will try all the bits of tests and follow the instructions in the workshop manual such as the boost sensor, double throttle control etc.
I am starting to suspect the cat has collapsed as this could explain some of the strange symptoms that are happening when the car is warmed up. It only happens when the engine warms up, the car is fine for a few miles then power is either electronically cut (ecu getting some bad feedback via broken solenoid, sensor, boost leak, exhaust probs etc) or is somehow strangled along the exhaust line.
If the cat is busted, it will get too warm and then possibly either move more inside the box or expand and deform under the added heat.
A guy I know has an RX8 and I know it is different as no turbos so no boost issues and totally different ecu. But his car had similar symptoms the other week and was limping arround so he took it to garage and the cat had colapsed which also put strain on and broke the ignition coils!
I\'ll fix it but let me know if you sort it first as you may same me some precious time!
Cheers,
Ted
I will investigate.
Quote from: Simaroon;766782i got the car taxed today, so was the first time ive ever driven it (http://www.fduk.org/forum/images/smilies/biggrin.gif) and you cant get the (http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif)(http://www.fduk.org/forum/images/smilies/biggrin.gif) off my face, however,
the first time i took it out boost was holding .7 bar in almost every gear (as much as i could check)
hour later i took it back out, boost was only hitting .5bar (http://www.fduk.org/forum/images/smilies/confused.gif) and im sure the more i drove it, it got worse. in 1st not even hitting boost, dropping off boost in 2nd, slow boost, it just seemed strange. and definitly not like the first drive i had.
any help or suggestions here, ive got a cat back exhaust on standard ecu too, ive heard this can cause boost spike, but from what ive read this is different symptoms to what im getting.
(http://www.fduk.org/forum/images/misc/progress.gif)
thanks for your reply mate,
sounds a very similar problem to mine,
i dont think i have any split pipes because sometimes the boost is perfect, other times it doesnt boost. surely with a split hose it would never have full boost.
the more i have used the car now, the more i have seen the problem tho.
i find when in 3rd gear it is at its worst, over boosts to .9 bar then dips to about .5 then back to .7, then when the 2nd turbo comes in theres a quick loss of boost and back to .7 bar. the gauge really is all over the place in 3rd.
when put into 4th tho, immediatly to .7/8bar and holds it there through the rev range perfectly.
then yesterday after driving for about 15miles and being on dual carraige ways and hitting boost, come off a roundabout in 2nd, WOT and no boost at all, absolutely nothing :confused: so i lay off the throttle and go throught the gears, get to fourth and boost is back and perfect again, very strange.
im really at a loss with it, ive never thought of it being the cat tho, off to do some digging for more info on that.
I really don\'t have much experience with the car other than driving it. The cat thing is something that I thought it could be given that it happens when the engine is warm and it is an easy thing to check and eliminate!
Many people who I have spoken to who are mechanics on these cars always suggest testing the solenoids under the UIM. My car can\'t even reach boost in the 2nd turbo at the moment so this is why I am going to check the cat.
The kind of boost patterns you are getting are similar but I think mine are worse! If I had the boost you are getting, I\'d quickly check the cat and also check the solenoids.
Just to update you, Changed all the rats nest pipework. I had the car to WGT who sorted everything out. Had a broken air temperature sensor reading air temp below 200 degrees C so was throwing too much fuel in on low rpm plus other issues, solenoids etc and a collapsed CAT which was replaced with cheap hi-flow model. All sorted with good bhp and torque figures. Now it\'s boost creaping due to the hi-flow cat so may have to adjust the restrictor pills or exhaust to sort it out. Back to WGT at some stage.
Get the wastegates on the turbo ported so it doesn\'t boost creap then.
I thought the replacement restrictors that were inserted could be too small especially with the hi-flow CAT and free flow muffler.
I\'ve had a look at porting the wastegate and I know it\'s the answer but it looks a right ball ache!...
Quote from: m1tch;815829Get the wastegates on the turbo ported so it doesn\'t boost creap then.
Quote from: Tedrux;816061I thought the replacement restrictors that were inserted could be too small especially with the hi-flow CAT and free flow muffler.
I\'ve had a look at porting the wastegate and I know it\'s the answer but it looks a right ball ache!...
But overboosting and needing and engine rebuild isn\'t?
I understand about the wastegate but I\'m looking for a quick solution such as exhaust restrictor or restrictor pill / manual adjust as I\'m happy with the stock power levels for the moment. I am going to tackle it this Satdy. If it doesn\'t work, then I\'ll have to look into more involved procedures as you suggest.
I will eventually be looking for some performance mods this year but not without understanding of what I need for my driving habits.
Quote from: Simaroon;768406thanks for your reply mate,
sounds a very similar problem to mine,
i dont think i have any split pipes because sometimes the boost is perfect, other times it doesnt boost. surely with a split hose it would never have full boost.
the more i have used the car now, the more i have seen the problem tho.
i find when in 3rd gear it is at its worst, over boosts to .9 bar then dips to about .5 then back to .7, then when the 2nd turbo comes in theres a quick loss of boost and back to .7 bar. the gauge really is all over the place in 3rd.
when put into 4th tho, immediatly to .7/8bar and holds it there through the rev range perfectly.
then yesterday after driving for about 15miles and being on dual carraige ways and hitting boost, come off a roundabout in 2nd, WOT and no boost at all, absolutely nothing :confused: so i lay off the throttle and go throught the gears, get to fourth and boost is back and perfect again, very strange.
im really at a loss with it, ive never thought of it being the cat tho, off to do some digging for more info on that.
Your getting boost creep mate, if you are on a stock ecu then it retards timing to prevent knock. If the issues get with low boost get worse as the car gets warm then usually one of the solenoids is sticking.
Either test them indivIdually or get a pfc and a map for happy days