Toyspeed.org.nz Message Board

by **loudstealthGT-Four** » Fri Aug 07, 2009 10:08 pm

New problem of the week.....

Last couple of days my boost would sometimes go up to 14psi and hit fuel cut done this to me this morning and then now...

When i am accelerating and boost gets to about 6-7psi my car starts stuttering and I get a fluttering noise out of my exhaust and then if I keep my foot down the whole car starts vibrating/shaking

by **jakesae101** » Fri Aug 07, 2009 10:17 pm

vacume leak? running a boost tap? sounds a bit like free boosting

by **loudstealthGT-Four** » Fri Aug 07, 2009 10:25 pm

No known leaks. No boost tap. Can ya explain free boosting thanks

by **jakesae101** » Fri Aug 07, 2009 10:37 pm

loudstealthGT-Four wrote:No known leaks. No boost tap. Can ya explain free boosting thanks

my understanding of it is that there can be a leak in one of the vacume lines causing uncontrolled boost pressure

by **FLAWLES** » Fri Aug 07, 2009 10:40 pm

do they run a factory type bov?
if there anything like the 1jz ones after a while they tend to pop apart and leak boost pressure

or so i have read

by **loudstealthGT-Four** » Fri Aug 07, 2009 11:04 pm

Yea has a factory bov/bypass valve I'll try look at all the vacume hoses tommorow. Bov still works fine.

by **TRD_ZERO** » Fri Aug 07, 2009 11:07 pm

Im not too familiar with the gtfours but do they run airflow meter? If so then sounds like a boost leak like mentioned earlier. I had that when the airflow meter reads a certain amount of air comming in but leaks out somewhere.

by **iOnic** » Sat Aug 08, 2009 10:05 am

Probably went into limp mode after hitting boost cut (ecu safety feature). Does it drive fine after turning the car off and starting it up again?

by **loudstealthGT-Four** » Sat Aug 08, 2009 10:16 am

It's not limp mode. When its in limp mode it will cut out as soon as there's any boost. And it still does it when I reset the ecu

by **iOnic** » Sat Aug 08, 2009 10:20 am

Hmm might be a boost leak after the AFM or a dodgy T-VSV. Could also be a warped exhaust manifold. Mine used to shudder/hesitate at around that boost level when it had a warped manifold and would sound like it was backfiring out of the exhaust

by **fivebob** » Sat Aug 08, 2009 10:50 am

Maybe time for new Leads, Cap, Rotor, & Spark Plugs.

by **loudstealthGT-Four** » Sat Aug 08, 2009 1:08 pm

Ok had a look this morning can find any leaks (just a rough look). Put my old top mount intercooler back on and problem wasn't as bad but still there, boost got up to 14psi again and hit fuel cut. Put my front mount back on and problem was not as bad same as top mount. The noise coming out the exhaust is a backfiring noise. Boost now gets up to 10+psi

thanks for all the suggestions

by **flygt4** » Sat Aug 08, 2009 4:34 pm

fivebob wrote:Maybe time for new Leads, Cap, Rotor, & Spark Plugs.

definately do this first.

also look for leaks around turbo intake elbow, especially cracks in the corrugations. also on the off chance , check the turbochargers wastegate actuator arm isnt sticking, and that all the factory VSV hose are connected correctly, or bypassed properly.

ST185's have no factory bypass/BOV so i'm not too sure what you're referring to there. the compressed air goes directly from the turbo, about 1.5 inches into the factory top mount, then about 1 inch into the intake.

If an ST185 hits the fuel cut, it won't allow you to boost at all and will repeatedly cut above a couple of psi until you restart the engine. I know this because my old one would occasionally hit it on cold nights, and i quickly mastered turning the car off and crash starting it (until i got a FCD) :wink:

by **loudstealthGT-Four** » Sat Aug 08, 2009 5:16 pm

Where is the VSV? and also can someone explain to me why i need to change Leads, Cap, Rotor, and plugs?

Thanks

by **loudstealthGT-Four** » Sat Aug 08, 2009 5:19 pm

[quote="flygt4"][ST185's have no factory bypass/BOV so i'm not too sure what you're referring to there. the compressed air goes directly from the turbo, about 1.5 inches into the factory top mount, then about 1 inch into the intake.
quote]

Then what is making the "chish" sound when i let off the accelerator?
I dont have a aftermarket bov on my car.

by **sprsta** » Sat Aug 08, 2009 5:35 pm

that will be compressor surge usually sounds like sequential (fluttering) bov i usually get that if i dont produce enough boost (or none at all) for the bov to open you will notice it alot more with a pod filter or the like

by **iOnic** » Sat Aug 08, 2009 5:36 pm

Air coming back out of the turbo. I assume you have a pod filter? That would cause the sound when you take your foot off the gas. It's not "compressor surge" as it's commonly called, that's a different thing altogether.

The hesitation could be a misfire due to worn out leads/cap/rotor/plugs (or all of the above). They are all periodic maintenance items so if you've never replaced them they're probably well past their use by date.

by **loudstealthGT-Four** » Sat Aug 08, 2009 5:57 pm

oh ok thanks. Ive only had the car since april. Ill take it in and get it checked out

by **MAGN1T** » Sat Aug 08, 2009 7:57 pm

Don't those top mount intercoolers have dodgy connections to them?

Steve

by **loudstealthGT-Four** » Sat Aug 08, 2009 11:25 pm

MAGN1T wrote:Don't those top mount intercoolers have dodgy connections to them?

Steve

didn't have any issues with mine when it was on

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