Help!! car jerks at 6k rpm

[Newt]

Hello rotary gurus and sifus,

Need your opinion on this problem i have on my rx7 FC. The car cannot maintain its boost pressure, once it hit its cap (0.8) the boost needle slowly dwindles down, and when i shift into 4th gear, with near certainty, everytime the rpm hits 6k, the turbo looses a lot of boost, the needle dramatically drops, and the car jerks... :-(

But just momentarily, once it passes the 6k mark, it goes on as usual (but of course, boost keeps on losing pressure...)

Sometimes when it's idling, the boost goes down really far (when it's normal, usually at around 300 below 0 bar, but when something's wrong, it goes down to 500 :-p i don't know what that means, and i'm just reading out the numbers on the boost meter.. i hope i'm making sense here :-p) and when i lightly press the throttle, the car doesn't seem to want to go, i would have to fully press the throttle to get the car going... as if there's not enough pressure in the chambers... (or something like that.. >.< i don't have the technical know-how to really identify what's wrong nor what's happening.. :-p)

Been kept on sending it to ah choy, but still can't put our finger on the problem (we changed the gaskets, the turbo, and the air intake i believe) and the problem still persist...

If anyone out there who's familiar with the problem, please advise... don't know how to fix it... really sad.. T.T

 

[RERider]

do check your solenoid valves and wiring.

 

[jamesweh]

Go and see AH CHOY

 

[Newt]

Thx Re rider,

err.. sorry for this really noob question, but what's a solenoid valve? :-p where is it in the engine? X-(

 

[RERider]

Bring along your RX and come join us this Sunday meet. I'll show you.

 

[Alchemis]

your problem more like a boost leak...
if you're not using any boost controller.. you might want to check your wasgate control solenoid. see if it's sticking open when the hits the peak boost...

 

[RERider]

Newt shd meet Alchemis and phat7 sifu....

 

[elsm80]

ya ya...alchemist also part time tuner.

 

[RERider]

I want him to tune my Power FC.....CB, how?

 

[Newt]

You guys having a meet this Sunday? :-) When? Where? (I can't seem to find it in the treads... :-p) Or do you mean this Monday meet?

Sure, i'd love to come :-) but the car's not really looking good :-p had an accident last year and until now haven't done the paint job X-p still fixing the problems with the engine... >.> so don't laugh when you see it... X-p

Will Alchemis or Phat7 be there as well? Would love to get some advice on all you sifus :-) it's actually not my car, it's my brother's, his forum name is Ryousuke (he had introduced himself in the introduction tread before...) but because of work demands, he's always out of the country, so i take care of the car while he's gone :-p

I'll see if i can take the car up the Ampang hill... >.> The engine's getting pretty bad... It's hesitating like nuts... but will try limping there if i have to.. X-p and i don't think we used any boost controller.. the car is pretty stock...

i wanted to send the car to Ah Choy again, but everytime i call, his workshop is always full, so couldn't really leave the car there... :-( (bcoz i can only come to his shop on weekends.. X-p too busy on weekdays to drop by :-p)

 

[RERider]

Newt, check it out here. Dont worry just come with any car you like. I hope to see you there.

 

[Newt]

Sure, i'll be there ('^,) so far no other commitment.. :-) got your sms already, i know the place (rather familiar with it :-p) so no problem ^^ see ya all there..

 

[Alchemis]

hahahah minor tuning here and there i dare to do la... unless the car is equipped with wideband sensor then can play more with the tunings.

car hesitating.. i think the best thing to do now is replace all the god darn vacuum hoses under the engine bay into silicon hoses... hesitating most likely caused by irregular boost pattern or spark plug worn.

check out the FAQ for maintenance procedures... change oil filter, change fuel filter, clean injectors, etce tc etc... then only we can help and see how to get things futher..

my tip for you to go to ah choy.. be there at 9.30 AM sharp.... saturday... they'll attend ur car when they open up... don't go there 1 PM or 2 PM.. u never get a single oil change done within 2 hour.

 

[Newt]

Thanks for the advice ('^,)

The car has just been recently serviced, but still, will take the car up to ah choy this weekend sharp 9.30 :-) if i woke up by then X-p haha... thanks again evryone for your advice :-)