sequential issues?

nuki · March 10, 2010, 09:59:26 AM

1995 fd3s stock turbo,downpipe,de-cat,filters,backbox,front mount intercooler,apexi pfc,322bhp mapped by wgt.

Little help if possible please...
Basically having little issues with my sequential twins.
Problems such as

1: changing gear and not having a turbo, then having to gear down then back into the gear to get the turbo back. This is never a problem in 1st or 2nd gear. Seems to be worse on motorway going from 3rd to 4th.

2: When i had the car mapped 3 month ago it was really aggressive at pulling and just doesnâ€™t seem so aggressive anymore..
The boost levels seem fine but just donâ€™t seem right like the turbos not spooling fast enough. Not sure...

If someone could point me in the right direction in quite good detail please or ever had a similar issue would be very helpful.
Thank you.

nuki · March 10, 2010, 12:28:14 PM

any ideas anyone?? thanks

nuki · March 11, 2010, 09:53:30 AM

all random boost levels...

0.74 on nice driving 1st and 2nd gear...
0.84 on hard driving 1st and 2nd gear
0.94 sometimes if im giving some pasty in 3rd gear about 6000rpm
the PowerFC Boost setting i use says...

1: Primary 0.7 52%
Secondary 0.75 49%

nuki · March 19, 2010, 12:26:55 PM

Bump!! Still got an issue! is no one at all on this forum familiar with the sequential system?

Lil-Steve · March 19, 2010, 01:09:27 PM

It sounds like you have a solenoid playing up I had the same problem with my FD.

If there is a massive appreciable loss in power but the boost level is still high it\'s porbably only running one turbo and it will be well out of puff past about 4k rpm.

It\'s relativly normal to see slightly higher peak boost in higher gears due to the engine loading/loss of mechanical advantage (engine has to work harder making more exhuast gas, and also gives more spool time in higher gears hence higher peak boost).

Mine is a \'96 car with the revised rats nest though so the solenoid causing me problems might not be even in you car. The solenoid was underneath the pipe entering the front of the throttle body that goes across the top of the block. little green and black soleoid almost party popper shaped.

Otherwise are there any other strange sounds vibration etc?

nuki · March 19, 2010, 01:33:36 PM

ye its a strange one. Although i always get the kick and overboost on the changeover so i know the 2nd turbos working.

I have just replaced the pressure tank and a blocked check valve.. since then ive not had the problem loosing boost on gear changes.

But the car still dosent seem as fast as it was at all... But still making full boost.

What solenoid would cause a problem even though i am producing full boost?

Thank you.

fil_auto · March 19, 2010, 01:49:25 PM

just a thought - and something that I reckon i\'m starting to notice! I can hear a new little noise, which I can only explain as slightly metallic ( you know what\'s coming don\'t you?! ..... I mean mine flies and hits the right sort of boost levels and all that ) but could it not be that the tubs are slowly on the way out? extra play .... therefore, still hitting boost but not pushing as much / air, therefore exhaust etc.... ??!!

therefore not quite as quick?

Lil-Steve · March 19, 2010, 01:53:19 PM

On mine it was the green and black check valve.

But as for how most of the rats nest works and how it could reduce the power output I remain willfully oblivious.

If you are producing full boost on both turbos and it seems slower it might be worth checking for a boost leak? Even though the boost IIRC is measured at the manifold (?) hence MAP sensor.

I\'m wondering if the random fluctuations in boost have caused it to run lean or super rich and caused some internal damage. Lean cuases det as you know but super overfuel can thin the oil too much and cause bearing and seal damage.

Other causes could be too much exhaust back pressure from a jammed or sticky wastegate/exhaust flap for the pre-spool on the twins. A fried cat full of soot (esp. if you have been overfueling), and a variety of elctrical and spark issues.

I\'d say take it down to you local specialist and get them have a look round it might cost a few bob but for piece of mind and diagnostic skills they will all out do me in all respects.

nuki · March 19, 2010, 01:55:08 PM

Possibly but I have only just put a new turbo pack on and had it mapped end of january and its been sound.

nuki · March 19, 2010, 01:58:55 PM

but sometimes i put foot down it actually feels really fast then other time it dosent.

Lil-Steve · March 19, 2010, 02:02:03 PM

You be able to tell if the turbos are on their way out, if you have decent shaft play you\'ll see the little puffs of oil escaping past the bearings and hence out of the exhaust. Spool up and lift off after being on boost are the easiest times to look out the back window and see it.

Lil-Steve · March 19, 2010, 02:03:42 PM

Quote from: nuki;680358but sometimes i put foot down it actually feels really fast then other time it dosent.

Might be worth changing the leads and plugs if you have spares to see if you\'re getting a bad spark, or pull them out and check the condition.

nuki · March 19, 2010, 02:04:21 PM

Yer i rememebr when my prev turbo pack went and if i stopped driving for 10 seconds i filled the road/motorway whatever up with flooms of white smoke.

nuki · March 19, 2010, 02:05:18 PM

Quote from: Lil-Steve;680361Might be worth changing the leads and plugs if you have spares to see if you\'re getting a bad spark, or pull them out and check the condition.

Ye thanks steve might just do this 2nite when i get back home and take a look at the plugs. i did change them in january before i got the car mapped but i will check anyway

Lil-Steve · March 19, 2010, 02:06:07 PM

It\'s blue smoke for turbos usually unless they are watercooled.

White usually BHG\'s on boinger engines and waterseals on a rotary.