Shuddering (boost Issues?)

[KiwiRS4T]

Dry filters are meant to be replaced - you can shake out loose dirt or give it a blast with an airgun but otherwise you need a new one. (bit confusing ...your picture shows a paper type filter??!!)

[scotty nm35]

Its a stainless mesh that filters down to 200 micron, which is just not quite small enough to stop fine silt particles.

Its good for 1000 ps though.

[atomaly]

okay got an update of the situation

payed a visit to scotty_nm35 today and cam (iamhe77) was also there!

we cleaned my AFM, and we changed my spark plugs.

now i know for a fact my mechanic told me shit, cos he obviously DIDNT look at my sparkers or coil packs.

i was told platinum plugs, with standard coils. (just makes me not want to go back now)

we opened it up and saw nice blue coil packs.... turns out i have SplitFires, and they are in good condition from what we could tell!

and the spark plugs were copper.. and model NGK BKR5E-11

we put the NGK BCPR6ES in! (first time changing plugs for me wh00p)

also found that my ECU boost sensor is damaged, the nipple for the small blue hose is broken off, and the hose was just plugged with a screw.

so i need to get my hands on a new one... anyone have one?

thats probably the latest lead on whats wrong!!

the BAD news is that what we did didnt fix the shuddering.. hopefully its the sensor

BIG props to scott and cam for helping me out! u guys are awesome! i owe u one.

Edited December 5, 2009 by atomaly

[wolverine]

as far as i know that only supplies your factory boost gauge. i presume that hasn't been working? mechanics often snap the nipple off the boost sensor when changing plugs with fat fingers and misplaced tools. they plugged it to stop there being a vaccum leak.

the shuddering isn't by any chance different tyres/old worn tyres on the rear causing an atessa issue?

it still sounds a bit like a faulty coil. does the issue happen at idle when warm? if so pull each coil and see which one doesn't affect the idle.

[scotty nm35]

as far as i know that only supplies your factory boost gauge. i presume that hasn't been working? mechanics often snap the nipple off the boost sensor when changing plugs with fat fingers and misplaced tools. they plugged it to stop there being a vaccum leak.

the shuddering isn't by any chance different tyres/old worn tyres on the rear causing an atessa issue?

it still sounds a bit like a faulty coil. does the issue happen at idle when warm? if so pull each coil and see which one doesn't affect the idle.

Only when warm.

I checked the coils for Tom today, no idle issues and drives fine most of the time. He said it seems to be jolting a bit as boost comes on and also up high in the revs. Does the ecu use this broken sensor for mapping?

I assume its the boost sensor for the ecu above plug 6, the sensor for the gauge is in front of the brake booster. Thats the way it is in mine and they are the same sensors.

[scotty nm35]

Thinking about it, the attessa could be the cause, only under power when its transferring to the front. I should have gone for a spin with you mate to diagnose the problem.

[NISSAN GTR]

Thinking about it, the attessa could be the cause, only under power when its transferring to the front. I should have gone for a spin with you mate to diagnose the problem.

Dude it sounds like an ATTESA problem, what size tyres are you running let me know as i found that mine shudder at take off too!

[atomaly]

as far as i know that only supplies your factory boost gauge. i presume that hasn't been working? mechanics often snap the nipple off the boost sensor when changing plugs with fat fingers and misplaced tools. they plugged it to stop there being a vaccum leak.

the shuddering isn't by any chance different tyres/old worn tyres on the rear causing an atessa issue?

it still sounds a bit like a faulty coil. does the issue happen at idle when warm? if so pull each coil and see which one doesn't affect the idle.

from what I can tell the boostguage has always worked! So that must be the

ecu boost sensor which is not pluggged in?

My rears are getting slightly more worn than my fronts come to think of it

maybe I should swap the fronts with the rears?

Edited December 6, 2009 by atomaly

[scotty nm35]

from what I can tell the boostguage has always worked! So that must be the

ecu boost sensor which is not pluggged in?

My rears are getting slightly more worn than my fronts come to think of it

maybe I should swap the fronts with the rears?

A little wear difference should be ok as long as the tyres are the same profile. If the wear is worse and causing issues, you will need 4 new matched tyres.

As your issue only happens occasionally and only when fully warmed up, I would say its something else still. Have you checked tyre pressures? I run 36 psi all around.

[QWK32]

the ecu boost sensor, the one above the engine at the back, only tells the ecu when you hit a certain boost level, its around 1bar, 14psi. and when its met, the ecu cuts the engine i.e. Boost Cut. if the sensors vacuum line is not hooked up it wont cause an issue. i've had to remove the vac line from mine with the turbo upgrade as i kept hitting boost cut. leave the electrical plug plugged in so as not to throw any errors on the ecu.

Edited December 6, 2009 by QWK32

[KiwiRS4T]

NB the boost cut is there to protect your engine. Its only safe to disable if you have an aftermarket ecu, nistune, safc or such like to tune your afrs and you have done so on a dyno with a wideband meter.

[atomaly]

NB the boost cut is there to protect your engine. Its only safe to disable if you have an aftermarket ecu, nistune, safc or such like to tune your afrs and you have done so on a dyno with a wideband meter.

i still presume that is NOT my issue by the sounds of it, from what that sensor does.?

i would plug it back in if the nipple wasnt broken off.!

i'll check my tyres when i get petrol wed. will make them 36psi all round.

anyone else have any other ideas?

would it be worth resetting my ECU ?

Edited December 6, 2009 by atomaly

[kidafa]

would it be worth resetting my ECU ?

Yes would be worth doing it after the plug change and all the airflow cleaning you've been up to.. Put it back into self learn

[kidafa]

would it be worth resetting my ECU ?

Yes would be worth doing it after the plug change and all the airflow cleaning you've been up to.. Put it back into self learn

[atomaly]

sweet! i'll do that tonight when i finish work

[atomaly]

okay some other ideas i've had: going back to the fact that it was fine before it was serviced.

1: could it be the different Oil that was used when they changed it at service? it went from Motul -> Martini

maybe i should try changing back to how it was before it was serviced?

2: could it be an Oil Filter they used?

3: my gear box was also serviced and oil was changed. could it be related to that?

i would think if it was a fuel filter it would happen all the time rather than when its hot?

[QWK32]

okay some other ideas i've had: going back to the fact that it was fine before it was serviced.

1: could it be the different Oil that was used when they changed it at service? it went from Motul -> Martini

maybe i should try changing back to how it was before it was serviced?

2: could it be an Oil Filter they used?

3: my gear box was also serviced and oil was changed. could it be related to that?

i would think if it was a fuel filter it would happen all the time rather than when its hot?

1: the engine oil wouldn't be the cause.

2: neither would the oil filter.

3: gearbox oil could be, do you know what the put in it. too thick and the gears may struggle to push the oil away when they mesh.

when it start shuddering does the engine sound like its struggling, slightly stalling. does the engine tone cut in and out? if the engine sounds fine and runs a treat even when the car is shuddering it would definitely be a g/box, 4WD, or diff problem.

[atomaly]

1: the engine oil wouldn't be the cause.

2: neither would the oil filter.

3: gearbox oil could be, do you know what the put in it. too thick and the gears may struggle to push the oil away when they mesh.

when it start shuddering does the engine sound like its struggling, slightly stalling. does the engine tone cut in and out? if the engine sounds fine and runs a treat even when the car is shuddering it would definitely be a g/box, 4WD, or diff problem.

i'll have a listen to see when i go for a drive next! i have a feeling the engine is going strong still when it happens, but i'll check to make sure..

i do know we discussed putting redline in it, but he went for a thinner martini oil as he said redline might be too thick.! (i think)

[RBPOWA-(TJ)]

check sig. . . .and ring and book. . . but dont expect this year

[atomaly]

i went to reset my ECU using the "bridging pin" method last night (nissan way?).. haha would help if i can find the right plug.

i've never tried this method and i failed miserably at finding the right bit.

anyone else done it that way before??? if not i'll just disconnect the battery for a while.... (remove the positive right?)

Edited December 9, 2009 by atomaly