think my car is over boosting

it as total engine shut down when turbos cut in

when it is realy warm it seems ok

is this over boost?

 

if so whats the best thing to cure it??

 

steve

whats your boost gauge reading when this happens? and do you have an aftermarket gauge?

standard cr@p gauge goes off scale

tryed after market before fitted induction kit

was reading about 1 bar

 

steve

are there any mods done to it?

if it has suddenly happened try looking under the big inlet pipes at the front of the engine (from intercoolers to inlets).

there is a small pipe each side connected to just under them. these pipes are the wastegate actuator lines i think (???). anyhow, they are where the mig tips go if you are using them to boost it. so if one has come off or split, etc you will have no actuator pressure and it will just keep boosting until the ECU goes "OH, S#'T!!!!" and shuts it all down.

otherwise, try it at less throttle to see if it is boost and not revs.

if you keep it on just enough throttle to be just on positive boost you shouldnt get cut out if it is a boost prob. hope this helps as im not sure i have made it very clear. if you have any queries on what i have said, let me know. thanks. si.:confused:

forgot to mention, if it isnt modded, 1bar is way too much.

it should stay at around 0.7 on full boost.

Has this only happened after you have installed your induction kit?

 

What induction do you have?

 

If you have you are probably having the good old air votex around the MAS problem.

 

Stuart

Originally posted by siraff

forgot to mention, if it isnt modded, 1bar is way too much.

it should stay at around 0.7 on full boost.

 

 

9spi standard which is 0.62 bar I think

its got 1mm mig tips init

ill have a look if the pipes are ok

when the car as had a good run it seems ok

its only started happening since i had apexi filter fitted?

when you floor it it kicks down and goes then just cuts out.

 

steve

could it be an autobox problem?

the box has only done about 700miles

whats the good old air votex around the MAS problem.

 

steve

thanks SRRAE. thought it was 0.7 max on first overboost? mayb just mine. the standard gauge used to read off the end of the clock when it was at 0.7 on the Greddy now its at 1.1bar on the Greddy and the standard one just cries for help.:dance: :D

just noticed, STEVO, what part of gloucester are you in?

:)

cant see it being caused by overboosting. Zeds do not have a fuel cut like many other turbo engines, so the boost will just keep increasing till the engine goes bang.

and CLARKEY, what part of wolves you in? you seem to have my car in my colour in my town. lol

Originally posted by siraff

just noticed, STEVO, what part of gloucester are you in?

:)

 

hi siraff

 

i live in whitminster not far from quedgeley.

 

:D

 

steve

whats the good old air votex around the MAS problem ?

 

:confused: :confused:

 

steve

Some inductions made such a smooth air flow it would cause a vortex around the MAS. The air would flow down the sides of the MAS but leave a vacume or a lot smaller air flow down the middle of the MAS where the actual sensor is. This resulted in the car thinking its not getting much are and compenating for it, while in reality it is getting a lot of air. This resulted in the car stalling particually at higher speeds.

 

The A'PEXi induction has a funel interupting the air flow so it travels past the MAS with some turbulence and evens out the flow, so its not just traveling down the edges.

 

People who are experiencing this problem can help by taping a ball of paper inside to the top of the filter.

 

Stuart

thanks mate

 

do you mean filling the centre hole up??

 

steve

hi mate i think it could be a mas problem but on the other hand i went to see a 300 zx tt and it was doing a simaler thing if u drive it normal without slamming the pedal down and gradualy pick up the boost it was fine but when i slamed my foot down it started ccutting out but as i eased of it went anyway ended up not buying it and i spoke to the guy later and he said nissan said it was the turbo it was cracked or had a leak or something like that so he was getting them replaced also can u hear a hissing sound when u floor it or try to floor it and keep it floored and see what happens because when i floored the guys one and kept it there for a bit it stoped cutting out and went ffast .... how many miles ur car done ...... sorry if i did not explain well enough hope this helps let me know what goes on cheers

I live in Codsall mate. As many will tell you about 2 mins from the Foaming Jug where we held a meet last year.

Originally posted by harry 2

hi mate i think it could be a mas problem but on the other hand i went to see a 300 zx tt and it was doing a simaler thing if u drive it normal without slamming the pedal down and gradualy pick up the boost it was fine but when i slamed my foot down it started ccutting out but as i eased of it went anyway ended up not buying it and i spoke to the guy later and he said nissan said it was the turbo it was cracked or had a leak or something like that so he was getting them replaced also can u hear a hissing sound when u floor it or try to floor it and keep it floored and see what happens because when i floored the guys one and kept it there for a bit it stoped cutting out and went ffast .... how many miles ur car done ...... sorry if i did not explain well enough hope this helps let me know what goes on cheers

 

 

the cars done 150k

its had a replacment engien at 100k

turbos 30k latter

and box 700miles ago

when it cuts out you have yo let the throttle go and after about 5 sec it goes again.

its only started it after apexi was fitted im going to lock at that route.

 

thanks steve

Originally posted by Clarkey

cant see it being caused by overboosting. Zeds do not have a fuel cut like many other turbo engines, so the boost will just keep increasing till the engine goes bang.

 

Wrong, zeds DO have a fuel cut ;) Its not done off boost though, its done off air volume being drawn in through the MAS. Sounds like you either have a boost leak or you are hitting boost cut...

 

CheerZ,

Andy

ah, i stand corrected then.

Originally posted by andyduff

Wrong, zeds DO have a fuel cut ;) Its not done off boost though, its done off air volume being drawn in through the MAS. Sounds like you either have a boost leak or you are hitting boost cut...

 

CheerZ,

Andy

 

thanks mate

whats the best way to cheak for a boost leak then??:confused:

 

steve

Ask Vijay for one of his 'boost leak detectors' ;) This basically fits in place of the MAS and you pressurise the system with a foot pump....

 

CheerZ,

 

Andy

thanks alot

think ive sorted it seems ok now ive

moded the air fillter.

 

steve