boost problem?

[Baz]

Hi peeps, just been out to play in my fd and when i put my foot hard down it gets to about 5000rpm and i\'m getting what i can only describe as a huge misfire without the bang, i beleive its called boost cut. I tried it on 3 different boost settings on the controller and i get the same result. It stops boost and then it comes back and accelerates well and it happened thru 1st,2nd and 3rd gear. The car is regularly serviced by Geff and well cared for by me. It was mapped a few months ago by Geff and has been fine up till now. I cant find any hoses popped off and all looks normal. The engine was rebuilt 10 months ago and a new turbo(single turbo) was fitted shortly before and has only 3000 miles since and i only abuse it occasionly but this is the first time this has happened. The commander readings are the same as they normally are. I always let it get up to temperature before giving it any teddy and i\'m a bit perplexed by this behaviour.  Can any of you give me a possible cause please.

[rx7veilside]

best to check with geff..mine is also single using profec controller and yesterday i had a boost cut nothing severe i booted in 1/2/3/ and in 4 boost suddenly cut the controller does it if u are exceeding the setting programmed in mine is 1 bar at moment it will overboost slightly but then settle back but on this occasion it dropped it right off to .2 bar boosted fine straight away if a pipe has popped off it wont boost again properly because u wont have full pressure..took mine out today and gave it some clog and all was fine..maybe the wastegate had a mad moment have u tried since..what boost controller are u running and have u adjusted it since the mapping..also with the warm weather u will get increased knock due the higher temps and pfc may have cut ur boost when u booted it what intake temps were u running

[Baz]

I\'m using the blitz dual sbc spec r and the temp was 85-87 as it normally is. I just been out an gave it another go and its still doing it. I\'ve adjusted nothing since it was mapped cos it\'s all abit confusing for me so I leave all that to Geff so it looks like another visit  to Geff\'s is on the cards then.
Cheers for the reply,much appreciated bud.

[rx7veilside]

what i meant was what air temps were u seeing not the water but if it is still doing it then get geff to look much simpler are u getting any boost at all

[Oedipus Rex]

I\'d be really careful mate if it is a boost cut. Effects can be deadly, a boost cut also cuts fuel supply and can lead to real bad det. I take it you only get this on WOT.

What are your boost levels before it cuts?

I really suggest you get it back to Geoff and don\'t boot it \'till he\'s had a look. It could well not be a boost cut and something totally harmless bur better safe than sorry huh.

[rx7veilside]

if running boost controller like profec i think it just cuts the boost as u have a adj limiter that will drop boost to whatever percentage u want..fuel cut is more likely on orig ecu and wld be more dramatic (like hitting a wall)

[Oedipus Rex]

I think it may be more than that though by his.

when i put my foot hard down it gets to about 5000rpm and i\'m getting what i can only describe as a huge misfire without the bang

comment.

Maybe reading more into the situation though, easily possibe.

[dandan]

I just bought my first RX, and FD3S and I have experienced exactly the same thing as BAZ, a real lurch at about 5-6000 rpm which scared the cr*p out of me. it only happens when flooring it, and one suggestion I had from an experienced turbo nutter friend is that the boost is so high it is physically blowing the spark out at the spark plugs, meaning the plugs are getting on a bit. Luckily i\'m getting mine down to Re:worx next friday to find out for sure, but i\'m going to try and fit some nice new cold plugs, maybe this will work for you?