back firing

[LeedsLad]

my fd has been stood a while and iv\'e just installed a blitz nur spec back box that I got for free:Giggle my car is also de-catted. recently it\'s been idling badly splutering and back firing until it\'s warm and then back firing when letting of the revs. when backing of the accelarator i can understand the back fire but not the poor idle when cold:2Mad , the previous owner said the idle was adjusted when it waas de-catted but not mapped does this sound right.

Also can some one recomend a quite back box i need to change it before i become the most unpopular guy on the street and theres some one who will remain nameless who starts a motorbike at 3 in the morning!:2eek

[Jono FD3]

Oooo, as far as I\'m aware if you decat youhave to remap for the increased flow in the exhaust!!!

Jono

[LeedsLad]

bump.........................................

[Mims]

Dont worry about it its normal for a decat when cold

[chopper2k22]

Have you got a silenced decat or just a straight pipe?

i have a silenced decat on my car with a nur spec box and its loud till its warm then idle its really quiet, unit you accelerate.
Myn also backfires and :flamed

[rmagictastic]

1. Most fd\'s fart and burp on startup as the engine will overfuel until properly warm, dont worry about this.

2. if your running a stock ECU, you really shouldnt run a decat, less restrictive exhausts can cause a multiple of problems without correct mapping, most noticabley whats called \'Boost Spike\'..because you have less back pressure in the exhaust that what the stock ecu Map was designed for, you will see the boost go over the stock 0.7bar and spike, up to a point where the car gets control again and tries to compensate, usually by cutting fuel, which sounds silly, but thats what the stock ECU does!!

Now...the prob with boost spike is that you obviously have more air going in to the engine than the cars ecu is programmed for, as such you can get to a Lean fuel mixture, which can in turn cause damage and possibly failure of the engine.
Think that good enough

AMEN

Rmaj

[Warthog]

Are you running an Apexi + Commander ECU or is it the Stock ecu ?
The Stock ecu is fine if you don\'t mod, you are modding by changing the exhaust system to a more free flow type. So you need to change your ecu so that any mods you do can be mapped safe. With modding and an after market ecu e.g. Apexi, you will see massive power gains as you go through the modding process.
I have just changed from the Apexi to the Motec ecu as I had out modded that ecu. HTH.:wave

[Mark Ide]

Dear Mr Hog
At some stage am thinking of getting a nice stainless racing beat setup when my exhaust rusts away... would that run on a stock ecu with stock twins ok? It\'s an imported type R
Regards
Mark

[chopper2k22]

im running standard ecu, HKS filters, WGT silenced decat n blitz nur spec with a profec boost controller at .8bar and all is fine as its been set up by pip

[LeedsLad]

so remap it is the cars still of the road untill may so no heavy driving. What am i looking at for an ecu and remap 700notes about right?

[chopper2k22]

if youve got a boost controller you can control the spiking, or if you have a midbox put in to give you a bit more back pressure should be ok.
take it to pips and get a reading on the AFR is your best bet, that way you can see clearly and not risk det.
As for poor idling whats it doing ?

[LeedsLad]

when cold its spluttering and jumping revs from about 1k to 2.5k when warm it runs very smoothly. from the coments i take it this is normal but it\'s my first rotary and any unusuall sound,light,smoke requires me to change my underwear. may get a boost controller for now and get an apexi in a few months when my bonus is here. What boost controllers are people using???

Thanks
Adam

[Rixio]

£700-£800 is about right for a remap...£500ish for ECU + £300ish for remap
Who are you planning on taking it to?