Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: bidoucrx on May 21, 2013, 06:58:45 PM

Title: backfire around 0,8 b
Post by: bidoucrx on May 21, 2013, 06:58:45 PM
hello everyone.

I have a problem with my FC TII
my set: FC3S S5 turbo II
- 3 inch exhaust
- admission
- FCD
- ACV out
- Walbro fuel pump
- Fuel pump rewire

I\'ve tested with the parts of a friend:
- Ignition coils (trailing / leading)
- Airflow meter
- Pressure sensor
- intercooler

my problem:
by being in 3 rd gear (same in 4 and 5) was 2000 rpm I put WOT and the boost pressure take 0.8 / 0.9 b around 3500/4000 rpm, violent backfire arrive

but if I release a little the backfire stop, and I take all the rpm
 
sorry for my bad english :p
Title: backfire around 0,8 b
Post by: bidoucrx on May 25, 2013, 06:50:54 PM
hi people have ideas??
Title: backfire around 0,8 b
Post by: L18M on May 25, 2013, 08:36:32 PM
backfire = :flamed = :Thumbs-up

hehe.. maybe something to do with the ecu as you have a free flow exhaust (no cat?) and fcd. The stock ecu is not mapped for free flow exhaust and fcd.

I say try use higher ron fuel or get a chipped ecu :D
Title: backfire around 0,8 b
Post by: bidoucrx on May 27, 2013, 04:53:11 PM
ok, i\'ll try !
but it functioned very well before! so .... !
Title: backfire around 0,8 b
Post by: L18M on May 27, 2013, 07:23:51 PM
dodgy AFM / injectors / map sensor?
Title: backfire around 0,8 b
Post by: Prof on May 28, 2013, 07:26:54 AM
I think Liam might be right  
 
The FCD will basically lie to the stock ECU and kep the reported boost level down - but 0.8 / 0.9 is quite a way above the stock cut point, so you still might be seeing some boost cut.
 
If you try a chipped ECU, you need to remove the FCD, as that will be built into the ECU\'s mapping.
 
You might also be seeing the 3700 RPM hesitation that\'s well reported on te US forums - I believe it\'s to do with earthing issues causing problems when the secondary injectors stage.
Title: backfire around 0,8 b
Post by: bidoucrx on May 28, 2013, 06:04:42 PM
thanks liam and prof:Thumbs-up
I\'ll try to take another ECU and clean my injectors.
but I don\'t understand why it has started doing these failures, while I have changed nothing on my set.:3Confused