Mazda Rotary Club

General => General Technical => Topic started by: R1Dude on August 09, 2011, 01:53:55 PM

Title: Massive misfire
Post by: R1Dude on August 09, 2011, 01:53:55 PM
Hi all, I have just bought a 92 fd which has been converted to non sequential running twin hks air intakes, de-catted and kakimoto exhaust (only modifications from standard). The engine was re-built using brand new rotor housings and every seal,tip and spring replaced with brand new components. I have had engine was compression tested having 9.5 bar or around that figure on both rotors.

        Now the problem I am having is as soon as it hits boost it misfires badly, spitting flames out the exhaust so I have no power, now if it is standing still and I rev it gently up to 7k it gets there but if i plant my foot it coughs and splutters and no revs same as if I`m hitting boost.

       So far I have changed the turbo`s for a set I took off my other car that I knew were very good, new plugs, leads of my other car that are good, spark igniter, coils, fuel injectors, fuel pump, ecu, boost sensor, all vacum lines, all boost pipes, crank angle sensors, I have checked that the conversion has been done correctly and it has and the problem is still there, I don`t want to break this car but if I cant fix it then I will be forced to so any advise off you guys will be much appreciated :)

Regards Ade
Title: Massive misfire
Post by: m1tch on August 09, 2011, 02:18:03 PM
Perhaps an issue with the coils or a leaking injector? When were the spark plugs changed?
Title: Massive misfire
Post by: R1Dude on August 09, 2011, 02:20:28 PM
Just mate they are brand new, cheers Ade
Title: Massive misfire
Post by: MaLicE on August 09, 2011, 03:12:21 PM
what ecu? you have checked the map sensor is connected correctly haven\'t you??
Title: Massive misfire
Post by: PDale on August 09, 2011, 03:15:27 PM
Are you running the standard ecu with the filters and a decat exhaust?
Title: Massive misfire
Post by: R1Dude on August 09, 2011, 03:37:03 PM
Map sensor is definiatly correct, it does have a standard ecu, thanks again for the replys guys :cheers
Title: Massive misfire
Post by: B.Martin on August 09, 2011, 03:39:40 PM
You need aftermarket managment mate, driving it on standard ecu with said mods is a bad idea. Can cause boost creep, engine to lean and pow...

big bills £££££££££££££££!
Title: Massive misfire
Post by: R1Dude on August 09, 2011, 03:50:26 PM
Damn! was hoping not to spend any money on this one and just sell it on, I used to run an Re Amemiya ecu on my other car before I went to apexi but sold that ages ago, what would anyone recommend? dont really want to spend much on this as it`s just to make money on, cheers guys :cheers
Title: Massive misfire
Post by: HaywardRotary on August 09, 2011, 03:50:38 PM
It\'s on default if its a stock ecu.
Title: Massive misfire
Post by: trotter on August 09, 2011, 04:36:21 PM
Quote from: R1Dude;781067Damn! was hoping not to spend any money on this one and just sell it on, I used to run an Re Amemiya ecu on my other car before I went to apexi but sold that ages ago, what would anyone recommend? dont really want to spend much on this as it`s just to make money on, cheers guys :cheers

unless you want to strip everything back off to get her running right, a mappable ECU is the only way to go im afraid. A brand new PFC will set you back £500 or so, but if you get it with the Commander then it\'s £700 IIRC. Then a remap will set you back about £250.

Sorry to be the bearer of bad news bud, but if you keep boosting like that you\'re gonna break something :(

HTH

graeme
Title: Massive misfire
Post by: R1Dude on August 09, 2011, 09:55:35 PM
Mr hayward sir you are a legend, working sweet as a nut now, can`t believe I forgot about that, tax mot and its up for sale :Thumbs-up thanks again :cheers
Title: Massive misfire
Post by: splinter53 on August 09, 2011, 10:14:47 PM
Could it be running lean? As it\'s on standard ecu and not mapped properly?
Title: Massive misfire
Post by: m1tch on August 09, 2011, 10:22:31 PM
Quote from: splinter53;781170Could it be running lean? As it\'s on standard ecu and not mapped properly?

The fueling and boost won\'t be controlled or managed properly on a stock ECU, the engine will go soon (like many engines that run with a decat, exhaust and intake with OEM ECUs)
Title: Massive misfire
Post by: R1Dude on August 09, 2011, 11:49:47 PM
I`m selling it back to the previous owner, I have informed him it needs an apexi and mapping properly otherwise bye bye engine, thanks for all the advise ppl :cheers