Missfire at 6700rpm

HKS111

HKS111

Member +
Hi Guys

Specs as below:

td05-16g
emanage ultimate
550 cc injectors
running 0.6 bar for the moment

The car was fine before with stock injectors but then just changed to 550cc coz i want to push more than 1 bar.

The car drives fine below 6700 rpm but then as soon as i reach 6700 rpm it misfires. So far i've changed spark plugs (standard range 6), spark plug leads, distributor cap, rotor. Mapping is fine. Even tried to add more fuel but it runs really really rich.

I'm out of ideas, please help!!!!
 
A

AdamB

Member +
Whats really rich? Whats the AFR? Whats the fuel pressure?
What is your target boost? 550's are a bit big for 1 bar on a td05.
 
HKS111

HKS111

Member +
AdamB said:
Whats really rich? Whats the AFR? Whats the fuel pressure?
What is your target boost? 550's are a bit big for 1 bar on a td05.
Click to expand...

9.8 AFR.
I'm still using the stock fuel pressure regulator.
Target boost: 1.4 bar
 
E

elison

Member +
Thats not missfire. Thats the engine being fluded. Get that 9.8 sorted out and you will get rid of the problem. And mostly a 9.8 afr could also be a lower number because most afr units dont read below that. And also be aware that stock rev limit is 6800
 
HKS111

HKS111

Member +
elison said:
Thats not missfire. Thats the engine being fluded. Get that 9.8 sorted out and you will get rid of the problem. And mostly a 9.8 afr could also be a lower number because most afr units dont read below that. And also be aware that stock rev limit is 6800
Click to expand...

It's not at 9.8, i added fuel to see if it was not getting enough fuel, it's then that i got 9.8 but normally it's at 10.9. I'm pretty sure the rev limit is at 7200rpm and not at 6800 as it was going to the rev limit at 7200rpm before changing the injectors.
 
A

AdamB

Member +
HKS111 said:
It's not at 9.8, i added fuel to see if it was not getting enough fuel, it's then that i got 9.8 but normally it's at 10.9. I'm pretty sure the rev limit is at 7200rpm and not at 6800 as it was going to the rev limit at 7200rpm before changing the injectors.
Click to expand...


10.9 is still very very rich for that setup. I would only use that kinda AFR when going outside the operating efficiency of the turbo.
You should be aiming for an AFR of somewhere between 11.6-12.2.
 
HKS111

HKS111

Member +
AdamB said:
10.9 is still very very rich for that setup. I would only use that kinda AFR when going outside the operating efficiency of the turbo.
You should be aiming for an AFR of somewhere between 11.6-12.2.
Click to expand...

It was mapped at 11.3 before but then at 6700rpm it was missfiring/cutting out. I know its very strange but when i added fuel it stopped and i could go to 7200. some guys overhere told me that its down to bad fuel quality (ron 92 i believe but not totally sure).
 
G

gorganl2000

Lifer
adjust your plug gap to around 0.5mm - 0.8mm and try again
could be simple spark blow out at the higher rpm

also, try a colder plug....maybe grade 7 or 8.,,,,reduce the chance of detonation
 
Franza1

Franza1

Supermoderator & Area Reps Manager
Everything Points to Ignition system, Check Plugs, Plug Gaps, Dizzy, Rotor, Leads, Coil ETC.
 
HKS111

HKS111

Member +
Could it be be that i need to put in the injector lag times? I left it blank in the EMU as i have no idea of the lag times for the 550cc injectors i've got. They are from an RX7 (colour - pale blue)
 
HKS111

HKS111

Member +
At 0.6 bar with stock injectors, there is no missfire at 6800rpm. But with the 550cc, it missfires again!!

Help, anyone please??
 
R

Rev

Member +
Can you give some more info on the injectors. I cant see light blue colour for rx7 primary injectors at 550cc unless they are remanufactured types ?
Stock examples -
89-91 RX-7 TURBO 550cc - high impedance purple top #195500-2020 ( look red in the photo ) Lag time 0.73ms
Denso 550cc inj 2ohn low impedance type lag time at 14v is 0.64ms without peak ane hold driver 0.34 with peak and hold driver.
Also some injectors are only intended as secondaries and will have a separate number stamp on them.

Some 700's were pale blue :)
 
HKS111

HKS111

Member +
Rev said:
Can you give some more info on the injectors. I cant see light blue colour for rx7 primary injectors at 550cc unless they are remanufactured types ?
Stock examples -
89-91 RX-7 TURBO 550cc - high impedance purple top #195500-2020 ( look red in the photo ) Lag time 0.73ms
Denso 550cc inj 2ohn low impedance type lag time at 14v is 0.64ms without peak ane hold driver 0.34 with peak and hold driver.
Also some injectors are only intended as secondaries and will have a separate number stamp on them.

Some 700's were pale blue :)
Click to expand...


Thanks for the info.

Unfortunately, issue still exists. Now i know it's not the lag times as i tried with some sard 460 and still the same issue.

Also tried another known working distributor, coil, igniter, rotor arm, colder spark plugs, gapped spark plugs, plug leads, map sensor.

Also tried another emanage, same result.

Really don't know what to try anymore!!!!
 
You must log in or register to reply here.
Top