MadDogWRX

Hi

I am currently having the folowing problem with my `95 WRX (with full decat, K&N Induction, ScoobyECU (1.1bar), NGK 7b`s)

When driving under full boost the car misfires slightly, I am not seeing any knock and the lambalink is showing green for a/f ratio. I have checked all plugs and coils and cannot see anything untoward. Also I`m not getting any error codes.

Occasionally the car will go into `safe` mode holding 0.5 bar, when it does this the car runs very well all the way to the redline with no misfire whatsoever.

Does anyone have any ideas why the problem I am having would only be happening at full boost. Fuelling etc.

Thanks Paul

flat4_ire

could be over boosting? mine does this sometimes too, scoobies are strange, very sensitive to modifications from what ive learned

MadDogWRX

What would be the best way to control this. Dawes device or an EBC?

flat4_ire

i honestly have no experience of dawes device or ebc, but if your car is going into safe mode and boosting no more than 0.5bar then u def have a boost situation, i would talk to someone who knows their stuff sooner rather than later too man ok

MadDogWRX

Thanks v.much for your help.

flat4_ire

ah no hassle wish i cud help ya more

Delboy2

What plug gaps are you running?
If the ecu is defaulting to 'limp home mode' carry out a diagnostics check shown HERE to see if faults have been stored, this may highlight the problem

Cheers

ben1413

iTrader: (5)

I had this on mine - 1994WRX. If you back off the throttle slightly after giving it full boost does it go OK? If so then it will be the fule pump not supplying enough fuel at full throttle. I changed mine and the car is fine now.


Good luck with it!

Ben

MadDogWRX

Ben - Yes, that sounds like it. Did you upgrade your pump to a 255l/h or just replace with another oe item?

Delboy - I have done a diag. check and it revealed no issues. Gapped to 0.7mm (is this OK)


Cheers

Ozzy_B

iTrader: (2)

ah this occasionally happens to my 99 sti, especially in 5th gear, put my foot down quick and sometimes sticks to .5bar, but lift off then slowly put foot to floor and it hits full boost, was wondering why it did that. Luckily enough my cars currently at scoobyclinic so i may aswell give them a ring and get an uprated pump fitted...great more cost

Delboy2

0.7mm is fine Do you have a boost gauge fitted? As mentioned above you may be hitting the boost cut which is normally at 17.2psig as this is the full range of the std map sensor, as the boost target on the scoobyecu is 1.1bar (15.95psig) it is possible you are reaching this - does the 'missfire' only happen in high gears?

Cheers