Blu_SmUrF

Hi all,

Recently I've started experiencing some hesitating (car feels sluggish and sort of rocking backwards and forwards) on 15psi and above on factory turbo. It's not a boost/fuel cut, it feels more like spark blowout. I've changed my spark plug gaps from 0.6mm to 0.5mm (which helped a little bit) which makes me think its an ignition problem. Though I have swapped a friends coils and leads over to mine and that didnt fix it. My spark plugs only have about 4 thousand kilometres on them (BPR7EIX) though I have some new ones on the way and will test with them

I have alrready done a boost leak test, there was two very slight leaks, one at BOV and one at wastegate actuator, which I have fixed but still hesitant. I dont have a wideband to check AFR but I will be taking it to a local dyno to check AFR. Any other ideas?

Mods:
Walbro intank fuel pump (2 months old)
Turosmart FPR 800 fuel pressure reg set to 44 psi base pressure
3" intake into turbo with hks foam filter
3" exhaust from front pipe back
Factory fuel and ignition maps

LCS

iTrader: (9)

Did you check the coils wiring and grounding?

fugiwara

iTrader: (124)

car leaned out, could be very dangerous to the motor, take to a dyno asap

Blu_SmUrF

LC5: Not yet, good point, I will inspect the wires that go to the coil packs as an earth might not be connecting properly and so not giving a good enough spark


fugiwara: Yeah I will take it sometimes this week, meanwhile i'm only running low boost

Blu_SmUrF

Update:
Finally got my wideband and installed it, car is running very lean on boost, anything above 8psi and 5000rpm it leans out to 14.9.... scary

Things ive tried:
-I've bypassed the low voltage fuel relay and made the fuel pump run at full voltage the whole time, didnt fix it

-I've clamped the FPR return hose for a second and fuel pressure shot up on the gauge to over 100psi... meaning fuel pump should be up to scratch? This was with fuel pump relay 2 bypassed. With the relay not bypassed, pressure shoots up to 85psi when clamped which also seems to be ok. I've checked AFR on wideband and car runs rich for a few seconds when I do this

-I have connected compressed air (20psi) to the FPR inlet to see if the fuel pressure rises on the gauge and it does, however when I did this, the AFR didnt go richer at all? Could it be that the FPR is not working properly? So when positive manifold pressure is being applied to the FPR its not actually increasing rail pressure to inject more fuel?

-I have rescaled my factory 560cc injectors to 450cc in ecuflash but that just made my car run richer under low load conditions

My MAF hasnt been rescaled for the intake pipe I have though, but that shouldnt make the car THAT lean, it has always run good with it, the rest of the fuel trims seem to be ok, just WOT under boost is too lean

Things I still want to try: new fuel filter and try and check FPR psi when under boost while driving

Suggestions?
-

Blu_SmUrF

anyone?

RJSP

Hi Blu Smurf, try this site for more info on early Evos:

http://www.geekmapped.com/forums/

You could also have a fuel pump issue, check that and get a walbro if you don´t have one already. Keep the injector scalelin at 542 for the Evo V. I used to have problems like that and it was either the fuel pump, bad plugs, bad connection in the Maf and Maf plug, or Cam angle sensor.

If you are going lean steadily then it is most likeky the fuel pump, if it only goes lean for fraction of a second (viewed via logs) then it could be plugs or electrical/sensor problem.

Check this instrucctions for reading the fault code, that will narrow down your search for a solution (post 55):

http://www.geekmapped.com/forums/sho...?t=2474&page=6

Good luck,

Ricardo

Blu_SmUrF

Thanks RJSP, I'm already a member on that forum, I'm running a ceddymods modified rom

I already have a walbro, installed it 2 months ago so hopefully its not the pump but I guess it could be a possibility... thought I've done some fuel pressure tests and it seems to be ok

I am going lean steadily and staying lean on higher RPM/boost

I am logging via evoscan and no trouble codes are coming up, I will try jumpering pins anyway and see if any trouble codes come up

Thanks for the help

RJSP

No problem, if you get no codes via joining pins 1 and 4, then it´s most likely your walbro pump, I´ve had 2 of them go bad in a couple of years (maybe they where knock offs)... My current one is holding up fine.

A friend of mine just had the same steady lean situation at boost and we tried giving it more fuel via fuel map and a 1.5 change afr in the map still only resulted in maybe .1 to .3 change in wideband afr, which would stay at arouns 13.5... He change the walbro and problem solved.

Good luck,

Ricardo

Revolution9mr

iTrader: (4)

What was the problem ??

Blu_SmUrF

It ended up being a blocked fuel filter, the insides of it literally started disintegrating and blocking the flow of fuel

Evo 7 and up doesn't have the fuel filter in the engine bay like Evo 4 to 6