ok iv been having this strange idle in my evo 4 since i got the thing... today i tryed the following..
1 started car with air flow meter plug'd in
2 took plug of air flow meter
3 car run better without air flow meter on high rpm but alot better no bump in idle??
4 video it before and after.

http://www.youtube.com/watch?v=IOFNyuymL0Y

 

anyone??? please

 

I wouldn't advise running it without the Mass Air Flow Meter. The car needs that to know what its doing.

If you unplugged it and the car ran better, I would say that its either dirty and needs to be cleaned, or your tune sucks and needs to be looked at?

Are you throwing any trouble codes or check engine lights throughout any of this?

 

hey thanks for the reply. yea im not driving without it. its really strange yesterday i done the same thing and it ran worse?? then i reset ecu and did again and it ran better without it on?? iv cleaned it with maf cleaner and nothing if anything made it worse should i just get a new one and hope for the best lol.. also on another note before i noticed all of this i took the car for a hard run full boost and it cut out with a big puff of black smoke? around 6k rpm it hasn't done it since it was not speed cut as i was only doing 100kmh

 

oh and also no check engine light unless i unplug it.. im getting a code reader in a few weeks so i can try and track the problem.. it just really worrying me as i cant afford a rebuild again! im sick of the pop and fart on idle my local mecahinics suck they keep telling me its ok! iv had timing checked all sweet. its running lower than standard boost its sits around 0.6bar or is this normal for evo 4

 

ok cars still doing this weird idle thing its got a back fire when going slow only some times idling rough. iv put an evo 7 air flow meter on will it work? i mean what real differences would there be. iv got new spark plugs coming. im going to oil up my hks air filter with k&n filter oil. iv moved my battery and put straight piping to turbo on fuel filter is replaced new rad coolant oil and filter fresh 98 octane petrol all way use.. still doing rough idle. kind of like this... burrrrrrrrrskipbrrrrrrrrrpopbrrrrrrrpopbrrrrrrrrrr rpoppoppopbrrrrrrpop.. lol i really need this sorted im not rich cant afford a tuner!! i don't see how my tune could be bad as its factory

 

Chris. Sorry to hear that you haven't sorted this yet m8.

1. I'll advise you to check out lancerregister.com as they're going to be infinitely more familiar with E4's than most anyone on here.

2. Do you KNOW for a FACT that your vehicle doesn't have a tune on it? The E4's ECU isn't exactly friendly to access, so it wouldn't surprise me if someone had a standalone hooked up to it, and then removed it without you being made aware.

3. Have you done a boost leak test? Thats something I would check as well as this rough idle, and low boost seem to indicate something like that.

4. Running the hard pipe intake isn't advisable on this car right now m8, because hardpipe intakes have been known to make 4G63s idle a bit wonky. So for the time being, at least until you sort the problem, stick with the stock air pipe. I might even advise you to reinstall the stock airbox completely.

5. Have you checked the compression on all cylinders m8?

Seriously though... hop over to lancerregister and see if they can offer you some help. Tell them that EvoM sent you their way.

Good luck m8!

 

Also, just watching and listening to this video, this idle sounds fine to me? However... videos rarely translate the sound as well as being there.

 

yea i no it sounds ok in that one hahah but yesterday it stalled twice on me. and when i sit there a push the brake pedal the boost gauge goes up and down is that normal? the engine rocks and stumbles when you watch it running ill try get a better video up. and i noticed i can here when it starts running crazy it makes like pop kind of noise in the engine bay? also will the evo 7 air flow work? as when i unhook the evo 4 one while car is running it runs better idle is high but is way smother!! no bumping no farts lol

http://www.youtube.com/watch?v=W0bhnQRF6Ug

 

oh yea and no i have no idea about ecu all i can see in there is thats its a steel box? i no bugger all about the ecu's but im going to get evoscan and see if i can pin point it?>

 

Chris...

1. Try doing the boost leak test.
2. I'm not positive if Evoscan will run on the E4's? I think the E5 is the first version that was able to be flashed/read? But I could be wrong... the chaps on lancerregister will have better info.
3. Stepping on the brake pedal in the E4 is probably going to show a vacuum fluctuation because of the master cylinder... but I'm not 100% on how this system functions off the top of my head.
4. I'm fairly confident that the E7 MAS will NOT work with an E4 due to the slight motor differences. I actually think the E4 can only run the E4 MAS because of the E5 and E6 differences. Again... the lancer register fellows will be much better at giving info on this.
5. The car may just have its idle set incorrectly, or one of the idle controllers could be damaged, though that should throw a code. Unplugging the MAS is giving you better idle because it raises the idle into a safe mode. It is NOT better, and it is NOT safe without the proper software modifications.

So...

Do a boost leak test.
Post up on MLR.

 

I can definitely hear the popping in that last video. Do you have an aftermarket throttle body?

 

dude i think iv fixed it!! i put some new ngk iridium ix's heat range 7 and huge diffidence the old plugs where ngk platinum heat range 9!!! so the coldest you can get i think wtf????????? but no my idle is around 1k? lets say if i screw it all the way in how many screws back will i need to get it at 900?

 

Ah m8! The plugs were the wrong heat range! This could well have been it. I'd suggest disconnecting your negative battery terminal and letting the car sit for a bit, and then reconnect it. This will reset the ECU. Once this happens, take the car out for a drive after letting it idle to warm up. Get it into boost easily over a few pulls, and see how it runs. If things seem alright, then do a couple into higher boost.

This will help get the ECU to adjust the maps appropriately, and you'll see that idle come down. The ECU is idling it high, it has nothing to do with any of the adjustable sensors. Let it learn and it will sort itself out. Shouldn't take more than a half an hour.

Let us know m8!

 

did everything was running awesome not rough idle engine not rocking about put old intake back on. put water feed to turbo clip on "had came off" wtf? did the reset. was driving good this morning then when i went out this after noon it nearly cut out going around a round about at 40ks. then ran ****ed up again. then when i got home it was idling bumpy slightly i think the air flow meter is stuffed its used a heap of fuel today to. then i had it idling on drive way and turned it off turbo timer kicked in and it nearly died 3 times within 30secs the hks turbo timer is set to. im getting to the point with this thing that im going to selling it and get the early version again i never had any problems with my evo2 or 1.8ltr gsr turbo.. im happy that the spark plugs have stopped the popping and bull ****. but this random cutting out then coming back on is crazy like first thing in the morning you cannot just drive of from cold as it will have no power! and you have to quickly clutch to stop it stalling. i all ways warm up except when im in a hurry ie late for work