evo 3 ecu on 93 ?

[FLIBYUGSR]

has anyone had any problems with running an evo 3 eco of thier 93 engine ( note: i havea all other botls on from evo thats why im runing the evo ecu )

reason i ask id the car idles a little funny, every few seconds in drops about 300 on the revs then goes back up again

any ideas???

 

[EVOCPE]

Sounds like maybe your TPS hasnt been adjusted properly or your AFM is on its way out... could also be your ECU, open it up and see if any of the caps are poped

 

[FLIBYUGSR]

i opened up the ecu, looks all ok in there

also i pluged in my hks piggy bak fcon, it did idle lower and much better ( for a minute or two) then back to crapy old idle

id like to try a 4g93 ecu see how that goes if anyone has one i could test out?

 

[cblancergsr]

have you checked too see if your idle stepper motor is alright it could also cause the poor idle i had it in my cb gsr and i tested stepper motor and i notice it was running open circuit through 1 coil replaced it and cleared up

 

[VR-4Squid]

check the fault codes too.

 

[cblancergsr]

yes definetly fault codes and air leaks can also do soo

 

[FLIBYUGSR]

how do you check the stepper motor? i could only find a dirgram for vr4 ( different plug? )

 

[cblancergsr]

same sort of idea they are still made up of primary and secondary coils

too keep this sentence short.
1.set multimeter to ohms
2.unclip harness too idle stepper motor
3. check resistence between each pin
4.results show be between 25-35ohms if its a metal bodied iacv or between 35-45ohms if its plastic

also it could be an idea too pull the iacv apart plastic bodied 2 screws at base. metal bodie should be 3 screws on top. reason behind pulling apart sometimes small components inside iacv can corrode and no fault code logged and perect resistence in coils.

 

[progkamol]

hmm .. sounds like the Rover 623GSi I have (or my family have coz my dad paid for it lol) back in Thailand. After the engine conversion the car been doing the same thing on idle. Its very obvious just after cold start in warming up time. It seems to get better when warmed but still does that .. we send it to fix and I'm not too sure what they did but it fixed .. pretty sure the guy didn't mention about ECU tho .. anway .. goodluck mate, hope u can fix it soon

 

[cblancergsr]

as for the ecu it could have a leaking cap but as flibyugsr previously said the ecus circuit boards look good, smell good.

but i agree that it could be afm iacv tps being out of adjustment, could also be o2sensor, tempsensor list could go on

 

[DEVOIX]

What AFM are you using?

 

[FLIBYUGSR]

i am running a evo 3 afm

update : i found an air leak from the connector that the bov connects to, it was loose and i actually pulled it right out myself

i pluged it up wit a small screw started the car and it idles much better

took it for a quik drive goes ok in first then all of a sudden goes to crap, puff of smoke also came out the exaust, idles more like a rex till i turn it off but no more smoke

id like to know could this be a air fuel issie? only therie is have i have the evo fuel pump hooked up via switch dirrect to the battery? could that be pumping to much power to the fuel pump causinf the pump the send too much fuel? or prehaps due ti it being hooked up the way, prehaps the ecu doesnt know how much fuel is being sent?

 

[cblancergsr]

wait you plug the vacuum line from the intake manifold too the Bov. wouldn't that cause problems with air/fuel ration

 

[EVOCPE]

Never heard of hooking the fuel pump up that way

The BOV vacuum should run off the intake manifold usually on the nipple below

 

[FLIBYUGSR]

yea, i pulled that nippple out with my hand ( i aassume that was a majoy air leak, have the bov hooked up to anohter nipple further acroos

 

[FLIBYUGSR]

problem update:

the engine starts ok, idles a little rought, revs up ok, but after a minute or so of runnign the idle goes crap, also rev i try to rev it from the engine bay theres sounds like a knockin coming from inside the engine, and it also shakes around a bit too?

no smoke is coming out of the exasut though

when i shatterd my compresor wheel could the small parts have got into the head? engine?

 

[EVOCPE]

Yes could be that... just out of curiousity check your engine mounts

Take it someone who knows these cars

 

[FLIBYUGSR]

yep all mounts are ok, engine shakes when started and loud knocking, hard to tell form where though, id say top half near the intake

 

[EVOCPE]

Dont worry about the knocking, that would just be the common lifter noises in the mitsu engines, should only do it when its cold and then eventually go away

 

[FLIBYUGSR]

nar, i it does this weird idle where its a loud knocking after a take it for a drive, then stalls.

this engine has me stumped

i am getting a gsr evu tomorow so im goin to plug that it n see what happens,also i will get 510cc and install them, following that i have a mech coming over next week