EVO2 idling problem

[bb1-man]

ISC huh. how much were u charged for the unit? is it easy to find?

Im trying to find the 'low cost' cure first before moving to higher cost ones like ECU. although i might have to find a new ECU anyway.

anyone out there got spare aa?

 

[boyzone]

Guys,
Actually I 'm also encounter this problem sice my first 6A10 install.
And it was con't occurred in my second 4G91 engine until today my third
mivec engine . Actually what wrong with Mitsubishi engine ??
When air con turn, drive for some distance, clucth press in to change gear,
RPM will drop until engine die .... help .. Is it ISC faulty ?? impossible, because i have change
the but problem still the same. Of cause something wrong .. pls adv

 

[bb1-man]

wow. This sounds like a big mitsubishi engine mystery since no solution has been posted yet. Only big suspects are:

1) FICD
2) ISC
3) throttle body

my case so far, serviced throttle body. problem still occur but not so often as before. once every 2-3 days now.... talked to a mechanic today and he suspects FICD. will update when i know more.

 

[cb70]

Guys,

I've read this article (similar to my case) somewhere & lets discuss it together,

"...Since the engine idles well with the air-con on, we can assume that the idle bypass valve is working & feeding enough fuel to keep the engine revs up. However, since the engine has difficulty in idling withour the air-con, one of the place to look at is the throttle position switch on the side of the throttle butterfly. With the engine off & the throttle fully closed, move the throttle slightly open; you should hear a "click" when the switch activates. If there is no click, that would mean there is insufficient fuel for idling and the switch will need to be adjusted to activate. If you get that adjusted correctly and still the engine is not idling properly, you may have to adjust the mixture screw on the air flow meter as it may have closed in too much due to wrong adjustment of the throttle switch. These are the two likely sources of the idling problem..."

What is "throttle position switch"? Where is it located basically? Is it similar throttle screw?
What does it "meant by move the throttle slightly open"?
What is "mixture screw on the air flow meter"? Where is it located basically?
What does it meant by "and the switch will need to be adjusted to activate"?

Thank guys.

 

[J101]

Hello ACBC

Are you still running with the unplugged ISC? How bad is the FC as you mentioned as in before and after?

Thx

I unplugged the ISC cable and RPM shot up to 2000 but very unstable. However, with AC switched ON, it drops to 1500 and with some adjustment to biss screw, I managed to bring it down to 900. Not bad... car is smooth, traffic lights also smooth n no vibration.

However... I did notice 1 thing... FC is HIGH! And AC won't cut on high RPMs.

 

[J101]

Hi BB1-Man

I think the best way to troubleshoot this is when the air-con is off. Since the FICD would help controlling the idle during when a/c is on which sometimes the engine dies off even with the help from FICD.

My list would be if its a bad idle at low rpms :
(1) ISC (stepper motor)
(2) Dirty throttlebody
(3) Worn out throttlebody gasket
(4) Loose TPS bolt
(5) Fuel leaning out at , modded cars with injectors, cams, etc

Maybe there are more to it that i dont know, probably others might wanna share their similiar experiences regarding this.

Cheers

wow. This sounds like a big mitsubishi engine mystery since no solution has been posted yet. Only big suspects are:

1) FICD
2) ISC
3) throttle body

my case so far, serviced throttle body. problem still occur but not so often as before. once every 2-3 days now.... talked to a mechanic today and he suspects FICD. will update when i know more.

 

[bb1-man]

thanks for the input J101. My car just rolled out from workshop:

1) ISC replaced
2) Throttle body replaced

so far so good. but im still in 'testing' phase. Touch wood. Lets hope this solves the prob.

 

[boyzone]

That's mean is a completed throttle replacement la ?? Is it included TPS ??

 

[acbc]

ISC huh. how much were u charged for the unit? is it easy to find?

Im trying to find the 'low cost' cure first before moving to higher cost ones like ECU. although i might have to find a new ECU anyway.

anyone out there got spare aa?

Used ISCs are pretty cheap... costing as much as RM 10 per piece. I bought like 20 units for cheaps... around RM 100 everything. Out of the 20, only 2 confirmed OK. Craps!:angry_smile:

 

[acbc]

Guys,
Actually I 'm also encounter this problem sice my first 6A10 install.
And it was con't occurred in my second 4G91 engine until today my third
mivec engine . Actually what wrong with Mitsubishi engine ??
When air con turn, drive for some distance, clucth press in to change gear,
RPM will drop until engine die .... help .. Is it ISC faulty ?? impossible, because i have change
the but problem still the same. Of cause something wrong .. pls adv

Sometimes the ISC controller in the ECU may have fried. Need to find similar ECU n replace the faulty item.

 

[acbc]

Hello ACBC

Are you still running with the unplugged ISC? How bad is the FC as you mentioned as in before and after?

Thx

Yes. My car consumes RM 80 @ 300kms but with ISC unplugged, I'm left with RM 80 @ 200. That's for normal daily driving with minimal boost. But, idling is damn smooth n problem free.

I believe without the ISC, the A/C will remain constantly switched ON and this put some load to the engine.

 

[boyzone]

Sometimes the ISC controller in the ECU may have fried. Need to find similar ECU n replace the faulty item.

huh ??? how to find ?? Pls advise ... Thanks.

 

[J101]

boyzone,
it would be best if you could just buy the whole TB with the isc and whatsoever attached to reduce the cost and effort looking around.
since the ISC comes with few wires to the ecu, the mechanic should be able to tap the voltage to the ecu, if it dies on the ecu side.
better if you have a spare for it incase u need them next time.

bb1-man,
keep us updated.

acbc,
where did u get a whole lot of isc? hehe 20 is too much. haha.
the 100km without the isc is bad i think.


good feedback. thx.

 

[boyzone]

any feedback ??

 

[bb1-man]

bad news. The "RPM drop till dead when approaching stoplight" problem happened again. It happened when engine is hot (after 150+ km of town driving and aircond on). So i suspect it has something to do with FICD which is related to aircond system.

So far ive done:
replace TB + ISC

So next up is FICD and check aircond compressor wiring.

If aircond off, no problems with idling at any time.

 

[boyzone]

totally like my case ....

 

[carmancar]

I have this problem everytime i need to change my Air Filter. After change then problem solved. U can try ... :regular_smile: Good Luck ...

 

[acbc]

Where on earth is the FICD? I may need to rip the TB apart n look.

 

[boyzone]

sometime really make us confuse, if step motor is in good condition, why still encounter die off issue ??
like myself, even though with new throttle body and isc, problem still exist.
something wrong ....
I also look for FICD to replace my isc .. hope can solve my problem ..

 

[alvon_chu]

your ecu got air con cut off checking feature? maybe ur ecu got problem? just my 2 cent, i am facing the same problem, open up the ecu, 2 of the capasitors(or whatever it called) fried