Hi fella members...My friend own a wira 1.5.Now using 4G91 bolt on
turbo using GSR turbo kit.It was ok until now...Suddenly one morning i
start to use,the check engine light still goes on when the engine is
already start...After 15 minutes of warm up,the check engine light goes
on...my friend sent the car back to the mechanic and he change the air
flow sensor...The problem is solve for a while.Now the light goes on
back and it jerks everytime the light is on.my friend sent back last
wednesday and the car is still having this problem.
Do you guys have any idea?

The car spec:
4G91
GSR turbine
wiring evo 3
air flow sensor evo3

try to diagnose by scanner or jump wire. maybe the wiring harness also have a problem.

Agreed..easier to use efi diagnostic mode rather than guessing

the problem is that the car is rojak...so a computer cannot detect its problem code...

i think u have to check the wiring harness.

if the ecu is able to lit check engine light warning it must've detect the problem and register the error code u just have to pull it out from the ecu..if it was a toyota engine there is a diagnostic plug where u simply connect jumper wire between certain pins n read the code by observing check engine light flashing in a certain time interval; cross ref. from toyota engine manual to know the error..even if the engine is rojak 1, at least u know where to start..for 4g91 u have to search the manual 1st tho =)

i think i'll inspect the induction system first, AFM, TB, PCV hoses, plug, cables etc..cheers

4G91 also have diagnostic code, also can jump on the diagnostic socket. i have the code but not with me now. is an OBD1 type.

since the wiring is using evo3 the computer cant recognize any error code...

if the check engine lit up it means error code is registered (same wiring same comp box) no? hmm need to ask mitsu sifu around..

no guessing work when it come to a red light.. just send in a workshop with scanner and you need not to guess anymore...

My cousin face the same problem last time..but the diffrent is, he using 4G93T engine and original wiring harness..after change the computer box, problem setel, no more jerk and engine check on..

just my 2 cents..cheers..

the car is currently not under my guard...
but the problem settle as the computer blow one day...
change new one ok already...