4G63T spark issues

[REX-ETR]

hey i have a 4g63t out of a vr4 in my cordia, its been sitting for about 12 months now as it has an EPA defect. i started it up and it sounded like it was running on 3 cylinders (sounded like a nug rexy) i checked the plugs they were black cleaned them and put them back in, leads are new, coil pack had corrosion so i sanded it back clean, still no good, put a new coil in, still no good,,ive replaced all vac lines, found boost leaks and fixed them all, cylinders 1 and 3 have weaker spark than 2 and 4, Im running an EMS dualsport with an EMS ignitor, so i wired in a standard power TR unit, it sparked strong across all cylinders, ,, took it for another drive and once i reached full boost 12psi in first gear and changed into second, the moment the clutch is pressed in the engine seems to instantly sound like a rexy running on 3 cylinders..drive it around at 2000 revs for 20 seconds and its back to running on all four strong. i just cant figure it out!!

Im running ,,,

big 16g, stock injectors, ems dual sport ecu and supporting mods.. had been tuned just before being parked up by V&E rigoli

Ive read alot of people had simular problems but no one seems to have posted back with what the cure was..

peace ..

 

[BMGTZ]

try cleaning the injectors

 

[REX-ETR]

hey mate, i could be wrong but i think its on the spark side of things as randomly it will fire on cylinders 2 and 4 strong and weak on 1 and 3, it was doing the same thing when i had the EMS ignitor on it, so i took that out and wired in a power TR unit in its place, it improved spark, but its something electrical i reckon . as its a tempermental problem.. all my wiring to the coil and TR unit is good, ive had a few 4g's but this is proving to be a mission ??

 

[4piknup]

Aren't the coils shared by 1-4 and 2-3?
Spark issues normally show at idle as it is lean then.
How do you know what cylinder is mis firing?
Change coils around to see if that changes the miss. Also, as Brian says. Move/change the injectors to see if the miss moves too.
A lean cylinder will miss and seem like it has spark issues

 

[bazeng]

12 months is easily enough time for your injectors to become sticky... As Brian said... Is it also old fuel? If so, probably stale also, drop the fuel and replace....

Dark coloured fuel = bad. It should be quite transparent...

 

[EVO-00X]

The CAS wiring could be worth checking also. Unglug it and make sure the wires arent freyed. Support the wiring going to the CAS so there's no weight pulling on the wires.
When the engine is moving around or you're pullingon the other wires, it could be cause of the intermittent problem.

 

[Gianni]

I agree above. Sounds fuel related.

Are the injector plugs held down with clips. One might be loose. I've had that before. But I agree with drop fuel and chuck good fuel in and a bottle of injector cleaner.

 

[Liberoz]

check your crank angle sensor and wiring

 

[REX-ETR]

cheers boys ill go and have a play around with it now, ill change the injectors with another set i got here. it had old fuel in it, not much so i topped it up with new fuel looks clean. i've never played with a CAS before, anything i should look out for, all wiring to it is also good. ill give these injectors a go now, does back fire when free revving, maybe leaky injectors ..

suss it out and let yas know

 

[Gianni]

It would t be wiring on the Cas. Generally that would stop car starting.
You turn Cas left to right to adjust. Get a timing gun on it and check timing. Do a YouTube vid search for how to do it

 

[REX-ETR]

hey .. i put another set of injectors in the car, standard blue tops ,, they didnt have a 3 spoke thing in the top of them like the set i took out did, any idea what the go with that is ? anyhow changing the injectors deffiatly fixe the problem, i have my revs back and no stalling. but still no power? and my turbo sounds real funny (turbo is fine) .. still making full boost but seems slower and its still holding back. would a seized wastegate cause this ?

 

[4piknup]

better get a wideband in it now.

siezed open will do it

 

[BMGTZ]

what colour were the injectors you took out?...yellow? your description suggests it is now running lean.

yellow injectors are 510ccpm
blue are 450ccpm....so a lot less fuel is being injected when using these on a chip written for 510s

 

[evo-gsr]

^ I agree with what Brian posted.

 

[REX-ETR]

yeah mate its tuned for the blue tops i just had a spare set.. checked the wastegate today and thats fine .. just missing alot of power

 

[4piknup]

try cleaning the injectors

+10 rep points

 

[Andrews21]

Modify rings around to see if that changes the Missing. Also, Move/ change the injectors to see if the skip goes too. A trim cylindrical tube will skip and seem like it has ignite problems . . . . . . . .