backfire/smoking problem

[jdunbar10]

ok so the car has bee running great up till just 10 mins after i filled up at ESSO
of course i use prem. gas and not reg crap

but just after it started back firing every time i let off the gas or sometimes down shift, does not do it when i boost or anything, but also smokes when im at idle for a light or something but wont smoke when i first start it up and let it warm up

i have not checked the turbo yet but it is a brand new mitsu evo16 with like 3 tanks of gas used on it, and about to check the compression just thought i would throw this up before i start checking
but i dont think its the head gasket or the turbo..

any help ?

 

[joegamma1]

Are you throwin in new plugs while your at it?

 

[jdunbar10]

Are you throwin in new plugs while your at it?

already got new plug in about a month or so ago
but if nothing else i guess i could try that again

 

[99gst214]

Have you done a boost leak test? Also are you using a logger of any kind? SafcII or dsmlink? Any CEL (check engine lights)? Most of the time the back fire and smoke is caused when running rich.

 

[jdunbar10]

Have you done a boost leak test? Also are you using a logger of any kind? SafcII or dsmlink? Any CEL (check engine lights)? Most of the time the back fire and smoke is caused when running rich.

no logger, no CEL and nothing for tuning system.

the car is very basic this is a new one i just picked up few weeks ago and have nto had a chance tomess with it at all really

all it has are 575 injector, k&n filter hard uip evo16g boost set at 14psi and a crappy narrowband (yeha i know its going for a wideband)

i just have not had a chance to mess with any of it just yet

 

[99gst214]

no logger, no CEL and nothing for tuning system.

the car is very basic this is a new one i just picked up few weeks ago and have nto had a chance tomess with it at all really

all it has are 575 injector, k&n filter hard uip evo16g boost set at 14psi and a crappy narrowband (yeha i know its going for a wideband)

i just have not had a chance to mess with any of it just yet

I would do a boost leak test and see what you find out. Ya a wideband would be helpful right about now!!!

 

[BIRDCLAWTSi]

With the injectors you have it will run rich with no control.

 

[jdunbar10]

I would do a boost leak test and see what you find out. Ya a wideband would be helpful right about now!!!

yes it sure would

and birdclaw its been running fine for about 2 weeks that ive owned it with these injectors, still think that might be it? i know its been rich but not this bad
( thats asking for help not back talking )

 

[jdunbar10]

ok so here is the update...

swapped back to my 450 injectors,
did a compression test and got 156 156 158 158
so its not the head gasket, no oil in coolant...

going to pull the o2 housing tomorrow but thats where i stand so far...
any more help?

 

[BIRDCLAWTSi]

ok so here is the update...

swapped back to my 450 injectors,
did a compression test and got 156 156 158 158
so its not the head gasket, no oil in coolant...

going to pull the o2 housing tomorrow but thats where i stand so far...
any more help?

Did the stock injectors help?? Also do you have a logger? Your TPS (throttle position sensor) could be out of adjustment. When you let off the gas the tps might be telling the ecm that the throttle is still advanced. Also a throttle cable that is too tight could do the same thing. There is a way to check the tps with a voltmeter,Do you have the manual?