Car running rich, fuel injectors?

hey guys hope you can help me out with this.

since i bought my zx about 14months ago its only a NA and has been running a little rich and slowly getting worse, seems like the engine is getting too much fuel and not burning it all up. tried a few things to try and fix it but not to much luck.

so i took it to a diesel machanic that has been a great help with fixing both of my mum's import cars.

whislt the car was there, one of the previous owners saw the car and asked about buying it back (bad luck for him i aint selling) he also mentioned that he had put turbo fuel injectors in place of the stock ones, so my machanic says he cant really find anything else wrong with it apart from perhaps the injectors.

so my question is, can having turbo injectors in a NA be causing the problem, and i have had a little look around on the internet and noticed different sizes or cc injectors, what ones should i be going for in my car.

thanks in advance, and sorry if its a silly question, only just getting into car machanics.

 

Probably a stupid question, have you checked the air filters?

 

had a different machanic check the car about 6 months ago and he suggested that i change the air flow meter, so i guess he would of looked at that too, will look into it.

forget to mention other stuff i changed.

fuel filter, fuel pump, AFM, change series 1 ptu to a series 2, and oil filter.

think thats all

 

TT injectors are bigger than NA, and if the ECU is not returned then you will be over fuelling the engine. The Lamba will be trying to wind back the fuel but they are probably chocked full of carbon, or are cooked you are probably in "closed loop operation".
Firstly confirm that they are TT injectors and he is not spinning you a story. If so you need to re install NA injectors, or get you car retuned to matche the additional fuelling. Also, changing to TT injectors is not needed on a NA, unless you have significantly modified it, or TT it.

 

i thought it was kinda silly having them on there, the previous owner probably just figured more fuel = MOAR POWARR! i doubt he would have tuned it right aswell. i will mention to the machanic what you said and hopefully he will get it all sorted.

if i got to put some new NA injectors in, is there any one you would recommend?

 

Have a look at the colour of the plastic on the injector body/plug.

I think the NA's are red and the TT's will be a cacky green/brown sort of colour.

 

Stock, secondhand is fine, just have them flow tested and cleaned before installing. Or jump on the sellers that are here for new ones. No need for aftermarket, there are some benefits had from changing to a split spray pattern to aim at the two inlet valves, but this is only in relation to emission compliance and marginlly fuel enconnomy.

 

TT injectors flow much more fuel than the NA ones, if he also got a custom tune to allow for this they may well be fine, if not it will definitely cause problems, not sure if it would even be driveable though.

 

Thanks guys, i managed to track down the stock one that the previous owner had taken out and dropped them off today so they can be cleaned and tested probably monday, hopefully all should be working good soon.

if the turbo ones on it are in still alright condition i will probably be selling them.