Mismatched injectors on 182 - more than one option?

[Codfather]

My 54 plate 182 began misfiring last weekend and then got steadily worse to the point of being near constant.
This weekend I decided to start inspecting fueling/ignition components as the OBD reader came up with "no codes" despite the engine management light being on.

Pulled the fuel rail out and then found that three of the injectors are the Magnetti Marelli standard OEM units, whereas the fourth is a completely different size and shape.

Does anyone know if there is more than one acceptable OEM injector? I struggle to believe there would be two so dissimilar.

My plan is to replace this with OEM, but as a sanity check before hand it would be good to hear whether or not there are two different acceptable types.

Had the plugs out and they're dirty-ish, but the electrode gap is on the slightly wide side of okay.

Any help appreciated!!

 

[Pistachio]

Did you check their resistances?

 

[Codfather]

Did indeed. Circa 15 ohms for the MM and around 13 for the black one. Bigger concern really is that if it's just some random injector from another engine it could have a completely different (lower) flow rate meaning that cylinder isn't getting enough fuel.

 

[Amos91]

Never seen that injector before so I'd say change.

 

[green]

Not completely sure but it’s similar to a Clio 197/ 200 injector

 

[bloke]

wrong injector, bin it and hope no damage has been done, check oil level and give it a sniff to see if it smells of fuel.

 

[R3k1355]

Unless the other injectors are relatively new I'd bin the lot, plugs as well.

 

[Codfather]

Forgot to update; replaced the injector with a new one and built back up.

Started running even worse than before - constant heavy misfire. Got angry, stomped off and left it for a few days.
Went back and started re-checking everything. After running it a few times one of the plugs which I'd cleaned was still sparkling.
Checked the injector on this one and some numpty had forgotten to check the electrical connector on it with this plugged back in PROPERLY it runs sweet as a nut.

Would like to replace all of the injectors but sadly don't have the funds right now on top of all of the other mods needing doing.
Maybe a good job for the future though.

Cheers for the help guys and Happy New Year!!!