Rb20 Skyline Sounds Like A Wrx

[sama1500]

so my skyline is sounding like a wrx, ive already researched on the topic and ive so far replaced the coil packs with brand new yellow jacket ones and new spark plugs, when the car is cold started it sounds normal but after a few minutes of driving the sound appears, it used to appear and leave whilst driving but recently it doesnt leave at all and just continues until the car is turned off and on again, any suggestions??

[sama1500]

also a while back when replacing the injector seals i found out one of my injectors wasnt working 100% but didnt change it at the time, could this be a cause?

[GH05T]

yes + sparkplugs?

[sama1500]

put new ones in before changing coil packs, just ngk ones, didnt do a thing, and the plugs i took out were in decent condition anyway

[Ben C34]

also a while back when replacing the injector seals i found out one of my injectors wasnt working 100% but didnt change it at the time, could this be a cause?

Are you seriously asking that?

Yes. No shit an injector not working correctly will cause a misfire. What do you think it would do?

[sama1500]

well it worked absolutely fine for the next couple months so i didnt think much of it, im obviously asking a question because i dont know the answer you f**kwit.

[Ben C34]

well it worked absolutely fine for the next couple months so i didnt think much of it, im obviously asking a question because i dont know the answer you f**kwit.

Don't get upset.

You brought it up that an injector wasn't working correctly. Of course that will cause a misfire. Fix it. Or alternatively waste your time wondering what else could cause a misfire.

[sama1500]

im not getting upset, you were acting like a dick so i responded, from the research i did everyone said coils/plugs and since i had fixed both i was wondering what else would be the problem so i asked, i did plan on upgrading injectors anyway so its not like im going to leave it, cheapest (new) ones seem to be bosch and i'll probably go 440cc since i dont plan on running big power or anything but i do plan on getting some more power out of it.

[GH05T]

Ben, this is a forum for people to ask questions, not everybody me included know everything and find it hard to chase down issues. our engines do have common faults but these can be a miriad of things quite often. you do have a habit of beliteling people for asking.
if it frustrates you to be asked then just close the page.

I have had a similar fuel related issue which turned out to be dropping rail preasure from my pump but it did not result in dropping a cylinder but an injector may cause this. my issue for the wxr ayptom like everyone else was a coilpack problem which you have addressed. the next obvious place would be the injector if you know if dodgey but being a mechanical/electrical/fuel componant can bring with it all sorts of fun. it could come down to grounding. best thing is to do some more testing and narrowing down. the easiest way to be sure its not the issue is swap it out but yes this takes spending and possibly thorwing away some cash.

[Ben C34]

im not getting upset, you were acting like a dick so i responded, from the research i did everyone said coils/plugs and since i had fixed both i was wondering what else would be the problem so i asked, i did plan on upgrading injectors anyway so its not like im going to leave it, cheapest (new) ones seem to be bosch and i'll probably go 440cc since i dont plan on running big power or anything but i do plan on getting some more power out of it.

Ok here are more things that can cause a misfire, aside from the coils and plugs

Injectors

Injector loom

Coil pack loom

Various plugs (dirty, wet, not plugged in fully)

Ecu connection

Afm

Vacuum leak

Boost leak

Damaged valve

Blown head gasket

Low compression

Damaged piston

Fault cas

Incorrect timing

Fuel pump

Fuel pressure

Wrong injectors

Etc

So as you can see sorting out the injector issue you have noticed is the sensible first step.

What ecu do you have?

Do you realise you will need and tune for the car to run with those injectors?

[GH05T]

agreed

[sama1500]

stock ecu and yes i know that, spoken to tuners and i had already planned on getting injectors, fuel pump and dump pipe (mines standard but the rest of the exhaust is 3") and putting the boost up to 14psi with a nistune

[sama1500]

would putting it on the dyno be a faster way of diagnosing the problem? while talking to the tuners they said its $100 for an hour of dyno time so im thinking of just doing that to diagnose the problem to save the headache of narrowing down the problem and possibly wasting money replacing things which dont need to be replaced

[Ben C34]

I don't think so.

If you are planning on getting the bigger injectors and a tune just do that.

An easy way is to pul the plug on an injector with the car running. If it gets worse that injector is probably ok. If it stays the same that injector isn't working. Same with coils, but they tend to not cause issues at idle untill they are totally rooted.