Help, Rb26 Sounds Like A Wrx

[autechwgn]

Hi guys and girls, anyone have any ideas what could be causing my stagea to run rough? Sounds like it's running on 5 but tacho says it idles steady, it still makes boost but slowly, feels like it goes good once the boost kicks in. Just changed the plugs and coilpacks and all the plugs look the same, no fouling etc. Wondering if it could be fuel filter or boost leak or afms, or fpr? Just had fuel pump done too. Also has a bit of backfire on gear changes

[R.3.2.G.T.R]

one of your coilpack plugs is not connected correctly, unplug and plug till it makes a click

[autechwgn]

It was doing this before I changed the packs and plugs, could it be my harness?

[GTSBoy]

Yup. A pin might have pushed back out of a plug, or you might have broken a wire (they do get old and brittle from living in such nasty hot conditions for so many years).

[Ben C34]

Just because the tacho is stable doesn't rule out a cylinder missing. With car running disconnect one coil pack at a time, in no time you will know which pack/plug/part of loom is dodgy

[autechwgn]

Ok guys, replaced the plugs, replaced the packs with splitfires and just put in a new coilpack loom, still sounds like it's missing and smells rich plus is very laggy and won't make full boost, could it be an injector?

[GTSBoy]

Well, yeah, it could be an injector. Could also be a hole in a piston, broken ring, burnt valve.......Internet diagnosis is a mug's game.

[autechwgn]

Shit Shit, I hope not.

[Ben C34]

Just because the tacho is stable doesn't rule out a cylinder missing. With car running disconnect one coil pack at a time, in no time you will know which pack/plug/part of loom is dodgy

Did you do this? Or just replaced stuff for fun? Narrowing it down to a cylinder would have helped you determine if it was a coil pretty easily.

[autechwgn]

I replaced things that seem to cause common problems so I don't have to worry about it again for a while. It used to come and go so I had ruled out mechanical problems as I would think damaged piston or cylinder would be more permanent.

[scotty nm35]

If it is intermittent there is a good chance one or both of the AFM's needs re-soldering, there is a 'how to' around on fixing them if you do a search.

It could be an injector too, would be a good idea to get them cleaned and flow tested just to rule them out.

[autechwgn]

Thanks mate, I'll check the afm next and get the injectors cleaned.

[GTSBoy]

I would think damaged piston or cylinder would be more permanent.

I was just pointing out that trying to diagnose such problems over the net is near futile. It always turns out to be something either very obvious or nothing that anyone thought of.

[Ben C34]

I was just pointing out that trying to diagnose such problems over the net is near futile. It always turns out to be something either very obvious or nothing that anyone thought of.

So tempted to put that in my signature.

[Blackkers]

dumb question but have you checked compression? it could quickly rule out something sinister

[autechwgn]

When I bought it they did a compression test and has only done about 5000k since then so no I haven't plus cause it was come and go I didn't think it could be that. Happened around when the alarm went in, imobiliser issue maybe?

[Even_Flow]

Wouldn't surprise me if its an afm.

Another quick thing to do would be check over all of the I/C piping and joiners for a leak and vacuum lines too

Edited November 14, 2013 by Even_Flow

[Rolls]

Pull injector plugs one by one until one doesn't make it any worse than it is already. Once you find the cylinder that is missing check the plugs/coils/loom for that cylinder.

Could even use a screwdriver to the ear to find which one is missing.

[autechwgn]

I already replaced all those but I have it booked in at proximity motorsport here in mackay next Thursday. Hopefully it's nothing serious

[Rolls]

Sometimes that is the best option, they have the tools to figure out what the issue is, end up spending more if you just replace everything trying to figure out what is wrong.