hey this is my first post and i really need help!

heres the story every since i got the car it has sounded cammy like it is loping at idle.
a buddy thats a mechanic said dont worry about it but today i got the p0300 misfire code. no problems driving but you can definetly hear and see the misifire on the tacometer gauge.

injen intake (filter rather dirty but i vacummed it out two days ago and can see throw the holes fine in light)
borla exhaust
stock engine

recently replaced plugs, clean tb, replaced vacuum hoses on bypass valve and solenoid
As it wasnt running full boost before but now it is working. Not sure what the problem is but also if im idling my boost gauge sits at -40 ish kpa then if i lightly hit the gas it doesnt raise up it will go down to -80 kpa and stick there... maybe a sign of vacuum leak im not a mechanic... YET. Lol
Also there is a ticking noise at idle sometimes goes away and never hear it reving up a bit it will go away my buddy said need the valves adjusted probly but it can wait till the winter.
any help is appreciated im sick of my car doing wierd **** i wanna get it mint over the winter and start building it.

 

The ticking you hear at startup could just be an exhaust leak. Mine makes a ticking noise when cold and I am pretty sure that is what it is.

Now to your real problem. You say "you can definitely hear and see the misifire on the tachometer gauge" Does it sound like a single cylinder is misfiring? That makes a sound like a Subaru if you rev it up while missing on a cylinder. Does it only misfire at idle or does it misfire under load? When you go WOT do you get a flashing check engine light? How does it feel under power?

Misfires can have MANY different potential causes. Are you setting any OTHER codes along with the misfire code? Have you checked compression?

 

i dont have the tools to check for compression etc. As soon as i rev it up i cant hear it anymore. WOT sometimes it used to hesitate and not build full boost until around 5,000rpm. It would be stick at 60kpa until then it would break through to 80kpa and put u back in ur seat. I dont know the difference in sound between single cylinder and jumping etc. But its only noticable at idle but the light stays on. Only other code is for coolant fan relay so not related.
Found out my sc coolant was pretty well dry so i added it up today and its building boost better but this code came on once i finished filling. Probably not related but thought id add

 

how are you pulling the codes? does whatever you are using have live data? if so you can go to the misfire screen and see the misfire counter and see what cylinders are the worst and go from there.

 

just using my buddys $100 scanner. It has a little bit if data but i never recorded it idk what it means

 

It should have access to live data. On my scanner it is called the Mode$06 screen.

 

I will go scan it again and post all the results i can get! Also kind of think might be injectors or fuel pump or filter when i first picked up the car it was blowing a lot of sutty black smoke (unburnt fuel) i used injector cleaner and it barely ever does it now but also kinda feel a very slight difference with performance on a full tank oppose to half and below

 

Anyideas? Help please anyone that can

 

I just read one of your previous comments where you said the SC coolant was low and you added. It should not be low unless you have either an internal or external leak. But we have had someone experience that lately and if your laminova cores are leaking it tends to cause problems right when the user went WOT, not at idle like yours. But also if your IC system is dry it will severely limit your power under boost because your IAT2 temps will be through the roof. But that shouldn't cause misfire at idle either.

Basically we need more information to narrow it down or we'll throw so many possibilities at you it won't do any good. Essentially misfires come down to fuel, air, spark, and compression. You could be lacking any one of those for any number of reasons. The way to narrow it down is to eliminate possibilities. If you suspect your fuel system then the first thing you should do is check fuel pressure. However if you had fuel starvation issues I would think you would notice the problems more under higher throttle than at idle. If your misfire was prominently on one cylinder only it could be an injector issue as far as fuel goes.

What I would do is let your car sit there and run for a while then shut it off and pull your spark plugs and compare them. Just the appearance of the tip can tell you a lot. But as of right now the only information we have is that you are having a misfire. So you need to do some investigating and try to narrow down what it isn't. Until then we are chasing our tails.

 

My phone sucks for pictures but here are my old plugs that i pulled about 1000km ago and switch to ngk iridum 7s i believe...

it looks like a decent amount of sut and carbon buildup around the edges but the hook look kinda lean, dry and gray. Ill try to get a better picture on another phone

just today did a 2nd gear pull and at WOT had full boost then hit 5,000rpm and it just caved so i shifted as quick as possible... dont think its related but thats another problem on top of this now holy

 

Well you're only running two spark plugs so there is your problem

But seriously for your boost problem like you said was low on coolant so I would make sure your pump is even flowing. Check IAT2 temps. If your intercooler system isn't working correctly your car will pull most the power when you go into boost.

 

Having low fluid or a non functioning pump will not make your car misfire. There are plenty of lsjs running around out there with non functioning pumps and the owners dont even know. It also is normal for the system to lose a bit of fluid in stock form. You have no overflow tank, just a hose that aims down at the top of the filler neck. The way to fix this is option b.

 

The main problem is this misfire and surging. How do i check IAT2 ? The pump seems to be flowing bc i will fill the nevk and it will empty and bubble will raise and i see movement at the bottom of the t. The only reason i thought the boost problem could be related to the misfire is with a vacuum leak.

Just wondering if anyone had this problem. Basically at a red light it will be misfiring then out of nowhere start surging like 1500rpm-400rpm and sometimes stalls.

 

Yeah I wasn't telling him to check this because of misfires but for being down on power.

 

Can you get a video at least?

 

Yea I know. Just wanted to make sure he was clear.

What we really need is for you (OP) to put in some wrench time, so we can narrow down the problems. A compression test is a good start. You can buy it at any parts store for around $30. It is a tool that any garage should have anyways, so it won't be a waste.

You can also spray some carb/throttle body cleaner around the intake manifold to see if you have any vacuum leaks.

If you can get your hands back on your buddy's scanner and get some live data, that would be beneficial.

 

I would think it would have to be a pretty big vacuum leak to cause misfires at idle. Not sure though. Vacuum leaks could definitely cause the rpm fluctuation at idle. But like double clutch said. We need more information or you to narrow it down the things that AREN'T causing it like checking the compression.