Spark issue

[DylanArmstrong]

hey i just had a couple quick questions hopefully i can get some feedback from you guys.

My car had misfired a couple times under load in like 3 or 4 gear a few times a couple weeks ago, not everytime did it happen which made it confusing. I had a couple extra coilpacks laying around so i took them all out and replaced all my plugs and gapped them too .8-.9 and weirdly enough my old iridiums were gapped much smaller. anyways i havent put it under load since cause i still have too insure it but when i rev my car at idle up too about 4-4500 rpm like quickly it will do the same misfire sound as coilpacks would make, this seems new too me but could the plugs gap be doing this? By the way all my plugs seemed too be burning fuel about the same and they were a little on the rich side but thats all.

Any ideas?

Thanks

[jinglebell17]

my 1991 gts-t kind of does the same thing. i just changed my plugs from NGK copper core -BPR7E- to NGK Iridium -BCPR6EIX11- tonight (i dont even know if those are the right plugs to put in either.... ). i just finished putting them in about 20 minutes ago, upon start up my car blew some grey smoke from the exhaust, and then darker smoke (almost black) for about 20 seconds. then i took it for a quick burn around the neighborhood and it seems to run better but mine still sounds like it misses about every 15 seconds only at idle.. im pretty certain i need a throttle position sensor and a timing belt (among a few other things) but i was under the impression that my little misfires were from the coils or spark plugs too. my coils are next to new and my spark plugs are brand new now. once i get my throttle position sensor ill let you know what happens. also i havent had a timing belt done in 90,000km so im gonna try that after the TPS.

our cars might have the same issue

[Ghost]

Are either of you running a BoV? Or do you still have stock recirulaion valves? If your misfiring every so often, and have a BoV, this is not uncommon and has nothing to do with your plugs.

Mr. Armstrong, no. revving at zero load will not show any misfiring unless your plugs are REALLY REALLY bad (Fouled or melted) or your coil packs are fried and trust me they have to be really bad. You will have to road test to see if the new plugs made a difference. And which did you gap to? .8 or .9. If gaps too big you'll blow out the spark but thats a high boost and RPM under load. Id suspect the gap could have been the issue, but one way to find out is take her for a spin around the block. Also, if you got the wrong plugs, they could be too short and not contacting the coilpacks properly. Just a few off the top of my head.

Mr/Ms Jinglebell... the copper cores were fine to use as well as the new ones you put in. Personally i prefer copper cores. TPS will not cause misfiring. And if it's not working your RPM's would be all over the place. If it's off (say at a .45) it'll screw with your RPM's. There's a DYI on how to check and adjust it stickied somewhere on this site. White smoke bad (Lean or burning oil or turbos about to die), grey to black smoke good (Rich, blowing carbon.. which is way better than the latter 3 by far).

If you guys want another way to troubleshoot. Check for an ECU code. Also a DYI on this site on how to preform this. Is pretty simple.

[Skym]

Sounds like the gaps were too wide. Damaged 2x coilpacks on my car that way (combination of wrong sparkplugs and gaps). Lesson learned the hard way.

I've found from experience that sparkplugs can have 2x different length screw on tops in packet (open top). NGK are closed top tips and if correct for engine, hp level (heat range) and gapped down, shouldn't be a problem.

[DylanArmstrong]

Ok, i took my car for a drive today. With the new iridiums it would misfire and have no power under load whatsoever and i know my old plugs gapped even shorter wouldve done the same because they did the same misfire at idle when reved. I haven't crossed coilpacks out yet but i have inspected them all and a few of them looked gross so i replaced them with very clean extra coilpacks i had laying around with clean tips and springs. Now i still havent checked resistance on them yet, (i will tomorrow) but the car idles fine so they somewhat work fine. I cleaned my maf. Replaced my fuel filter. So really its running just fine as long as im not under load which narrows it down somewhat.

A couple things too add though, it will build boost fine and still pull pretty good if i lightly throttle it. Its running very lean at idle and if i counter act it with my neo it still will try too run lean so somethings telling the ecu to run lean for whatever reason! BOV is not possible i have had an aftermarket bov for monthes and it never changed anything since day one, this problem has developed over the past month. Only thing that makes any sense too me is coilpacks so i will have too confirm resistance first and then Ignitor chip? But i have no idea if they can just half work or not, anyone know?

[jinglebell17]

Are either of you running a BoV? Or do you still have stock recirulaion valves? If your misfiring every so often, and have a BoV, this is not uncommon and has nothing to do with your plugs.

Mr/Ms Jinglebell... the copper cores were fine to use as well as the new ones you put in. Personally i prefer copper cores. TPS will not cause misfiring. And if it's not working your RPM's would be all over the place. If it's off (say at a .45) it'll screw with your RPM's. There's a DYI on how to check and adjust it stickied somewhere on this site. White smoke bad (Lean or burning oil or turbos about to die), grey to black smoke good (Rich, blowing carbon.. which is way better than the latter 3 by far).

I prefer Mr. Jinglebell I am running a Blitz BOV.. is that bad? also, i think mine might be burning oil a bit. it doesnt smell like it though, it smells like it runs a little rich. it has 190,000km. im gonna have a compression test done as soon as its safetied cause theres a huge hole in my wallet right now and im running out of time to go back for a re inspection.

is there a simple way to tell if your turbos gonna die? my car still pulls hard and my Apexi S-AFC is set at good points of boost for each RPM setting. (max boost is 11 psi at 7,000 RPM but ive never taken my car past 5,000 RPM yet)

[Ghost]

Ok, i took my car for a drive today. With the new iridiums it would misfire and have no power under load whatsoever

No power under load..? Or boost..?

Methinks you may have the shorter plugs as Skym mentioned. If no power under boost, you possibly are blowing your spark out. What are the part number of the plugs you bought?

Pull your O2 sensor and see if it damaged, dirty whatever. Could be part of the problem.

If it's not an air issue or plug issue... logic would put you to fuel delivery. Possibly a leaking injector or and injector stuck open or, in the case of being lean, plugged. Running you super rich and bogging you well before boost. Try some injector cleaner and let it cycle through a whole tank. If that doesn't work, pull your injectors and manually inspect them.

Mr. Jinglebell,
Running BoV isn't bad it's just your dumping excess fuel which normally would have been met with the air re-cirulated through your intake by your stock recirculation valve. You'll get a pop every so often because of this. Nothing harmful. You will run a little richer because of this.

If your burning oil you'll have white smoke in your exhaust under load (before boost). If your turbo's gonna die or is dead on ya you'll blow white smoke as well but it'll be regardless of load or boost. It's because usually the seals done and you have oil all through your exhaust. And/or there will be noise. Most likely a really high pitched whining, this means you have shaft play on a level where your probably going to break an exhaust wheel off. You will notice this sound, it does not sound anything like regular turbo spool. It will worry you.

What you want to be looking for is black puffs once you hit boost. This is simply carbon because of slightly richer air / fuel mix. That Apexi S-AFC, great thing to have btw.