cgawelko

Alright so I have had this misfire going lately. Cylinders 3, 5 and 8 are not sparking at all. Bank 2 camshaft position sensor reads 1094ohms cold, which is in spec. Ignitiors, and coils both getting proper voltage. All fuses are find, and all the relays have the proper voltage where needed. I replaced the coil thinking it was the issue, and it isnt.

I get spark at the coil. at the cap. Everywhere EXCEPT the plugs. The plug wires have spark in them, if I put a screwdriver in the end of the wires, it will arc to the manifold. If I put the spark plug in it, it doesnt spark. If I put the spark plug in the wire and have it close to the manifold, it will arc to the manifold, but the spark plug flat out doesnt spark. Tried it with Iridium plugs, and double platinum plugs, both brand new.

I have a 4th set of plugs on the way, but i am sick of throwing money at this and not getting anywhere.

Anyone have any advice on the whole deal?

RA40

iTrader: (6)

That's the passenger side rotor-coil bank. Any arc trails inside the cap and or any odd marks on the rotor? I'm sure you've checked proper wiring, that's what comes to my mind when the coil and igniter are getting proper voltage. It is sparking because as the rotor turns the crossed wire is sending the spark out but in term of the engine it is mistimed.

Yamae

The arcing should travel more than a half inch in the air under 1atm. In other words, you need to set up the air gap that big when you check the sparking energy. The real arcing in the cylinder is occurred at the pressure more than 10atm. Higher the pressure, shorter the travel distance.

Have you checked the travelling distance?

Less than a half inch simply means that the spark energy is not enough. A bad ignition coil, a bad igniter, a bad distribution or leakages causes it.

There are many other issues related to the misfire but check a half inch spark first since you can do it quickly.

cgawelko

Caps and rotors are all new, wire set is new, and I replaced the coil for bank 2. If I switch the ignitors, the no spark doesnt move, so its after the ignitors, after the caps and rotors, and after the coils. And after the wires since they are new too.

The timing is advanced, but it was running just fine with the advanced timing before. Once I started tuning it on speed density I started having these issues. I got a few good runs in and was dialing it in and then when I went to leave the driveway and it dies out when I hit the gas pedal and has been down ever since.

dicer

If everything works up to where the spark plug, plugs in to the wire, then it must be some bad spark plugs.
If a spark plug is dropped by people at the parts stores or you or who ever. They then are junk. Maybe they may survive but small cracks can develop in the insulator.

cgawelko

Well I have a set of NGK 4554 on the way some -8's so they will take the extra heat from the high octane and extra timing and junk. We will see when they get here. If not working by then, I am going to sell all my performance parts and just put all the stock stuff back on and sell it as nonrunning. Because I have tried so much stuff and its just to the point where I dont care anymore

timmy0tool

iTrader: (7)

"been down ever since" meaning the car never started again? have you checked if you have fuel?

cgawelko

Thats right, not running since. Got PLENTY of fuel, **** I could hang a bucket from the tail pipe while cranking when it first started. Backed off the fuel on the tune and its doing better, but not running.

dicer

No extra heat from high octane, if there was it would ping and detonate more with its use. Its a misconception. High octane lowers the temp of combustion. Did tests years ago proving it.

So how did you back off the fuel? Excess fuel could also be the cold start valve leaking.

cgawelko

Lol I got two sets of burnt red plugs that will disagree. I'm sure 8000rpm isn't helping at all.

timmy0tool

iTrader: (7)

reason i ask for clarification bc being down doesn't necessarily mean the motor doesn't turn on. the motor turned on before, but was just misfiring and would not rev when the gas pedal was pushed. just to be clear, you are telling us it won't start at all, correct?

is the motor bone stock? sounds like you have mods installed. how's the condition of your AF sensor? what year is your car?

cgawelko

AFM sensor removed and tuned out, running speed density, injectors, intake, exhaust, and running high grade fuel. occasionally 112 but usually just nonethanol 93.

Timing was +16 idle and up in steps until 4500rpm its +30 and its at +30 until 8k which is the highest ive revved it on my logs at +30. I did end up having to replace the caps and rotors and stuff because the bank 2 rotor jumped the gear and messed up the cap, thats why they were new.

dicer

High heat or not high heat is caused by air to fuel ratio not octane.

cgawelko

Bueller? this is now 10 characters.