Recently I have been having missfire issues under boost. I took out my spark plugs and they were fouled so I put brand new ones in there that are gapped to .021, just like my old ones were. Now it doesn't missfire as bad but its still missfiring a little bit. its a Built D, Vitara Pistons, z6 head, 13PSI on a ebay t3/t4. its tuned and has been running fine for about a year. This problem only recently started happening. I also have an external MSD blaster coil. The spark plug wires are also fairly new with them being less than 2 years old and in perfect condition.

 

have you checked the dizzy rotor?, cap, ignition control module?

 

well the cap and rotor are about a year old, both MSD. And the ICM is brand new. I am thinking it has to do with a fukd up VTEC Oil pressure sender. Because when the sensor is working it seems to be fine. But as soon as the sensor starts acting up it starts again.

 

K well I fixed my vtec, and it's not that. The missfire/stumble is getting worse again. But it's not constant. The longer the car runs the worse it gets, but only under boost.

 

idk if its true but i've heard over and over that MSD products don't work well on Hondas. you may want to swich your cap and rotor back to OEM temporarily and see if the problem still exsists. if so, try runing without the MSD blaster coil. Honda engines are extremely tempermental when it comes to their ignition systems.

 

I was considering trying that, but I have been running that setup for a year now with no problems. In fact I was tuned with that MSD Blaster setup. I am just wondering now if possibly the coil is dieing and can't make a strong enough spark for it to jump under boost.

 

that may be possible as well. but i would assume the blaster coil would last longer than that. do you have upgraded spark plug wires as well? another option is maybe the wires are starting to get weak?

 

the wires are NGK replacements and were replaced about 12k ago. They are fine on both sides of their connectors, so I doubt its those.

 

sounds like a cap and rotor issue or coil dude diffently swap them out. and try them. even tho yours are only a yr old **** just can go bad. G/L man

 

ya im leaning more towards coil, because it gets worse the longer that I run the car without letting it fully cool down.

 

ah i see. yeah i would try using an OEM cap and rotor. if its true that MSD parts don't work well on Honda then this would make perfect sense. you can probably get away with keeping the blaster coil. but I've heard bad things about using both aftermarket and other non Honda replacements when it comes to cap and rotor. my engine is 23yrs old and has over 280K miles so I never use anything other than OEM Honda so personally i couldn't tell you.

 

well I cant keep the blaster coil without the MSD cap. And like I said its not like I just installed this and it happened. Its been like this for over a year now. The blaster is so that the spark is stronger and doesn't have issues jumping gap under boost. I will take the cap off later today, but considering that the problem is intermittent and gets worse the longer I run the car, and if I accelerate it, it gets progressively worse per gear, I am leaning towards the coil. But im debating on whether or not I should buy a new blaster and see if it fixes the problem. Because I dont really want to convert my dizzy back to internal coil. After I cut the terminals, and soldered wires for the external coil.

 

i had this same problem
i took off the oem cap and coil
msd cap and coil went on and it was like butter.
you sure did gap those plugs real low but that is of course a dif build then mine.
is your A/F ratio consistent as temps rise?

 

well they have to have a low gap for boost. That is the gap that my tuner told me to run, and its a pretty standard gap for turbo cars. I am not sure about my A/F ratio because I don't have a wideband. My ECU takes care of the A/F ratios and if it goes out of spec it will cut ignition. Its not pinging though, its just missfiring.

 

ohm check the coils msd should have some specs

 

the blaster has basically the same spec as the OEM, but with higher outputs. If thats what you were trying to say.

 

misfiring at high rpms?
higher the gap the better for turbo cars.
i ran a .030-29.
i remember when we were tuning my car and it was acting up and we gapped some new plugs even more to .030 from like .022 or sumthing and it was better.
then we had the other problem which the cap and coil fixed....
try a more of a gapped plug and see if it helps....if it doesnt just go back to your other ones but its an easy fix if thats what it is.

 

I seriously doubt its the gap. Thats the gap I have been running for a year already. that is why I posted here, because nothing has changed, its a year later and now it has this problem. Higher gap is not better for turbo cars. The STD gap is .045 or .040 depending on the engine. Race plugs from NGK, specifically ones for turbo race cars have a .010 gap or a .005 gap. Its like that for a reason. because the higher compression in the chamber creates increased resistance. Causing the spark to not jump gap.

 

are you gonna be able to try with a new coil? im pretty sure that will solve your problems

 

See if you can't find another dizzy and try that just to eliminate any distributor-related problems. If the misfire ceases, you know where your issue lies.

 

Yes I think I will go to Advance later today and buy a new Blaster SS. Because I found out that they actually sell them, at prices cheaper than ebay no less.

Well my dizzy is Frankenstein. Its a OBD-1 Z6 dizzy, with a OBD-2 Y8 Interface so that it plugs into a OBD2 harness. So no dizzy actually fits in the car. :/

 

Yikes...nothing like modifying Hondas lol. My car is hardly able to be serviced at an Acura dealership after all the crap i've done to it...i feel your pain on that one. Good luck with the coil swap

 

thanks lol

 

I hope this thread isn't dead.... I am running a stock B16 on 12psi.... when tuning we ran into the problem and solved it by installing a set of NGK wires, it was fine for a month or two and then the problem came back. The ignition was stock so as advised by SlowMotion (they tuned my car) I replaced the ignition coil(msd), cap(msd), rotor(msd), and plugs(ngk gapped at 0.21ish), car ran great for a day and then it came back... I'd love to find the solution to this issue, its driving me crazy!!

Thanks to anyone who has words of wisdom

 

I already fixed it. it was a loose wire/contact on my ICM.