High RPM misfire...

[innocenttalon]

Yup I searched but could'nt really find anything similar to my issue. My car seems to misfire at high rpm, can,t go past 7k. The wierd thing is, it only happens in third gear, 1st and 2nd cant go as high as 7.5k without a problem(I haven't tried doing it in 4th or 5th gear). I've already change the plugs and gap them properly. I also have newer plug wires on,but they are only stock replacement. This is on a HX35 @ 30 psi, with alcohol injection, if that matters.

 

[dsm4lif3]

On my first car I had almost same problem. I hated it never found what it was before I sold it. I replaced plugs,wires,02 sensor and had timing don't and other stupid misc shit never fixed it I hated it. Sorry I couldn't help just telling u my situation an what I did and didn't help. Check timing and what not could be a possibility.

 

[sniver]

Is your profile up to date? I bet not since it says an 18g with 560's. hx-35 is the new setup, what fuel pump, and what injectors are you running? It says you have ecmlink, do you have a log?

Has this happened since a change,or has it been like it forever? Does it like feel like it hits rev limiter in 3rd early, or is it breaking up?

 

[innocenttalon]

Sorry my profile isnt updated. I do have a log, I'll post when I get my laptop back. As for fuel, I have rewired walbro 255, and 1200cc injectors, so I'm guessing lack of fuel isnt the problem. This actually happened when I started using alcohol injection. I also thought it would be running too rich, so I leaned out a bit till my WB was logging ~11.0-10.6. It feels more like its breaking out, preventing me to get any higher than 7k.

 

[BigBeans]

Spark blowout?

What are your plugs gapped at?

 

[innocenttalon]

They are NGK bpr8es, gapped at .22, any wider and I bog/breakout at even lower rpms.

 

[BigBeans]

They are NGK bpr8es, gapped at .22, any wider and I bog/breakout at even lower rpms.

So are you saying this problem gets worse with wider gaps, and better with narrow gaps?

If so it's just blowout.

Either your coils/wires are tired, or the water/alchy added to the mix has just made the charge too thick for the stock ignition and it's time to upgrade.

 

[innocenttalon]

So are you saying this problem gets worse with wider gaps, and better with narrow gaps?

If so it's just blowout.

Either your coils/wires are tired, or the water/alchy added to the mix has just made the charge too thick for the stock ignition and it's time to upgrade.

I havent tried narrower gaps yet, and yes when I was at 26-28, I would breakout as soon as I hit boost. I just kept going narrower to 22 till it did'nt break out anymore. I guess your right about the charge being to thick. Is it any danger going as narrow as lets say, .16-.18? I might try that first then I upgrade to thicker wires.

 

[Absit]

I'm liking weak spark for this as well.

 

[sniver]

At some point you'll start having issues igniting the mix just due to the arc size. You could try it at like 18 just to verify, but I am not sure about the long term effects.

Are you using quality wires? Do you have a different coilpack you could try?

alky supresses knock, makes it harder to ignite erraticlly, and at the same time it makes it a bit harder to ignite on purpose. In my mind, you were on the verge of your coils limit, and the alky made it a hair harder to ignite,and now it presents itself as a miss up top.

Sent from my Droid

 

[xiteamxi]

my only though would be spark blow out. dif coil pack cant hurt

 

[innocenttalon]

At some point you'll start having issues igniting the mix just due to the arc size. You could try it at like 18 just to verify, but I am not sure about the long term effects.

Are you using quality wires? Do you have a different coilpack you could try?

alky supresses knock, makes it harder to ignite erraticlly, and at the same time it makes it a bit harder to ignite on purpose. In my mind, you were on the verge of your coils limit, and the alky made it a hair harder to ignite,and now it presents itself as a miss up top.

Sent from my Droid

I still have the stock coil in the car, as for the wires Im using replacement Denso 7mm. Could it be that my coil is going or my wires are too weak? or both? Either way Im gonna change the wires to some thicker ones, I will have to find aother coil if that doesnt fix it.

 

[sniver]

I imagine its the coils. I was getting at if you have autocrap replacement ones that have to much resistance, damaged stockers, or ect. Bigger wires could help if their resistance is less, but honestly I've never heard any actual proof whether or not they make a difference

 

[innocenttalon]

I imagine its the coils. I was getting at if you have autocrap replacement ones that have to much resistance, damaged stockers, or ect. Bigger wires could help if their resistance is less, but honestly I've never heard any actual proof whether or not they make a difference

Okay, thanks for the help. I never got sh!t done to the car today, I'll try new coils from a friend and smaller gap, will let you guys know what happens.

 

[jed344]

my car does same this past 6k usually i have 255 ffwd fuel system stock injectors i replaced plugs. gaped um to .028 new wires tried stock coil packs and new ones. i just never figured it out myself