Running into an issue with my car missing up top between 6-9k at WOT, and has a better chance of happening when I down shift before a pull. The car misses continuly through the pull, kind of feels like when riding a bike and the chain skips a tooth on the sprocket. I can hear popping out the exhaust as it misses but not the sound of a backfire, no flames or anything like that either. I just installed a wideband after installing idle afr was wild from 14.0-17.8 back and forth 14-16 cruising and 10.1 a WOT.

Brought the car in for a retune telling them about it and was told plugs were probably to wide of a gap .024 and said they go down to .020 for the power range. Fast forward to today, got the car idle afr still wacky, cruising afr was more focused around 14.5 but would drop to 17.8 and go up to 13.0, WOT afr was 11.2 solid every pull, yet still up top I was missing as before the re-tune.

I'm letting the motor cool down and I'm gunna check the gap just to double check but I really don't think it's that. They closed once I was home so I'll be calling Monday to see what they say in the meantime all input is helpful.

Bpr8es
Kelford 272/super tech spring locks,
Ets 3in FM w/ full piping
1200cc fic's warlbro 255
Grimspeed 3 port
73 hta green 84mm cover 18 psi wg 27 psi
Car makes 410/378 but when I went back for re-tune was exspecting a full pull on the dyno graph but only 3 pulls were made up to 6k and was told car makes same full power as last dyno session about a year ago

 

Why are you revving to 9k anyways? That seems pretty high I wouldn't shift past 7k unless the tune allows you to go past. It could be bad spark plugs because I had a similar issue. Swapped plugs and it fine

 

Plugs have been swapped twice, I'm on fresh plugs swapped before tune and while they tuned it. And 9k rev because why not? No reason to spend all the money not to go fast

 

Quote of the month...

 

What plug wires you have on the car? Or what kind of ignition coil?. Sound like you have a spark issues. But not the plugs

 

9k on a stock block is a no go. A green isnt even flowing close to 9k. So not only are you hurting the car more than likely but your way out of your powerband.

 

Okay thanks

 

Spoolin up cop about a year or two old, was the new no re-manufactured one

 

Yeah the green if way out of it's range by that rpm range.

 

Would see if it happens on stock coils if you still have them

 

Go get you a set of NGK (red box) dont go past factory gap .22-.25 and you will be good. I also have the nonHTA green with no issues with those. I also would agree with the other guys about the 9k rev due to the fact the green has great spool not like other laggy turbos, but up top it kinda falls off.

 

^^^^^if your running over 15 pounds of boost gap no more than 24 I run 23psi and had that problem and checked gap and set 22 and has run fine. Also hitting 9k may be hitting rev limiter.

 

9k just a limits or a margin of rpms I gave to better diagnosis problem as it was only happening up top.

Tuner did not replace or re gap the plugs before 'retuning' even though one of the main problems was the missing up top. One of the coils in the CF spoolin up cut out was also loose I re gapped at.22 tightened the loose coil and it's no longer breaking up.

Now to the new problem is did the guy even tune my car. AFR are still outa wack. They didn't touch the plugs and didn't even notice the one coil that was loose. Almost don't wana call the shop back to set up an appointment and just take the car elsewhere

 

Regardless if 9K is just a limit or margin of rpm in your words, on a stock rod your gonna have a much bigger problem than a tune if you keep revving that high. Your gonna have a Big @$$ hole in the block. I would not recommend revving the stock block stock internals past 8k.

Also as far as the AF are you watching it while holding the throttle steady while cruising, if you let off the gas its gonna gonna dip then come back to around 14.7-15.2

 

yeah, i wouldn't even go higher than the 7.5k rpm. with cams and my 1200cc's my cruise is up and down between 14.5 and 15.5 or so. do like he said above and drive with it cruising with your foot on the gas steady. but really, watch your wot shift rpms or else you will need a new block.