I replaced my crank sensor the other day in hopes the little bit of noise we saw on the oscilliscope was the cause of the misfire, but still no dice. Completely at a loss where to look next. Timing is dead on, trigger plate is dead on, tried pulling fuel, messing with injector scaling/latencies, VE table and no changes. Again, compression checked fine, no burnt valves, tested AND replaced cam, IACV, MAP and TPS sensors, tested/swapped coils, checked plugs/regapped at least 10x over etc... Wideband reads rich when it misfires, and when it's cold the car willnot idle unless I hold the throttle down to keep it from dying. Between 3-4k rpm's where the big breakup happens the car completely loses power like fuel cut almost but this happens off boost at light throttle only. When I apply more throttle and a heavier load the misfire goes away completely. No issues in boost at all, only at idle and part throttle operations... I've been trying to get Tom to send me my base map but isn't really responding to my e-mails either which makes it tough. If anyone has any suggestions please help me out, I'm dying to tune and drive my car but this misfire is killing me.

 

It'll be misfiring due to being too rich.

As you said...pig rich when driving.

Speed density tune........you NEED an exhaust before getting a datalog otherwise it's meaningless.
As for WHY it's too rich.........pretty much normal for a badly modded car.
But you haven't listed you mods.

 

Cam sensor starting to go? Although when mine went, the car was barely drivable.

 

My car is completely put together right now and as I said before it misfired before the exhaust was off. The wideband reads rich when it misfires, and it started happened out of the blue. Why assume it’s poorly modded?

 

Tested and swapped (to be sure) cam sensors with no change.

 

Because it's misfiring.

A misfire shows up as a lean spike , not rich.

So it's going too rich before it misfires......due to a bad tune or wrong mods or both.




You still haven't listed your mods.

 

Performance mods are as follows:

MAP Stage 2 2.3l 9.5:1
MAP stage 1 head w/ beehive springs
MAPerformance Rev 3 intake manifold
Full Blown 70mm throttle body
Gsc S2 cams
MAPerformance L19 headstuds
FP Zero turbo
MAPerformance long runner exhaust manifold
TSComptuned double pumper
FiTronic flex fuel kit
ETS fmic
FIC 2150cc injectors
AMS fuel rail
Aeromotive fpr
Custom MAPerformance uicp
Muse licp
STM speed density intake
STM FP SS housing downpipe
STM sealed catch can
Buschur Racing cat back w/ SD muffler
Total bov
Grimmspeed 3 port EBCS

Should be about it... I may have forgotten a few items but that’s the gist. It goes rich after the misfire or breakup not before which is part of what has caused this to be so hard to diagnose. After checking all the hardware I’ve been leaning towards a bad tune, but Tom has been extremely hard to get In touch with as of late so I haven’t been able t get a new base map to try.

 

You'd want to check the fuel pressure of course...........so you'll need a gauge.

 

you have a COP kit? bad coils? wondering why such a big plug gap. Might as well do a compression test just in case.

 

i noticed in video, SES light flashing when you were revving. not sure what that means.

 

There's always a slight time delay in getting an O2 reading.
What you should be looking for is the lean spike you get with the misfire.


Datalog required?
When idling like in the video.

 

Yes I have a COP kit, and I tested the coils and all checked out. I did a compression test and that checked out. My plug gap has been all over the place to see if it was a matter of plug gap causing my issue. SES light was flashing because I had my tactrix cable plugged in so that’s not a big deal either.

 

I want to say we watched fuel pressure but I can’t recall so I’m gonna do that again to be sure. I have a serial cable for my wideband now too so I just have to get that wired up and I can get some logs again but with air fuel this time.

 

edit: ignore me, I'm a dummy

 

I heard from Tom the other day and he’s confident my tune is causing my car to run like ****. I’m okay with that for now because I’m sick of tearing the same stuff down and putting it all back together lol I guess we’ll find out soon!