Missing at WOT

[Casper86]

my car has had a problem missing when at WOT. I get a PFFFF code and Misfire on Cyl 2 on my AP. When the AP is monitoring data and it misfires , the AP reports losing comm. with the ECU.

I was thinking I have a bad plug (30,000mi on current set). However when I switch from my performance maps (custom Tim Bailey protunes) to the COBB economy map it never misfires when WOT.

I am now thinking its the injector on cyl #2. thinking maybe it can keep up with the pulse width of performance maps.

Thoughts? advice? please, and thank you!

 

[Casper86]

the car already has one step colder plugs, the car ran great all last summer but this spring when I brought it out of hibernation (it stays garaged during the winter) it started having the issue.

the tunes where made by Tim bailey of surgeline tuning 3 years ago and nothing has been changed on it.

so I dont think its the tune. I was thinking about swapping injectors to see if the misfire changes to a different cyl.
I am planning on replacing plugs soon, but would a tune/ throttle load really be an issue with a plug?? wouldn't a bad plug misfire at WOT regaurdless of tune??

 

[Casper86]

I Dont know , can gapping magically change when the car sits for a few months ??
LIKE I SAID: the car was running like a stallion when I put it away for winter (was still started/brought up to temp 1x a month) when I started driving it again in the spring it misfires at WOT 80% of the time. Nothing on the car was changed/ replaced except oil in that time period.

why would it misfire on a performance map and never on an econ map if it were a gapping issue ??? enlighten me

 

[Casper86]

LOL! I have yet to be enlightened , maybe Ill ring up modified by KC and ask for their advice.

 

[joey.lisano]

Step 1: Be grateful when people take time out of their busy day to help you with your problem.

Step 2: Buy new spark plugs, gap them, and install them.

Step 3: Reset ECU and go for a test drive.

You've been going WOT on a protune for 3 years with 30k on the spark plugs. My guess is that it's the spark plugs and has nothing to do with the winter hiatus.

 

[Casper86]

I will reconsider my tone , and I apologize.

I was just trying to figure out the reason why defined (jordan i assume) would think it would be a gapping issue?. When the car was stored it never had the problem. it was started and brought up to operating oil temp once a month during storage, I added Stabil to the tank. It seems like as soon as I brought it out of storage it has been having this problem. The tune was made @ approx 75 deg and 60% humidity. It has occured in all types of weather/ temp.

I am replacing the plugs never the less, I guess tomarrow I will swap injectors , do a few pulls and see if the misfire follows the injector.

thanks for the advice and I will try to refrain from anymore drama

 

[Casper86]

Thanks for your Input defined.

 

[IGOTASTi]

I will reconsider my tone , and I apologize.

I was just trying to figure out the reason why defined (jordan i assume) would think it would be a gapping issue?. When the car was stored it never had the problem. it was started and brought up to operating oil temp once a month during storage, I added Stabil to the tank. It seems like as soon as I brought it out of storage it has been having this problem. The tune was made @ approx 75 deg and 60% humidity. It has occured in all types of weather/ temp.

I am replacing the plugs never the less, I guess tomarrow I will swap injectors , do a few pulls and see if the misfire follows the injector.

thanks for the advice and I will try to refrain from anymore drama

Thank you very much. You will find out we do play games and have fun in off topic, but the mods and people on this forum know their stuff and left other forums cause of drama. I thank you for your support and glad you are here.

 

[HolyCrapItsFast]

You might also want to throw some injector cleaner in the tank. It is possible that suspended sediment has slowly cloged your injectors during it's hibernation.

If the plugs are not gapped properly... say to big... at WOT the added fuel and boost can blow out the spark. Adversly if it is to small there won't be enough exposed spark to ignite the extra fuel. Also I have seen plugs foul from just sitting over the winter due to moisture buildup in the cylinder. I see this condition mostly in marine applications, though I suppose it is possible on cars as well. With an improperly gapped plug any kind of fouling will also have a greater adverse effect than if the plug was gapped correctly. On the Econ tune you don't see these aggressive conditions so it may not show up until you light it up with a more aggressive tune.

 

[Casper86]

Makes sense holycrapitsfast, thank you for your input/ ideas!!

I forgot to take in the fact that possible build up or wear on the electrode could change gapping technically, plus the point you made- the performance map delivers more fuel which could blow out the spark before ignition occurs.

great input , thanks !

 

[Bluedemon_II]

Check for broken injector wires or coil pack wires. You could have had a mice chew up some wires and that could lead to electrical problems that could present when you demand the most out of your engine. Happened to me.

Buy a feeler gauge and see where the gap is at. Don't use that coin type gauge since it is most likely to damage your iridium electrode. Do you have an appv2? You could log Knock correction and see if the Ecu is registering that misfire as knock. If so you could have some issues at hand. Clean your Maf sensor if you are using an oiled filter. Your maf could be dirty and in need of a cleaning.

 

[Casper86]

thanks bluedemon, I have have a AP V2, I have run data logs and no knock/ values were present, I also monitored cyc2 roughness and got nothing abnormal.

I have also added 32 oz oftorco (race fuel concetrate) to 93 oct, which is supposed to = 105 oct (per tim bailey's recommendation) and ran the 91 oct stage two map he created for me, and it still misfired.

I thinking/hoping its a ignition/ fuel delivery problem

 

[Casper86]

mod list is in my journal, I use QT 91 which has 10% ethanol for my 91oct protune map. I use BP 93+32oz of Torco race fuel concentrate to run my highest performance protune map. Tim bailey said It would be fine to run 91+torco on that map, so I use 93 just for good measure.

For how much of a PITA it is to get to/ remove the spark plugs, its worth the $60 to just replace them. I don't have the coin type gap feeler , I have a set of the strips.
again , thanks for the ideas guys!