[RyanGT]

Hey guys, sorry havent been around much. Mods in garage for the newbies. Nothing has been done to it.

Problem is my stang is misfiring bad, huge loss of power and wont idle to save its life. Idle jumps from 500 to 2.5k. It started on a hard rain, and went away randomly. I figured something got wet? Now it happened again and hasn't gone away. Datalogging the o2 looks funky and doesn't do its normal wave signal. And the STFT's stay at 1.0 then go to 1.25 and stay there. Wideband reads pig rich dipping into 11 and 10s at idle (normally 16-17). And that is if i keep it revved with foot.

In addition to being weird KB wont boost at all. Normally a quick rev will give ya boost. But nada. I then tried to move the bypass while cars on and nothing. Cut off vac and still couldn't move it! With car off it moves freely.

I have tried reloading tunes. And did an open loop tune also (which doesn't use o2 sensors) which was my initial thought. I checked all the wires/connectors and plug/injector wires to see if everything is connected. Additionally to the other datalog things i mentioned, MAF looks functional. Frps has solid pressure of 38-40 psi.

Anybody have ideas for me to try? It stumbles so hard i doubt its iac or something (if i attempt to drive it, started first time while at work). I can give more info if something didn't make sense, tried to hit everything so might be jumbled.

Also hood a cowl encase someone thought plug sockets got wet. So no direct water can drip on it. And its not a huge cowl.

[RyanGT]

Problem first happened Sunday. And stopped Sunday after a few cycles (went to 3 stores). And started again today Wednesday.

And no codes, or pending codes. Oil in supercharger is perfect (level and its new). Bypass/no boost could of been coincidence. But no idea.

And

[Shaun03GT]

Hey whatsup Ryan how you been man? Havent seen you on here in a long time.

Sucks with your problem, thats wierd. Did you look at your spark plugs or check your COPs for any cracks/corrosion? 10-11 AFR at idle is rich as hell.

[RyanGT]

Besides this problem been good and busy! Graduated last week, and in process of trying to switch jobs.

Havent checked the physical plugs yet, its dark and no garage tonight Thats probably next step. Sucks cause bank 2 has intake manifold blocking 2 or 3 plugs.

[RyanGT]

Wouldnt a plug misfire throw a code?

[Shaun03GT]

Nice man congrats. Im giving you reps just for finally posting again lol

Sometimes itll throw a code sometimes it wont. If I were you though, I would check all the plugs you can get to, to see signs of detonation or damage. Check the COP boots, make sure theres no corrosion/cracks.

Also this may be a long shot, but hows your fuel/air filter? MAF? A dirty MAF could cause that. Could spray it with electrical cleaner.

You dont have a Vacuum leak at the plenum do you?

[RyanGT]

Fuel filter is new, and large and in-charge! Its the -8an one from summit. Air filters gtg also.

I was thinking dirty maf too like you were saying actually. Since it first happened in a heavy rain (parts flooded) so could of saturated filter and got some water/oil on maf. Dunno

No vac leaks that large that i know of. When it idles its at normal vac pressure. It does bog when i rev it when it would normally hit a little boost.

[Shaun03GT]

It could be a dirty MAF, I would hose it down with some electrical cleaner, let it dry and try that. Then I would try the plugs/COPs. Hopefully someone else can help you more

[RyanGT]

Yeah it used to be prime time when i first posted it. Went for a quick 6 mile run come back and its already on second page

Any other ideas to check while im there? I figure ill let as many connectors as possible air out. And check a few plugs.

[Shaun03GT]

Id check for some vacuum leaks too...just to be safe I guess. Seems wierd though. I think its either a dirty MAF, or an issue with the plugs/COPs

[RyanGT]

Alright thanks man.

Very weird it runs completely normal, i shut it off to do a little cosmetic work. Then turn it back on to move it into my parking stall and it has this problem as soon as I turn it on.

[RyanGT]

for ideas

[1999cobra92]

Well my did misfire during the rain but it would come and go. But now it doesn't do it. I think it's cuz of the rain. Like today my car is running perfectly

[RyanGT]

When it started again it was from a car wash. Thing is that it drove home fine, i turned it off for 45 mins and turned it back on and the issue was back. If it was water you think it would of happened after the car wash?

[1999cobra92]

most likely yeah

[RyanGT]

Alright fellas. Now that it is morning i went to move car to garage (im in a condo complex). It is currently raining, but problem is now magically gone. Boost registers when i rev it. No funky idle...

But last night it wasnt raining and it wouldnt idle to save my life. So if i need to go somewhere it does this shit, but if im off it doesnt? wtf

Ideas on that! Problem magically fixing itself lol.

[Sally845]

hmm.. try cleaning all your electrical connections in the engine compartment with electric connector cleaner, and compressed air, then maybe throw some dielectric grease on the plugs too? i had a similar problem, and it was the actual plug for the MAF sensor, it got wet.

[RyanGT]

That is actually my suspicion. Since Maf rarely throws code even when giving troubles. All my connectors are clean but ill give em a once over. (i like to keep all that shit dialed in). And gonna check a few plugs too starting from the back.

[RyanGT]

Also my hood before i fixed it, tuesday go figure, had a gap on passenger side. Which could allow water to get in where the maf actually is.

[Sally845]

cool, keep us updated man, good luck