very high idle after nitrous backfire

shorty · Sep 3, 2013

raced last night, raped up the rpms a little to high had a nitrous backfire
Now the car idles at like 3500-4k
but if i unplug the MAF, it idles down. sounds like shit but it does idle down.
im thinking it blew the MAF

Musturd · Sep 3, 2013

There's a good chance you blew the maf ... Are you running a window switch or are you a crazy mofo like me , I power shifted on the bottle all Saturday night with no window switch like a asshole ... A friends 08 gt was having issues similar to what ur saying, happened like 3 runs in a row the other night it's a auto though. It actually destroyed the cone filter

ttocs · Sep 3, 2013

Sure there isn't an air leak somewhere in the intake now?

shorty · Sep 3, 2013

wth, i just posted a big reply

Yea i run a window swtich, i have some big balls but not big enough to not have some type of safety on a 240k mile stock motor and a 125 hit lol
as far as a leak in the intake, i would think that even when the MAF is unplugged the vacume would still cause a high idle? could be wrong on that

ttocs · Sep 3, 2013

If your getting un-metered air in after the maf it will cause it to idle high.

shorty · Sep 3, 2013

its possible. im going to throw a buddys MAF in after work today and see what it does, if it still idles high, then off comes then intake

shorty · Sep 5, 2013

replaced MAF and IAC no change. i decided to drive it and see how it acts. and omg does it miss

MustangChris · Sep 5, 2013

you inspected the plugs yet?

whats your car, again? Things could be a bit different from the 5.0s to the 4.6s... for example, you may have cracked the plastic intake manifold on the 4.6; or you could have some kind of leak between the intakes on the 5.0....

Orange 94 · Sep 5, 2013

Hit it with another shot of nitrous. Should solve things...

MustangChris · Sep 5, 2013

Orange 94 said:
Hit it with another shot of nitrous. Should solve things...

bahahhaha.

gunna hit yours with more boost?

Orange 94 · Sep 5, 2013

MustangChris said:
bahahhaha.

gunna hit yours with more boost?

BBBBBBBBBBBBBBBBBBBBOOOOOOOOOOOOOOOOOOOOOOSSSSSSSSSSSSSSSSSSSSSSTTTTTTTTTTTTTTTTTTT!

Actually I have a miss in mine now... I think its ignition, but we'll see!

shorty · Sep 5, 2013

Stock 5.0
yea, pulled the plugs today, all look good. Also did a compression test and have 120,120,120,120,90,120,110,123.
I dont think its causing my rev issue. unless a valve isn't seating and fuel is being dumped into it?
going to check for a leak in the intake tomorrow.

and yea, i plan on spraying it again

RichV · Sep 5, 2013

Check your vac tree and all the intake soft lines. One is probably off or the vac tree is split. A Fox guy locally blew his vac tree in half after a N2O backfire.

shorty · Sep 7, 2013

Vacuum tree looks fine, as does the upper intake. Pulling the lower today. all vacuum lines look good. I was able to lower the idle before i pulled the intake to about 1100, but something still isn't right. I shouldn't have to bottom out the idle screw for it to hit 1100.