Backfire on hard accel at 4000 rpm
 

Just wondring if anyone ahs run into this issue .Car is 90 lx 5.0 stock heads and cam off road h pipe magnaflow cat backs . CAI 70mm tb and trickflow street heat intake timing is at 10 btdc . AOD w/3.08 gears .It is load and rpm effected if engine load is low and rpm is at 4000 will not pop thru intake .Does not feel like it is starving for fuel idles great and cruise great just when you mash throttle to the floor and it gets to around 4000 to 4500 it will pop thru intake.also has stock injectors thanks

RE: Backfire on hard accel at 4000 rpm
 

Well I had a similar problem a few years back with another Stang I had, It turned out to be a blown head gasket. Don't ask why or how it was determined, but the guy was right. It only happened at a high RPM. When I took the head off the gasket was blown between the 6th and 7th Cyl... This doesn't meen this is your problem, but it's something else to think about. Synyster

RE: Backfire on hard accel at 4000 rpm
 

Thanks for the info and yes I agree your car looks better in the white lx trim

RE: Backfire on hard accel at 4000 rpm
 

Thanks man

RE: Backfire on hard accel at 4000 rpm
 

Sounds like you need to bump timing up to 12 or 14 deg

RE: Backfire on hard accel at 4000 rpm
 

is your cap and rotor any good? might have a crack, mine did something like that.

RE: Backfire on hard accel at 4000 rpm
 

I am goimg to try and upgrade the ignition first and retest it.I did notice it with the stock intake , the backfire seems louder since I upgrade to the Trick flow intake . Thanks for the reply

RE: Backfire on hard accel at 4000 rpm
 

Installed MSD blaster coil and Dist ca and rotor ,cked dist shaft for wear cks good. Any new ideas I am all ears .This is my first Mustang and I really like the car just cant run at the track till I get this issue fixed Thanks[&:]

RE: Backfire on hard accel at 4000 rpm
 

u check the fuel pressure?

does it smell? running rich?

RE: Backfire on hard accel at 4000 rpm
 

Not yet but that makes sense ,fuel pump and regulator are stock ,it is weird miss pop sound nad only under wide open throtlle .Thanks ;)