back fire

[pedley]

i got an 88 gt that keeps back fireing in the intake when its underload or when i dont give enough gas in firts gear, and if i let it lug in any gear then step on it.
any ideas anyone
could there be bad codes in it or what???

[bottlebaby91]

Check your timing.

[Old Guy with 87 GT]

my car is doing the exact same thing ........in my case i'm pretty sure its from bent or sticking valves

.....the backfiring/missing started from a higher rpm and started to progress torward the lower rpm range the more i drove it .........it misses at idle and carrys on missing/backfiring the more i put the engine under load....i'm pretty sure with mine its bent valves becouse one the heads thats on mine isn't properly set up for my combo (missmatched valve springs ..long story).......after reading the symptoms you described i'd look into it ....mine does allmost the same thing you described

[Jeff Cardwell]

Hello,
I have a 93 5.0 5-speed convertible that was doing almost the same thing. It would bakc fire then run better come to find out that the fuel injection harness grounds to the back of the drivers side head was loose and arching. It was not making a good ground for the MAF either. The ground attaches to the drivers side head just to the inside and under the crossover tube for the emmisions. Hope this helps.

Jeff Cardwell
Thunder Valley Mustang Club

[pedley]

mine doesn't miss or anything its just back fires and not all the time just once and awhile
my timming is set at 14 degrees is that may be to high if so what would be good

i have that ground on my upper intake so is it hard to get at from the top ?
it goes just under the crossover tube or above it?
does it get put with the ground that goes to the fire wall?