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Backfire problems on my 1994 Mustang 5.0

  • Thread starter Thread starter mustang1994
  • Start date Start date Apr 19, 2009
M

mustang1994

Member
Apr 19, 2009
58
0
6
Apr 19, 2009
#1
  • Apr 19, 2009
  • #1
This is what I did. I put 24lbs injectors in it. And this is the work I done to try to fix it. I put new plugs, new 9mm wires, new coil, new MSD cap and rotor, 2 new O2 sensors, and a 80mm MAF calibrated for 24lbs, put fuel injector cleaner, put the timing down to 12*. And it STILL backfires on normal driving.
 

toyman

10 Year Member
Jul 19, 2007
1,944
54
79
Vernon BC
Apr 19, 2009
#2
  • Apr 19, 2009
  • #2
mustang1994 said:
This is what I did. I put 24lbs injectors in it. And this is the work I done to try to fix it. I put new plugs, new 9mm wires, new coil, new MSD cap and rotor, 2 new O2 sensors, and a 80mm MAF calibrated for 24lbs, put fuel injector cleaner, put the timing down to 12*. And it STILL backfires on normal driving.
Click to expand...


And how does the PCM know you've changed injector anf MAF sizes? You may need a tune to resolve this.
 

desertcox05

New Member
Oct 3, 2007
379
0
0
south atlanta
Apr 20, 2009
#3
  • Apr 20, 2009
  • #3
double ck you firing order you could have mixed 1 or 2 up
 
H

humphrey111

New Member
Aug 10, 2008
12
0
0
Apr 20, 2009
#4
  • Apr 20, 2009
  • #4
i just changed intakes and injectors and all that too. I had a horrible backfire and it ran like poo. My problem was the vacuum lines under the intake, replaced all those hoses and PCV and problem solved. computer takes a minute to adjust to new maf and injectors but shouldnt be the cause of the problem.
 
N

NORCALBANDOG

15 Year Member
Nov 5, 2008
11
0
1
Kentucky
Apr 20, 2009
#5
  • Apr 20, 2009
  • #5
Do you have aftermarket headers installed? If you do, then check for any exhaust leaks from the header gaskets. I had an exhaust leak from a burned out header gasket that was giving me backfiring problems. As soon as I changed the gasket, the backfiring was eliminated.
 
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