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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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347 efi back fireing through intake

  • Thread starter Thread starter watchdogfour
  • Start date Start date Dec 6, 2008

watchdogfour

New Member
Nov 11, 2008
49
0
0
bgky
Dec 6, 2008
#1
  • Dec 6, 2008
  • #1
My new motor keeps back fireing through the intake it does it under a load i have replaced every sensor on it and had it tuned I am stuck because I have nothing else to replace.thanks for any help
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 6, 2008
#2
  • Dec 6, 2008
  • #2
Valve train . Back fire is normally caused by wrong timing or a stuck valve .with engine just being built you might need to do a cyl leak down test .
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 6, 2008
#3
  • Dec 6, 2008
  • #3
Your dizzy is the other thought .you say misfire under load.maybe pull dizzy and ck gear on shaft and for internal pieces .
 

watchdogfour

New Member
Nov 11, 2008
49
0
0
bgky
Dec 6, 2008
#4
  • Dec 6, 2008
  • #4
.

ive tried two diffrent dis. i dont think its a stuck valve cause it does not do it all the time ive replaced o2s mass air coolant temp all new tune up tps fuel pump i dont know what the hell it is.
 

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
Dec 6, 2008
#5
  • Dec 6, 2008
  • #5
Its hard when you have changed most parts.ive heard a map can do that but you dont have that type .are thier anycodes at all.if it was me i start with basic compression ck and leave gauge on each cyl .while doing so ck plugs and wires.a back starts from inside engine and seems ignition related . Weak spark or interrmitted spark.
 
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