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shelby2 · 09-04-2001, 01:19 AM

maybe some of you guys can help me. i am still having backfiring problems with my sefi converted 67. i have found out that it doesn't do it so much if i have the fuel pressure around 50-52 and the timing quite advanced. however, i don't want to do this because the idle surges and spits out raw fuel (makes it look like i burn oil).

i do have a jms chip for my computer but it doesn't seem to be helping. i am thinking of sending it back for a reprogramming.

also, the other night when i was cruising around, it would backfire at pretty much any rpm. i turned my heater on to try to keep the engine temps down and it didn't backfire once, so i have a question. does anyone know if bad ect or act (temp sensors) that read too hot could make the computer retard the timing or lean out the air/fuel ratio. i have a 180 deg stat and was thinking of going to a 160. i am thinking it is detonating from being lean, but am not quite exactly sure what detonation sounds like.

if anyone has some kind of info or experience with a problem like this, i would really appreciate it if you could leave some info. i won't be able to reply back though until after 5:00 pm central time.

------------------
shawn hill
1967 ford mustang coupe, red w/white stripes, hood scoop, front and rear spoiler, sefi and c4, trickflow intake, 70mm mac tb/egr, billet fpr, 24# inj, c&l maf, heavy duty c4 w/transgo shiftkit, msd 6a box w/tfi blaster coil, flowtech longtubes w/turbo mufflers, t-rex inline pump, ported and polished E7TE heads w/1.94,1.60 valves, lunati 292 cam, harland sharp 1.6 rollers, conventional 8" with 2.79 gears (soon will be gone)

09-04-2001, 01:19 AM	#1
shelby2 Registered Member Join Date: Nov 1999 Location: O Fallon, IL Posts: 87	backfiring problem continues (long) maybe some of you guys can help me. i am still having backfiring problems with my sefi converted 67. i have found out that it doesn't do it so much if i have the fuel pressure around 50-52 and the timing quite advanced. however, i don't want to do this because the idle surges and spits out raw fuel (makes it look like i burn oil). i do have a jms chip for my computer but it doesn't seem to be helping. i am thinking of sending it back for a reprogramming. also, the other night when i was cruising around, it would backfire at pretty much any rpm. i turned my heater on to try to keep the engine temps down and it didn't backfire once, so i have a question. does anyone know if bad ect or act (temp sensors) that read too hot could make the computer retard the timing or lean out the air/fuel ratio. i have a 180 deg stat and was thinking of going to a 160. i am thinking it is detonating from being lean, but am not quite exactly sure what detonation sounds like. if anyone has some kind of info or experience with a problem like this, i would really appreciate it if you could leave some info. i won't be able to reply back though until after 5:00 pm central time. ------------------ shawn hill 1967 ford mustang coupe, red w/white stripes, hood scoop, front and rear spoiler, sefi and c4, trickflow intake, 70mm mac tb/egr, billet fpr, 24# inj, c&l maf, heavy duty c4 w/transgo shiftkit, msd 6a box w/tfi blaster coil, flowtech longtubes w/turbo mufflers, t-rex inline pump, ported and polished E7TE heads w/1.94,1.60 valves, lunati 292 cam, harland sharp 1.6 rollers, conventional 8" with 2.79 gears (soon will be gone)