Back Firing/sputtering. Slug Gtr :(

[shaunpierre]

ok ... this probs has been coming and goin past months and iv tried every thing to fix it

basically up until about 3,000 rpm cars is ok after that it sputters and lags and back fires.. some times ill be lucky and i get a clean rev to about 5,000 and then its like papapapapapa like in sitting on the limiter... occasionaly ill get back fire when im changing gears.

its totaly random.. cold hot rain it comes and goes.

car is stock! 150kms. has concept cat back exhaust

changed afm to newer un-opened ones

re soldered both old and new afm

new spark plugs ( bosch coppers ) ill check to see the gap on them again, but im sure there .8

new coil packs (33gtr)

was using de cat with sensor line on it but wasnt conected to pass rwc then changed back to high flow. there was a small gasket leak on the cat which made back fires massive! but fixed that too

i dont know what else to change i think its afm again or fuel pressure regulator??? any sugestions?? i saw a thread below cracked coil packs i dought that the 33 ones are stuffed also.

pm or reply with any sugestions thanks guys

[paulr33]

moved from tutorial - dont post "please help" in here

[SiR_RB]

could be the ignitior if youve changed to working coipacks and new plugs

[DVSTRK]

+1 ignitor

[Excuses]

My bet is on the fuel pump / regulator, quite possible it is blocked at points in time, have you ever drove the tank down to the fuel light?

If not, have u tried changing your airlines?

[shaunpierre]

few times light has came on but never solid continues light. it varies with temp also the back firing. i put a front pipe on...it helped a little i think may be O2 sensors??? or maybe my zorst is too large???? its 3.5" cat back planing to get rid of it somthin smaller maybe 3"

one thing at a time.. its not as bad as it used to be

Edited April 16, 2012 by shaunpierre

[shaunpierre]

fuel economy isnt bad when im a grandma mode but when im casual week end drive is fkn terrible fml also like 30+ cm flames when nice and hot

[Godzilla34]

Lol nice flames

[Godzilla34]

Sounds like a blocked cat converter or something

[Godzilla34]

Sounds like a blocked cat converter or something

[Bsa]

Won't be blowing flames if the cat is blocked check fuel pump filter intank

[shaunpierre]

yea willl do, its something small and simple. getting about 13-14 leters per 100kms but ALOT of black smoke and poping

[DVSTRK]

have you tried a new ignitor?

[DVS JEZ]

Check for airleaks