That stupid sputtering problem is back!

[1wickedA70]

ok so i got my new ecu fixed the alternator wires that broke up and drove my car. it drived amazing for 1 day, the second day it was driving good but then all of a sudden it started to back fire but the boost would fight through it. then the following day the backfiring got a lil worse..but still fighting throught the RPM's, then soon after here we go again, she starts to sputter as soon as i hit full boost! wtf is the problem now? why would she drive great for 1 day and then all of a sudden it would start to sputter like before .

i've noticed that when i hit full boost my battery voltage would go from 13.9-12.7ish, its this normal? i didnt look at the battery voltage when my car was driving good for that one day so i dont knw what normal is. also i checked my plugs they werent fouled out. and just to rule out the coil packs im gonna switch with my boys 2j, but i knw thats not the problem. cause then my car would of been sputtering all along and not drive good for just that one day. im also gonna switch ignitors, but im pretty sure thats not the problem either.

HELP!

 

[1wickedA70]

also i dont have the "12 volt mod" on the fuel pump..can that cause it? sometimes the fuel pump is much louder than normal at times when the car is idling..is that normal?

 

[IBoughtASupra]

......It is infront of your face. Everytime I look at your engine bay, it is right in front of you. Won't come back in here, so you can shit talk all you want.

 

[Silvermk2]

Check your spark plug gap. My 2JZ does the same thing, its only really happy with around .025 gap.

 

[1wickedA70]

......It is infront of your face. Everytime I look at your engine bay, it is right in front of you. Won't come back in here, so you can shit talk all you want.

OMG! will u get the fuk out of my thread. u seen the bay like on time asshole..plus clearly it stoped breakin up then it came back after a couple of days when i put my new ecu in..idiot.

and no silvermk2 sadly its not that simple..i changed and gapped plugs a million times already

 

[1wickedA70]

could it be my fuel pump not gettin enough voltage to perform under full boost? today i just learned in first and second if im on the throttle 45-50% it will hit full boost and not break up..i have no 12 volt mod on my fuel pump, any 1j's had that problem when the car was breaking up do to low voltage from the fuel pump?

 

[mk3tattoos]

ecu could of failed agian, i would open it up just to rule it out for now.

 

[JonoTurbo]

It could definitely be your coils, have you swapped them out yet? When mine were cracked, the car would run fine at idle and then break up under boost.

 

[1wickedA70]

It could definitely be your coils, have you swapped them out yet? When mine were cracked, the car would run fine at idle and then break up under boost.

i never did, but i guess ill do it just to eliminate that. i checked them they look fine. plus my car ran good for 1 day after it wasw parked up for 2 months with no ecu, then slowly went back to sputtering. if it were coils wouldnt it be sputtering right off the jump? instead of driving good one day then going bad.

 

[kuwugata]

Ive had your problem before. It was a crack on the coil. A bit of clear nail polish fixed it (and a very confused sister)

 

[OneJArpus]

^LOL... was it cooler that day when it drove better? The coils heat up if it was cooler then the cooler air prevented the coils from getting extra hot. It "could" be the coil but!!!! I hav eno clue i have the same issue and i have a new coil and recapped ecu, i've tried different ECU, MAP, and Ignitor =/

 

[1wickedA70]

sadly it wasnt cooler, i remember that day being around 70 degrees, and now its like 40 sumtin degrees at night and still breaks up haha...i gotta try the coils as soon as i get a chance to switch with my boys 2j. i hope its nuttin major..my other boy with a 1j has the same problem and he literally swapped everything from his brother's 2jz car which is running amazing and still no fix :/..he even up and bought an hks DLI, and still no fix! this seems to be a 1j..maybe well have to get 2j's to fix it haha

im thinking tho. maybe because i havnt driven the car in so long the coils were really cold and not used to the heat that it drove good for that one day, then it slowly went back to its normal state. does that make any sense to you guys? because it kinda makes sense in my head. i did wrap electric tape around them a couple of months back, but never tried the clear nail polish.

 

[perpetualthought]

if u swap coils and the coils happen to be the problem ; go to home depot and get the shrink wrap the needs a torch to shrink, this worked perfectly for me.

 

[1wickedA70]

quick update on my problem. i havnt had time to switch the coils yet..but for sure on friday or saturday i will..ill be sure to keep you guys posted. i really hope this is the problem. I dont think its my fuel pump anymore cause my car doesnt lean out at all under boost.

 

[super.secret.supra.club]

have you checked your wideband. sound like same problem i had. it was leaning out too much

 

[1wickedA70]

PROBLEM FIXED! it was my coil packs all along lol..i just never bother trying to switch them because i had checked all of them and they had no cracks..i switched them with my boys 2jz coils and the car drives great! despite having having a crack on one of the coils ?? anyway im gonna gonna question it lol

 

[super.secret.supra.club]

thanksfor the update