running rich and backfiring

[drez]

hows it going you all ..... ive read dam near ever post that had to do with back firing or running rich but still doesnt clearly give me a awnser..... i got a 180sx with a sr20 det... now mod wise i got the basics

hks intake
blow off valve
greddy profec b
turbo timer
trust cat back exaust
down pipe
punched out cat
greddy emange
vac gauge

now some arent proformace but non the less..... im running stock turbo with stock fuel system.....

well the emange was doing good just a little rich nothing bad but since sunday i have been back fireing like crazy.... its not at low rpm's its when i get on the throttle prob around 5000 or so.... its not one or to shots it sounds like machine guns screaming..... a buddy of mine told me the emange might have not been tuned right (it was dyno tuned by the way) and he said to unplug it... i did and its still shooting flames.... like i said if i drive normal nothing happens its when i get on it and it gets up there..... im more worried about it hurting the engine.... i plan to check the plugs tonight when i get home along with the vac lines but i dont see how it can just start up so sudden..... any imput or links at all ould be great... thanks ahead of time people......



PS

We got time trial this weekend so i need her up and runing.... thanks

[NZO]

Could be a boost leak, make sure all clamps are tight and sealed.

[s14 blacktop]

one thing it could be is if you recirc. your BOV and if its not that try testing your coils, one might of went bad.

[drez]

how do you test the coils..... could it be a timing thing.... cause its weird it only back fires at high rpm and when you really get on the gas.... also on the sr theres this knob thing if your looking at the engine from the front its on the right side on the strut tower... about 4 or five inchs down.... its above the stock boost soliend..... what is it and what does it do.....

[srpowereds14]

If it were one of your coil packs your car would be smoking pretty badly (BLACK SMOKE). is your bov recirc? or open?

[drez]

open.........................

[420sx]

like in the other thread i said, check your Bov.
and you need to recirc it. check all vacum lines, its an easy screw up.

[drez]

i checked all lines and there all good.... you think its best i just put on the stock hot pipe for now then a buy a new bov later on....... it only does it at about 4500- and above rpm at open trottle.... never on decel or idle.... it also idles at 700 solid....

[ultraDorksGarage]

i just read ur post...
is it missing or backfiring, theres a pretty big difference that point to pretty different things. check ur timing... if u dont do it like the fsm and try a timing light u gotta do the whole unplug tps thing, (get motor to op temp, shut off, unplug TPS, start motor, rev to 2500, and then check timing) otherwise the motor will have wrong timing. we set to 15 btdc for stock, but stock ecu also bumps timing up to about 18-19 when tps is at 0% and idling... so u gotta do like the manual and unplug crap.

this is important because if u set it wrong, (say at like 10 btdc instead of 15)at 4200 (i think it was, cant remember) timing begins to retard, and soon u'll be missing like crazy, even worse if it runs, and the retarded timing will have ur EGT's at about 1500+(first hand experience on that one) and noone likes the smell of toasty valves><

[Siizzzoooo]

recirc ur bov and get new, colder plugs

[Rezlo]

Originally Posted by Siizzzoooo

recirc ur bov and get new, colder plugs

As he said, BRK7es and gap them to .8mm? sound correct?

[ultraDorksGarage]

FSM := .90mm, but yeah i run ~.80mm

BOV != not the case in this one unless its leaking when boosting, recircuilating would help during release of throttle/decel. but he said its when hes actively accell above 4500 hes backfiring, which is basically where we would be boosting/ecu accomodating for boost.

[drez]

thanks for the help guys yea my a guy i know over here at a tuner shop said it might be plugs but he also metioned that it might be the actuator..... he says that since im running( or try to) .9 bars or so that the spring might be worn out or so and that it cant keep the turbine open that much so it drops it down some to around stock boost also that the emanage is trying to feed the fuel for that much boost but the air/fuel ratio is off there for back firing.... ill prob replace that in about a month or soo.... might as well do the s14 swap so no need for the actuator yet... quick question about the plugs guys is the gap how to you gap them i just bend the tip over till its .8 mm away from the little nipple itself... dumb question i know but hey gotta start somewhere.... thanks for all the help people....

[Rezlo]

Yes, try get a plug tool that has a slot in it for bending the ground strap closer, then check gap, do it slow and youll be fine, most autoparts stors sell them for like 99c pick up a little packet of anti sieze normaly by the counter and put a tiny bit on the the threads of the new plugs and dont over tighten them (make sure not to get anti-seize paste on the electrode)

My S14 200sx's BOV return was ripped out before i got the car and the BOV leaks even at stock boost at WOT making flames and backfireing and so on, so if you dont come right maybe look into the BOV spring being weak and opening slightly under full boost, mine was bad enough that even under partial throttle above 3000rpm it would stall and stutter, needless to say I got a $3 scrap yard one and stuck it in and solved the problem,

I don thing the emanage would have much to do with it because unless you messed with the settings it normaly wont just go bad, maybe you could use your laptop and plug it into the emanage and read your MAF voltage and see if it sounds normal, maybe your maf is faulty?

[Siizzzoooo]

run it gapped between .28-.32

its kind of a trial and error. see which gap your motor likes best

i had mine at .31 and it was a huge difference in power versus the old plugs