Bad Jerk/BackFire on 3rd gear pull with WOT

[EmpireElite]

Okay guys here is my issue, it has happened a few times so i just don't do 3rd gear pulls anymore as it scares the life out of me.

First time it happened is when i took off after a skyline on the highway on ramp. Was going WOT in 3rd and around 6k rpm its just a huge jerk like....okay i have no clue how to explain it but it makes you shit your pants.

Needless to say i left off the gas and the skyline got away (like i was gonna catch him, ran into him later and he was pushing 500whp+)

When it happened my buddy was behind me and i shot a large ball of spiral black smoke from my exhaust, I dont know if the smoke was from whatever happened or from when i let off the gas. The car ran fine afterwards with no problems and no check engine light.

I recently tried it again but told myself to continue gas to see what happens and it continues to pull after the jerk. So i dont know if im hitting a fuel cut or this is a back fire. Im currently waiting to hook up my AFR to see if that gives me any answers. Figured i would post on here to see if you guys have any ideas.

Basically im running a 16g turbo at 19psi on stock engine. I have a 255lph fuel pump with aem fuel rail and fpr. Stock injectors currently.

Ive added all the info i could, let me know if you need anymore information.

 

[99gs420a]

Are you running a stock turbo manifold ? I recentaly has some shit mani crack on me and i would get a huge back fire, extremely lean condition, all this would happen between 4500-6000. After i put the stock one back on it ran like a dream.

 

[EmpireElite]

i actually am running a tube style exhaust header. Ill have to look into that to see if i have any cracks. Thanks

 

[96awd]

i actually am running a tube style exhaust header. Ill have to look into that to see if i have any cracks. Thanks

What are you tuning with? Seems to be a fuel cut or misfire. What plugs are you running? Gap? Same was happening to me until I started running BPR7ES and gapped them to .18. Given, I was running bigger injectos, 57 trim at 28psi w/ link and HKS 272

 

[stefanOst]

Are you running any sort of tuning device? 16g at 19psi seems a bit much for the stock injectors to be able to handle, especially without some tuning. Also, what fuel pressure do you have set with that 255lph fuel pump? You could be dumping tons of fuel into the system and running way rich, which could explain the black smoke.

 

[99gs420a]

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This is the crack i had completely broken around the pipe.
And time i went WOT and tryed to get it into boost i would smell burning paint

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It was the paint on my hood boiling. Fun times

 

[XiKeiyaZI]

.... Wow.

Okay, so you're running a 16G at 19PSI with STOCK injectors? Let me tell you as bluntly as I can what that's called : Fuel cut.

The injectors are maxing out. Your ECU see's this and goes " Nope. Not having this. " Cuts fuel.. and you hit a proverbial 'brick wall'. This is not a hardware malfunction, this is a driver error. A 16G, regardless of fuel pump, is not going to run 20ish PSI on stock injectors all the way through red line in 3rd gear. Period. I've seen 14b's cause fuel cut at 16PSI on a rewired fuel pump. You need to turn the boost down, look into some sort of better tuning device, and get larger injectors. This is, of course, if you don't want to destroy that engine...which from the sound of it I can't believe it hasn't detonated yet.

Just to add : Boost leaks can also contribute to this. Just.. tossing that out there in the event you want to go with something else besides the boost level and lack of supporting mods being the cause for your issue.

 

[EmpireElite]

Haha okay that's what I figured, thanks for the help. I don't plan on turning down the boost as its way too much fun and the engine seems to be having no problems. Ill plan on upgrading the injectors soon. I figured it was that but wanted to make sure. Ill just not do third gear pulls, not like you actually hit full boost when driving in toronto. Its all a work in progress and learn on the way.

And to answer the other questions, no tuning has been done yet but I'm just gonna do basic tuning with a aafc. Just played with the boost till I got something that it ran nicely on. Yes I know not smart but I'm learning on the way. And to add the engine has 170k miles on the engine.

Appreciate the help guys. What injectors would you suggest? 550's?

 

[XiKeiyaZI]

Do it right. 800+'s....though with a SAFC the most you can compensate for are 650's.

 

[my dreamt dsm]

Don't risk it. Sure it's fun but it's not to fun when your adding the money that could of went to the injectors for a blown motor. Just a thought. Good luck!

 

[rlacasse1]

You're definitely running to much boost on a stock fuel system and no tuning.

But, I also have to add this.

I think it's a boost leak. You said when it happened your friend saw a large puff of black smoke come out the tailpipe. Black smoke means your car is burning rich. So, that being said, I bet you have a boost leak, and when it loses that air you go rich for a second.

It explains the jerk and the black smoke.

This does not mean to just fix your boost leak and pound on your car.

You will still blow it up if you don't improve your fuel and tuning.

 

[96awd]

Don't risk it. Sure it's fun but it's not to fun when your adding the money that could of went to the injectors for a blown motor. Just a thought. Good luck!

Take this guys advice. You will fvck up your motor. Might not seem like it not but if you keep going, you will. Turn the boost down and don't risk it.

 

[scott90gsx420]

WOW. If you want to keep that car running turn the boost down to like 15tops. It will still be fun just not as much. You think its running 'ok' but its really saying hey asswhipe, how would you like it if i came out and started hitting you on the head with a sledge hammer(which is exactly what your doing, theres no way your not detonating and causing damage)fuelcut is there to save your motor if you wanna ignore it go ahead. Is it funner to run 19psi for a month(rhetorical number) and blow the motor then it is to run 15psi for however long untill you get your 200dollar injectors. Just order a set of evo 560cc injectors they be enough to top that turbo out and not risk the motor. Especially with the 255 and afpr. There really cheap like 100bucks and there plenty for that turbo.

 

[Eeeeky]

I don't plan on turning down the boost as its way too much fun and the engine seems to be having no problems

Uuuh dude...You see the damn thread you started about this "bad jerk/backfire"??? Thats the problem, that it IS having! It may be fun, but its going to destroy your car, and youll feel realllllly stupid posting a thread about "well it blew up and i should have taken the advice i was given" Please please just turn it down, before you hurt the car.

 

[EmpireElite]

Hey guys its clear i came off on the wrong page by making it sound that i don't give a damn about the car. Like i said before this "jerk" has only happened twice as i dont push this car at all in its current state. The car barely hits 10psi while driving as i am going for mpg's at this point with gas the price it is. The car is a work in progress and injectors are the next thing on the list. I realize there is a problem and just take it easy on the car till i correct it.

When i did happen the first time i did turn down my boost. I have a boost tee and i turned it down 3 clicks, i then got in the car and reved it just to make sure all was good. At 3k rpm the engine started to bog, i said wtf? turned the boost tee back to where it was and reved the engine without a problem. I was confused as hell as this may no sense to me and then just left it. She has a mind of her own and i let her do her own thing.

My main reason as for the injectors not being done yet is money. But it is the next thing on the list

Rlacasse i think you are on to something there as my boost does creep down a bit, sometimes. Another thing i have to look into and fix.

Keiya - Yeah i really dont have the money to upgrade to a better tuning system so 550-650 will be my limit for this time. Most likely go with the 550's. Im using the Apexi Neo Afc so i should be okay hopefully. Time will tell.

Also Rlacasse the fuel system isnt stock, only thing left stock is the injectors really. Fuel pump, lines rail and fpr have all been upgraded.

and im gonna look into those evo injectors you mentioned scott.

Basically once i can my money from my grandmothers will i can get back on page with the build.

yet again guys i didnt mean to come off as the asshole who just wants to boost the shit out of my engine for a few good laughs. Just one of those days. Appreciate the help though.

 

[scott90gsx420]

Hey guys its clear i came off on the wrong page by making it sound that i don't give a damn about the car. Like i said before this "jerk" has only happened twice as i dont push this car at all in its current state. The car barely hits 10psi while driving as i am going for mpg's at this point with gas the price it is. The car is a work in progress and injectors are the next thing on the list. I realize there is a problem and just take it easy on the car till i correct it.

When i did happen the first time i did turn down my boost. I have a boost tee and i turned it down 3 clicks, i then got in the car and reved it just to make sure all was good. At 3k rpm the engine started to bog, i said wtf? turned the boost tee back to where it was and reved the engine without a problem. I was confused as hell as this may no sense to me and then just left it. She has a mind of her own and i let her do her own thing.

My main reason as for the injectors not being done yet is money. But it is the next thing on the list

Rlacasse i think you are on to something there as my boost does creep down a bit, sometimes. Another thing i have to look into and fix.

Keiya - Yeah i really dont have the money to upgrade to a better tuning system so 550-650 will be my limit for this time. Most likely go with the 550's. Im using the Apexi Neo Afc so i should be okay hopefully. Time will tell.

Also Rlacasse the fuel system isnt stock, only thing left stock is the injectors really. Fuel pump, lines rail and fpr have all been upgraded.

and im gonna look into those evo injectors you mentioned scott.

Basically once i can my money from my grandmothers will i can get back on page with the build.

yet again guys i didnt mean to come off as the asshole who just wants to boost the shit out of my engine for a few good laughs. Just one of those days. Appreciate the help though.

Its all good im sure i speak for everyone on hear when i say were not trying to be d**ks to you we just don't wanna see your car dye or see you have to deal with it dying, and probably push you away from the dsm scene.
Ya man check out the evo forums there always on there extremely cheap because there the evo 8-9 injectors(maby other years idk) and the evo guys cant run them on to much extra boost but the evos come with19psi stock on the evo16g turbos. They also come with 43psi base fuel pressure just like the 2g dsm. Those guys turn the car up to 24-26 ive heard before they have to upgrade fuel system parts. Ive got my afpr turned to 46psi just to give me a bit extra tuning room. . So if your looking to max that turbo these injectors will work great, and theyll make tuning with the afc a lot easier then with 660's. I also have a 2g mas so my afc settings are way low. Maby look into grabbing a evo mas while your at it.

 

[EmpireElite]

Okay i am back, what a busy week.

So im on the search for some injectors, not sure exactly what ones im gonna go for yet but the evo ones do look like a good possibility for my goals right now. Gonna get them soon as i know how easy injectors are now.

Thanks for all the help scott.

Btw will the evo mas work without any modifications? and what difference will it have? i know this is a bit off topic but i figure its okay to ask here.

Thanks again all

 

[scott90gsx420]

The evo mas will work but i beleive it does have to be modded to do so.

 

[EmpireElite]

okay ill look further into it. thanks

 

[twotall]

ok so im having same kinda broblem, in 3rd i hit full boost then WOT and about 43k-5k rpms it backfires or mis fires im not sure how to tell feel like i hit a wall, im running stock boost fmic exhaust intake stock injectors, im thinking it might be my fuel pump if its backfire ###, my fuel lights goes on an off? an ideas what the problem is

 

[98mitsubishigst]

ok so im having same kinda broblem, in 3rd i hit full boost then WOT and about 43k-5k rpms it backfires or mis fires im not sure how to tell feel like i hit a wall, im running stock boost fmic exhaust intake stock injectors, im thinking it might be my fuel pump if its backfire ###, my fuel lights goes on an off? an ideas what the problem is

This was happening to me, idk if it still has considered i have only done 1 WOT pull since ive put the new parts on..

Thanks to a friend on here, I now am running 272 cams 16g turbo and DSMLINK..

I did one pull, and it did not happen to me, But who knows...
Check your manifold.. i have a crack in mine and that could be what's causing it..

Or Boost leaks, Not enough fuel.. Etc.

 

[twotall]

kay thanks i will check my manifold, do i need to keep the heat shields on there, my friend told me i dont have too but i dont want to take them off an melt stuff, ima re do all my clamps too, an ###### buy the walbro 255, thanks for the help bro

 

[98mitsubishigst]

kay thanks i will check my manifold, do i need to keep the heat shields on there, my friend told me i dont have too but i dont want to take them off an melt stuff, ima re do all my clamps too, an ###### buy the walbro 255, thanks for the help bro

Na, you don't have too.. Alot of us do not have ours on..
But if you can find a clean shield, it cleans up your engine bay real well.

 

[twotall]

so im thinking it could be bad gas in my fuel system or, even a bad fuel pump. my gas light will come on an off, an wont go below 1/4 tankline. would it be ok to run a walbro 255 on my stock turbo an stock injectors? i plan on upgrading to a 16g not for awile though dont so. thanks kyle

Na, you don't have too.. Alot of us do not have ours on..
But if you can find a clean shield, it cleans up your engine bay real well.

so im thinking it could be bad gas in my fuel system or, even a bad fuel pump. my gas light will come on an off, an wont go below 1/4 tankline. would it be ok to run a walbro 255 on my stock turbo an stock injectors? i plan on upgrading to a 16g not for awile though dont so. thanks kyle

 

[98mitsubishigst]

so im thinking it could be bad gas in my fuel system or, even a bad fuel pump. my gas light will come on an off, an wont go below 1/4 tankline. would it be ok to run a walbro 255 on my stock turbo an stock injectors? i plan on upgrading to a 16g not for awile though dont so. thanks kyle



so im thinking it could be bad gas in my fuel system or, even a bad fuel pump. my gas light will come on an off, an wont go below 1/4 tankline. would it be ok to run a walbro 255 on my stock turbo an stock injectors? i plan on upgrading to a 16g not for awile though dont so. thanks kyle

with a 255 u need a FPR