dsm10o0
Well-known member
Have this little problem going on. The car is all stock right now besides a 16g, ported 2g manifold, and o2 dump. The car runs good when regular driving, but if I do a quick pull in any gear, it starts jerking at 4k
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Jerking at around 4k rpm
- Thread starterdsm10o0
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mitsuturbo
Well-known member
boost leak?
caps in ecu?
fuel pressure?
knock sensor?
spark delivery?
Check those things if you have not already.
caps in ecu?
fuel pressure?
knock sensor?
spark delivery?
Check those things if you have not already.
dsm10o0
Well-known member
Did look at it today. Had a little boost leak, got that fixed, still the same. I got 3 different ecus and it still jerks with a different ecu. I had a boost gauge on it, I took it out and it ran better for a bit then started jerkin again. Knock sensor is good. Have no CEL code. And for spark, It has new ngk bpr6es's, wires are still pretty new, coil pack seem to be good. im kinda lost on this problem.
mitsuturbo
Well-known member
Plug gap is good, i assume. Wires are not leaking, i assume. ECU is not the issue, i assume.
There's no boost leak, you say.
4k can often be right where boost comes on. What kind of injectors/turbo are you running? MAF? /ubbthreads/images/graemlins/dunno.gif
check all your grounds, also
sorry i don't have much to offer... just going with the basics here
There's no boost leak, you say.
4k can often be right where boost comes on. What kind of injectors/turbo are you running? MAF? /ubbthreads/images/graemlins/dunno.gif
check all your grounds, also
sorry i don't have much to offer... just going with the basics here
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dsm10o0
Well-known member
Yeah, plugs are gapped to .028. Its on the stock 450cc injectors. The car is bone stock beside a b16g, ported 7cm housing, ported 2g manifold and an o2 dump. Its running on the stock 14b wastegate. When it still had the 14b, it didnt have this problem but the turbine housing on it was super cracked. I will check the maf tomorrow as well as the grounds. Will also check the vacuum routing.
FlyingEagle
Staff member
Log your injector duty cycle at the RPM threshold where it starts to act up, and see what you get. Every car that runs the 16g turbo's started with the 510cc injectors and larger.
Log will help either way.
Log will help either way.
dsm10o0
Well-known member
I don't have a logger but I'll be putting in a set of evo injectors and see if that helps.
dsm10o0
Well-known member
Today, i changed the resistor, coil pack, check the vacuum routing and its still doing the same thing. Also, a CEL code popped out today while i was test driving it. Its code 12 and 43. Air flow sensor and EGR valve. I took out the EGR valve couple days ago and cleaned up all the carbon build up inside and its still doing the same thing. The MAF i unplugged to see if i could run it on limp mode to see if ill get rid of that but it didnt. Put it back in and now its throwing code 12 for MAF. Ill reset the ecu out tomorrow to see if itll clear the codes, if not, ill swap out the MAF.
dsm10o0
Well-known member
Anyone? Haven't got the injectors changed yet but I did change the fuel pressure regulator but nothing has changed. Did a compression test and they're all 140+ psi across.
Please help! /ubbthreads/images/graemlins/frown.gif
Please help! /ubbthreads/images/graemlins/frown.gif
cheekychimp
Well-known member
I understand the difficulties that you are having and the frustration it causes especially if you don't have a logger, but the guys have offered some good advice here and until you check the things that they have suggested it is difficult for them to advise further.
This 'could' be a fuel delivery problem. You are using injectors that were not considered large enough by the factory to support that turbo. Remember your AFPR can only work with the fuel pressure that you supply it. It is not a pump. So if your fuel pump is dying or your injectors are maxed out, your AFPR isn't going to be able to compensate.
Check your fuel filter first (or just get a new one, they aren't expensive). If that doesn't solve it try to get or borrow a logger and check injector duty cycle to see if your 450s are coping or not. If those are maxed out you likely need bigger injectors but you need to be able to compensate for those (do you have any way of doing that on your setup?) If the 450s are not maxed out, start looking at the fuel pump. If it is dying but not dead it may well support idle and a smaller turbo but struggle now you have a larger turbo on.
Can you pull past 4K and pull out of it, or does it just fail to get past 4K?
This 'could' be a fuel delivery problem. You are using injectors that were not considered large enough by the factory to support that turbo. Remember your AFPR can only work with the fuel pressure that you supply it. It is not a pump. So if your fuel pump is dying or your injectors are maxed out, your AFPR isn't going to be able to compensate.
Check your fuel filter first (or just get a new one, they aren't expensive). If that doesn't solve it try to get or borrow a logger and check injector duty cycle to see if your 450s are coping or not. If those are maxed out you likely need bigger injectors but you need to be able to compensate for those (do you have any way of doing that on your setup?) If the 450s are not maxed out, start looking at the fuel pump. If it is dying but not dead it may well support idle and a smaller turbo but struggle now you have a larger turbo on.
Can you pull past 4K and pull out of it, or does it just fail to get past 4K?
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belize1334
Well-known member
Have you set your base timing? If you're getting a MAF code, it could be that your MAF is messed up. Also, do you have a boost gauge? If not you could be getting boost creep without realizing it which could put you in a lean condition if it rises into the 15+ psi range. Try rewiring your fuel pump and see if that helps.
dsm10o0
Well-known member
Little update.
I took out the fuel pump today and it was really rusted out. I swap it out with a walbro 190 and the car runs really shitty. It would just idle then die. If i give it gas, it chocks like its running out of gas.
I looked up the part number on the old fuel pump and it cam out to be a 3000gt non turbo fuel pump. Would this cost my problems? Part number 195130-2020 denso
Im going to put in a stock 1g dsm fuel pump tomorrow to see if it will get better or worst.
I took out the fuel pump today and it was really rusted out. I swap it out with a walbro 190 and the car runs really shitty. It would just idle then die. If i give it gas, it chocks like its running out of gas.
I looked up the part number on the old fuel pump and it cam out to be a 3000gt non turbo fuel pump. Would this cost my problems? Part number 195130-2020 denso
Im going to put in a stock 1g dsm fuel pump tomorrow to see if it will get better or worst.
Brunoboy
Well-known member
maybe your flooding the motor? I have the injectors, Ill see you tomorrow when I drop it off to you
dsm10o0
Well-known member
I swapped out the walbro 190 with a stock 1g dsm fuel pump and the car runs much better. It still jerks on some wot pulls. Also put in a set of evo injectors and it still does it. If I make a hard or quick turn and accelerate after, it would just stall and it like chokes.
you have a bad maf most likely. karmen vortex is silly you should prolly try atleast two known good ones
Brunoboy
Well-known member
thats what i was thinking with my car ^ I have the same problem, and Ive replaced everything but the Maf. Let me know how it goes Nico.
