SR20 Hesitation

[fliprayzin240sx]

K im out of idea here. I got a friends car and its been running like shiet under boost. it runs fine till you try to push it and it starts hesitating from 3k on.

Blacktop S13 SR with custom fmic, safcII and z32 maf
Safc set at 2-6 hi/low at 0 since its still at stock boost. Tried to play with it a bit by adding some fuel at hi map and it helped a bit but still doing it

Things ive tried and looked into:
1. double checked mechanical timing=chain marks are off but its lined up right, put it on TDC, checked cam gear markings and counted 20 links.
2. checked timing=right on 15deg
3. Sparkplugs=NGK BCPR7ES-11 started off gapped at .030 now .026 and still didnt change anything
4. swapped ecu water temp coolant=didnt do shiet
5. swapped maf=didnt do shiet
6. swapped fpr= same
7. checked maf/water wiring and its koo

Im bout out of ideas as far as wut could be causing this. Even when we went back to stock maf...it was doing the same thing. Only thing i can think of is o2 sensor but i dont think itll cause it to hesitate this bad.

[fliprayzin240sx]

No idea???????

[-usmd-180sx]

my o2 sensor is fucked to no other.. and it gives me that occasionally.. and when i wasnt running a o2 all together.. my idle died out randomly in gear.. and at stops.. O2 sensors or pesky..

Might be it.. my shit was idling really bad lastnight jumping from 200 to 900 bouncing up and down

[caall99]

i had the same symptoms, my problem was dirt in the CAS

[fliprayzin240sx]

imma try the o2 jes for shiets and giggles since im so f*ckin stumped, its not even funny. It does run better after changing plugs. Its not hesitating all the way to redline under WOT. Just around 2.8k-3k

[kazuo]

Did you even bother pulling codes before you started randomly replacing parts?

That's where you should start... always

Then start testing the various sensors and whatnot.. and hope you find something.

Try switching back to stock ECU and disable the AFC?

Boost leak? Atmospheric BOV? Dot Dot Dot? What kind of fuel system? Stock? Dot Dot Dot

Start with pulling codes and work your way out... stop replacing things when you dont know what the problem is, waste of money.

[fliprayzin240sx]

Nopes....only code the bitch threw was a 55 Art. Anyways figured it out, it was the damn o2. Now, a year later, its finally running like how it was supposed to be off the bat. Didnt know an o2 would cause it to run like ass. Always thought that the only thing an o2 will affect would be the gas mileage. Now to figure out wussup with the speedo. And Art....THANKS FOR BEING A SMART ASS!!!

[kazuo]

Originally Posted by fliprayzin240sx

Nopes....only code the bitch threw was a 55 Art. Anyways figured it out, it was the damn o2. Now, a year later, its finally running like how it was supposed to be off the bat. Didnt know an o2 would cause it to run like ass. Always thought that the only thing an o2 will affect would be the gas mileage. Now to figure out wussup with the speedo. And Art....THANKS FOR BEING A SMART ASS!!!

Well, first of all, sorry if you think I'm a smart ass, but its much easier to simply test the sensors with a DMM than replacing all this stuff randomly.

Second, if you had checked the sensors with a DMM from the start, it would have taken you 10 mins to figure out it was the o2 sensor.

Either way, I am glad you fixed the problem.

[bad240naf]

I had te same prob try to get another coil pack and swap them out one at a time i have had 2 coil packs go bad not sure if it is a common prob but it sounds the same as mine right at three and under boost.

[MaD1337M3DRiV3r]

My coilpacks + wiring went bad... it would make popping noises back to back at WOT above 3k, like a machine gun.
I had:
- changed plugs
- fuel pump
- fuel filter
- removed cat to make sure it wasnt clogged
- cleaned maf
- checked timing
- unplugged O2
- swapped ecu