backfiring issue

ok i just bought a 92 vr-4 with about 180k on the body and about 70k on the motor and tranny. It runs strong and sounds great. but this morning after i let it warm up i took it out for a drive and i noticed that  when i punch it and the rpms reach 5-7k it starts to backfire. and it only does this in first. actually it might have done it once in second too but it always does it in first and only when i punch it. If i push the throttle about 3/4 of the way it runs strong and doesnt bog out or backfire. so heres my questions what is causing this problem and second what should i do maintance wise that might fix it?? 

Do you have an aftermarket exhaust? It might just be normal : )

I would change the plugs and wires.
A list of mods would be good though.

I dont even think thats needed. Its a turbo car... and it backfires... no suprise there

That's true.  A free flowing exhaust will allow that.  On a stock exhaust with the cat, not so much.  Especially not on a 4g63 motor.

VR4 = 6G72 : P
 
Well cats sometimes go bad.....

quote:

ORIGINAL: Sebba

VR4 = 6G72 : P

Well cats sometimes go bad.....

D'oh

ok well my exhaust is stock actually everything is stock on it. i do have the tour mode thing though and usually i just leave it on sport. Also i noticed that im only getting exhaust out of my left side pipe and the right one isnt letting out anything. well it lets out a little bit but not like the right side. is this normal because the guy i bought it from said that if i turn on the touring mode it will open both pipes but when its on sport mode its only one pipe. Also it looses power when it starts to backfire. Could it be a clogged cat and if it is do i need to replace it? Sorry if this is a dumb question but im totally new to these cars and i dont have the first clue on them. thanks

You have an exhaust leak. More than likely the Y pipe has rusted through or come loose... bypassing the cat.. and thats where the back fire comes from.

Agreed with Seb.

i checked the pipes and there is no rust.. Where could the leak be and how would i find it? i am losing a good amount of power when it does this its like its bogging out but only between 4500 and about 6k and then it runs fine. Also i noticed that it doesnt do it so much when its cold outside becuase during the day it will do it most of the time but at night when it cools off it runs fine and will only do it sometimes. Im going to change the plugs and wires tomarrow to see if that helps..

No check engine light im guessing?
 
This either sounds like a boost leak or a bad o2 sensor... what one im not sure

no the check engine light isnt on. man i hope i dont have boost leak.. doesnt that mean i gotta rebuild the turbos? if so how much does that run and would it be around the same price as buying some upgraded turbos?

No all it means is that there is a small air hole in the piping. If you wish to do it yourself, you can make a boost leak tester.
 
Any major smoke from the exhaust?

oh ok i thought it was more serious than that. but  theres no smoke except a little bit before the car warms up but after that theres no smoke. could it be a dirty air flow sensor thats what a mechanic friend said to check.

It is my belief that it would trigger the check engine light. I think a boost leak is far more likely

I have this same problem on my car i pulled out the cat and put in a test pipe. im thinking its doing it because of that and i was going to buy a high flow cat to see if that would help. does anyone know that might be the problem?

HIgh flow cats are a wate of money...NO they are pointless

what can i do to stop the backfire. if i get a ecu reflash would that help.. and if my turbos are leaking how can i check for that

Your turbos are not leaking. They are connected to pipes so that the pressure they create is transfered back into the engine... what im saying is... in this guys case there is a leak on the pressure lines some place.
 
Backfiring on a turbo car under hard acceleration is PERFECTLY normal.

yea but not in my case. mine is abnormal the boost guage bounces from 4 - 16 after 4k rpm somethings wrong

well i think i fixed the problem. i just filled up my car today with 93 octane and octane booster and now my car isnt backfiring or bogging out at all. i dont know if that had anything to do with it but it stopped about 5min after i filled it up.

What where you putting in it before?

i was putting in 91 octane because where i live theres only like one gas station that sells 93. So i went there today just to see if it would run any better and it did. But i did use some octane booster aswell.

AAAAAAH!!!!!! That stuttering is called knock.... its basically like taking a jackhammer to your engine.
 
Google search "Pre detonation" "pre ignition" or.. "knock" if you want a technical description.
 
Dont ever put anything lower than 93 in the car