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hey guys,

sorry to keep askin sooo many questions but my cars always havin probs......

well i recently got my car back an ive finally run my car in, but wen i go to floor it my car chugs an loses power above 5000rpm!

i took it back out to my mechanic 2day, an he checked the coils, afm's, the cam/crank angle sensor (cant remember if he said cam or crank) an im pretty sure he checked the ignitor as well, its none of the above......so he thought it mite be my fuel system, he put it on the dyno an he said the car is runnin rich so its not the fuel pump, im pretty sure he also said that he swapped my computer over with another one an the prob was still there! i mentioned the fuel filter an he said he'l swap it over with a new one but doesnt think that'l make much difference.....

does anyone no WTF is wrong??? any ideas would be greatly appreciated.

Thanks in advanced!

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I dont know if the 200sx's are like the skylines but if you have a few bolton mods and up the boost they go run really rich and yea when giving it a boot it feels like crap.

Rich and retard is the only thing i got ??? what are your ait/fuel ratios like

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It can be a number of things, and like mentioned above timing can cause this.

Has it got an aftermarket ECU?

What is the fuel pressure?

What is the fuel flow volume?

Is the air cleaner restricted in anyway?

Do you have a blocked exhaust?

Is there a vacum leak?

How rich was it actually running,? If to rich it might be flooding and thus causing it to miss.

Some of these things that are easy to check yourself.

Tell us how you go?

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Without more info, my guess is:

boost cut (yes this doesnt exist but its easy to explain it this way)

lower the boost a touch and try again, continue to lower until the problem is fixed. once you have done that, go and buy a SAFC at the very least so you can do some light tuning and return the boost to a higher setting.

I had the same drama in the skidline some time back as it was doing the same thing when under load.

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Its running stock boost at the moment, its got a 3 1/2in kakimoto cat back exhaust, x-force dumps, garrett gt2860r turbos, apexi pods an rebuilt bottom end....

jus spoke to my mechanic, he said he's stuck on another pair of afm's, new pair of coils, another ecu, checked the ignitor, when he had it on the dyno he said it was runnin fine up until 5000rpm then it would run real rich.....

keep the suggestions comin fellas....still not fixed :)

thanks.

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when he had it on the dyno he said it was runnin fine up until 5000rpm then it would run real rich.....

So from what i can gather its running to rich and this could be causing the problem.

It has been mentioned before but i didnt see an answer, sorry if i missed it.

But has the o2 sensor been changed or checked?

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Yeh, MORE INFO!

Check the Crank Angle Sensor.

Connections and wiring(look for cracks, exposed wires, etc)

Could be your engine is just shit! What engine have you got(s14 sr20 i assume)? You sure it's running rich and not leaning out? I don't see injectors or pump or regulator on that mod list.

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Could be your engine is just shit! What engine have you got(s14 sr20 i assume)? You sure it's running rich and not leaning out? I don't see injectors or pump or regulator on that mod list.

He's got a basically stock RB26 in an R32 GT-R that's just been rebuilt, he had the S14 before the R32

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yeh i asked him bout my 02 sensors an he said they should b alrite, not sure if he checked them tho...

yeh pretty sure he checked the crank angle sensor.....

nah no more s14 sr20....now an r32 rb26... i hope its not a shit engine, i jus spent bout $12,000 rebuildin it!!!

yeh its runnin rich kos he had it on the dyno yesterday arvo, still got stock injectors an supposedly ive got a bosch fuel pump (but cant garauntee that, jus what the previos owner told me)

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my mechanic said he's checked everythin an now wants to get an auto electrician in to check all the wiring kos he thinks the voltage is droppin somewhere, but im thinkin that i should take JaiJai opinion and get a second opinion.

does anyone think theres a chance that it could be boost creep??? was thinkin bout gettin a fuel cut defender.....

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Why a fuel cut defender? If it was cutting fuel then it would be a aggresive misfire not just a loss of power. Come to think of it, I dont even think the GTR's have any form of fuel cut for "overboosting" anyway... certainly not at the boost levels you are talking about anyway.

You have said loses power, not ignition cut/misfire so its not an ignition problem.

The o2 sensor is only used on light throttle cruising, at WOT it isnt being used.

My money is on the fact you have upgraded to turbos that can flow a substantial more amount of air than the factory ones, and the ECU isnt liking it one bit.

You really should be running an aftermarket ECU for the modifications you have if you want it to last (or at least find someone that can remap the standard one) or else you will end up with a shit engine.

Edited by Amaru
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oh ok, i also forgot to mention before that when i picked up my car yesterday my mechanic said the air fuel ratios were fine until it hit 5000rpm then it would run rich....

plus he told me that i have a "trial" ecu fitted....if thats any help to anyone...

he also said, if there is a voltage problem theres chance it could be my alarm.....

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