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Over Fueling Problem


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hi everyone i have a 1995 r33 gtst, only things done are an apexi filter, full 3'' turbo back (no cat), and a fmic, hks blow-off..... so car idles fine and cruises ok but once you start pushing on the gas pedal my afr's (its a narrow band) just start droppping, to as low as 10 to 1 and as soon as i hit 5 psi i hit fuel cut. So my buddy has nistune and we plugged his laptop into my car and watch what its doing and everything looks normal expect for my maf and injector which under any kind of load max out, so we thought the maf was defective and i sourced a compatible maf and install it.... no different, try removing the blow-off and installed the factory one..... no difference, checked all the piping for leaks.... all is tight and no leaks at present time.... has anyone one had this problem or something similar? the motor is a r33 series 2 motor.

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If those are your only mods then it wouldn't be your MAF, unless you're talking about your AFM? MAF is just used for the stock boost gauge. But have you checked your fuel pressure regulator?

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Try swapping the fpr with a known working one. Probably not the cause, but best way to eliminate problems is to start with the cheapest solutions and work your way up

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I had an identical problem with my 33 a few years ago. Turned out to be a boost leak in one of the silicon hoses. Looked 4 times before i found it. It was a split located in a spot where I had to pull the pipe out to see it :verymad:

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At what boost/prm is the afm hitting 5.1v?

it depends on the rpm its anywhere between 2-4k and i cant get pass 5 psi

I had an identical problem with my 33 a few years ago. Turned out to be a boost leak in one of the silicon hoses. Looked 4 times before i found it. It was a split located in a spot where I had to pull the pipe out to see it :verymad:

like you said it could be a boost leak and it could be one of the silicon couplers i guess i could recheck them again, all the silicon couplers are new

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similar issue to mine, seem to be hitting R&R. Car seems flat through the rev range even though its on standard boost (confirmed by an aftermarket boost gauge) reset ecu, car came alive again, after a couple of days was back to its normal self

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