Over Fueling Problem

[tuned_nismo]

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.

[Hanaldo]

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?

[tuned_nismo]

yes im talking about afm, i've checked the line going to the fpr and its good, thats the only thing i've check to the fpr

[Hanaldo]

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

[JonnoHR31]

narrowband doesnt tell you afr's, ignore it

sounds like afm wiring

[Adriano]

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

[hr31gts]

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

[tuned_nismo]

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

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

[hr31gts]

specifically, I would check the hoses too mate, they can be hard to see

[tuned_nismo]

i had my car hooked up to my buddies nistune looked at what was going on..... he send we a screen shot......

[tuned_nismo]

bump

[DVS JEZ]

get a programmable ECU and tune it out

[TUF250]

how do you check afm wiring? can you test voltages at idle to work if its ok? would be interested in a description of how to test if the afm is working, having a similar issue in mine

[DVS JEZ]

have you tried the basics? what makes you think AFM is at fault?

[TUF250]

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

[DVS JEZ]

but have you checked anything else, like knock sensors, ignition timing

[tuned_nismo]

i had my buddies nistune hooked up and watch all the sensors and everything was fine the only things were the afm and the injectors maxing out

[JonnoHR31]

sounds like afm wiring

[tuned_nismo]

ok well if you guys think its the afm wiring, does anyone have wiring diagrams, and trouble shooting charts to test, the afm on my car is the 3 pin on