Dropping off lean WOT problem

[steve-o_95_GST]

On my friends 95 GSX, he has a problem of running lean during WOT pulls over 3rd gear. His car runs fine at idle, cruise, and half throttle accel. We have tried everything that I can think of. We have replaced his fuel pump with a 190, complete ss 6 an fuel line/inline fuel filter, tank to fuel rail, swapped injectors, fpr, mas, map sensor more things that I cant think of right now. We did boost leak tests and found one a the tb and injector seals, fixed the one at the tb and will be ordering the seals tonight. He is running factory injectors and an evo III 16g at 10 psi. All of my ideas are exhausted except for a fuel pump re-wire which cant hurt but I dont think it will solve the problem. Can anyone offer up any ideas?

 

[drewvr4]

the answer is simple, fule management...a safc, aem, or dsmlink

Fuel pump and Injectors are what make it capable to push fuel, a fpr allows the amount of fuel to run threw the rail, but only fuel management will alow the injectors to put more fuel into the car

 

[andymoraitis]

What I'd like to know is how you've both determined that it's running lean. Are you logging it or just guessing. If it's knocking, I'd like to see some type of timing log. That turbo should be able to run 15-16 psi on stock injectors with a 190 before leaning out provided everything else is in shape. 10 psi should be a joke.

Also, boost leaks make you run rich, not lean. A better idea would be to pull the plugs, take pictures and post those or simply describe how they look.

Get back to us with more information,

Andy

 

[steve-o_95_GST]

I used my datalogger on a few runs and the o2 voltages drops past .30 and timing goes to 0 the car also looses power. The plugs are brand new ngk bpr6es and look greyish with a tint of brown (I can get pics of them tonight). We also did a compression test since he had plugs out and it was perfect all the way across.

 

[donmagicjuan]

One possible cause is that manifold pressure is not being applied to the fuel pressure regulator. Check to see if the vacuum line is connected to the regulator first. If it is, you can check the operation of the fuel pressure solenoid by pulling off the vacuum line while the car is idling at normal operating temperature. If you don't feel a vacuum on the line when you put your finger over the end of it, the solenoid is malfunctioning.

 

[MrBoxx]

If O2 voltages are dropping halfway through a WOT run, the front O2 sensor may be starting to die. This is the case in my car and the DSMLink forum diagnosed it when I posted my log there.

 

[dsmgrimreaper]

sell it cheap ill buy it cheap that will fix all your problems