Running extremely lean (or maybe rich?)

[mikevar94]

So here's the deal, to make a long story short, I bought a 99 gsx and the stock turbo blew after a month. I replaced the turbo with a small 16g and a tubular manifold. Before when I had the old turbo I noticed when I gave the car gas while decelerating the rpms would drop and the car would sometimes die. Idled incredibly rough and smells like its running rich/lean. Well that's what people tell me. It's also awful on gas. Now that the new turbo is on with the tubular manifold and not the cast one I can see the manifold starting to glow red hot just from idle...probably did that before but couldn't see the glow and that's probably what blew the turbo I'm guessing? Any its at a shop now and they checked the timing, anything fuel related and apparently everything checks to be in good shape. What do I look at now? Mass air flow maybe? Vacuum leaks?

 

[bryanwheat]

Check for boost leaks and make sure that the bov is recirculated.

 

[rydereclipse]

I am sure someone with far more knowledge chime in, but here's my 2 cents.

You have a couple separate issues it sounds like. First, you said the old turbo caused the rpm drop and die, is the new turbo doing the same thing? How much boost are you running, have you done a BLT?

Second, the manifold is of course going to get hot but shouldn't be glowing red just at idle, could be your leaning out, what kind of EGT's do you have? I would get a wideband or a logger and find out the AFR's immediately.

If you are smelling gas, check the injector seals, the fuel rail connections...anything that fuel travels in, the fuel leak/smell would be my top priority.

These are just the things I would do in your situation, YMMV.

 

[mikevar94]

Yeah the rpms still drop with the new turbo. The shop said everything fuel related is I'm check but I don't know exactly what they looked at. You don't think it could be a faulty maf sensor? Oh and also they grabbed an ecu from the junk yard and out that in and it made no difference

 

[troubleshoot]

Fuel pressure regulator maybe? After I installed a walbro 255 and bigger injectors I had the same problem minus the fuel smell. Something is definitely leaking fuel. Like stated above, check injector o rings, fuel rail, etc for leaks.

 

[casperfast]

is your blow off valve recirculated? or does it vent to atmosphere? (the thingy that makes the loud air sound when you shift or let off the gas when boosting) t needs to be connected to the air inlet of the turbo. if not it will run rich, and stall and sputter and can die.

 

[mikevar94]

Yeah it's recirculated. And the smell isn't necessarily a fuel smell..it's just that specific smell when something's running too rich/lean. I don't really know to explain it. The car still has the stock exhaust systems and the tips are all warped and burnt looking.

 

[casperfast]

that could be a bad cat, bad or lazt o2 sensor or even a really dirty mass air flow sensor