Thread: running rich

I am having an issue with my car, i can get on it and it will feel good then i can feel it losing power, when this happens the AFR goes from around 11:5 down to the low 10 area, ideas ? i have checked the tps, timing

Need more info than that such as what ecu are you running. You might have a boost leak somewhere if its something that happened all of a sudden as in it was working good before and just started doing it. If its been doing it since the beginning you still might have a boost leak or could be a fuel pressure issue depending on what your ecu is supposed to be running.

im running a calum ecu, it is a blow thru setup, i have rebuilt the motor and finally have enough miles on it, it was tuned before on this same setup, then motor rebuild now it is doing this

im going to make a leak tester in the morning, but wondering if it would be a boost leak, and if it is it would have to be after the mafs since it is blow thru correct ?

Yeah usually it would but it can also cause it to do it even if its before the maf. Its under pressure so especially when you get on it and boost initially builds the pipes pressurize then pressure drops and bleeds out causing a back flow back through the maf. So it can be on either side. If its a 4 bar program on the calum ecu and your running a full 4 bar fuel pressure that might be your issue as well. I had to run my 4 bar 370cc program, 4bar 520cc program and 4 bar 740cc program at about 3.5 bar to keep it from going soo rich when it initially hit boost. After that i had great a/f ratios, initially hitting about 11.9-12.0 at peak torque and then it would richen up to about 11.5:1 throughout the rest of the powerband. Every program every time.

I would check for boost leaks first though to be sure. I had it happen from my tial 51mm vband bov. The o-ring didnt seat correctly and I was getting crazy rich a/f's everywhere in boost. Fixed that and it was good to go.

btw all my setups were blow through, I think that has a lot to do with the reason for having to turn down the fuel pressure as well. I think the maf was getting a higher reading of air volume in blowthrough vs draw through.

think i have found the problem top of the z32 mafs is leaking really bad, what do you guy usually do to fix this ? rtv and a clamp ?

JB weld. It will hold forever and seal it up.

got it all sealed up, hopefully this is the problem, it was leaking pretty bad, now no leaks in the system

sealing the mafs did not help at all, wondering if maybe the BOV is leaking ? it is a TIAL 50mm with a 9psi spring in it, im running 11psi of boost right now wondering if there might not be enough pressure on top of the diaphram

^Not tryin to drift off topic but your youtube videos are fu*king awsome...lol