going lean all the sudden

[psi4power]

just installed rc550s and the air/fuel is reading perfect till about 6-6.5 k then all the sudden goes lean and falls on its face. I was tryin to run about 20psi. Runs great till that mark, i was told that the stock heat range plugs could cause too much heat and that condition could happen, im wondering has anybody else had this problem

 

[psi4power]

also when i turn boost back to 16ps and adjust the fuel pressure get the a/f right it runs strong all the way through

 

[Enigma_Man]

What are you using to compensate for the 550 injectors? You need some sort of air-fuel control. Your mod list says something about zietronics air/fuel, is that a gauge, or a controller?

If you don't have any sort of control, my guess is the ECU is causing fuel-cut, because it's still controlling the 550's like it would control the stock 450's, it sees way too much airflow, and bails on ya. If that is the case, your car is going to be running very rich, won't be any faster, and will still have fuel cut.

When it "falls on its face" does it just run lean? Or does the car actually feel like it's trying to stop, slams you forward into the seatbelt?

-Jesse

 

[psi4power]

its the gauge from road race. No type of safc yet i plan on it but guess im lookin for a quick fix, it basically cuts out and throws you forward, just totally cuts out for that second it happens. It does still run a lil rich im getting .94 -.96 from my o2 sensor

 

[KRAZYKOREAN]

Yeah you need some kind of fuel control to lean it out during the lower rpms and then you need to richen it up on the higher....S afc will be a nice next mod...there really isn't a temporary fix...

 

[CBgst]

Yep that's good ol feul cut. get an afc and you should be set.

 

[brads]

If you want a cheaper solution than the AFC, the MAF translator will allow you to adjust for the bigger injectors, and give you a better flowing intake. Or for supercheap, pulling some honeycombs out of your MAF will lean the car out a little, to compensate for the injectors, and get around fuel cut. Without a way to watch knock though, you need to be VERY careful when playing with your cars tuning. Dataloggers are a good thing.

Brad

Originally posted by psi4power
its the gauge from road race. No type of safc yet i plan on it but guess im lookin for a quick fix, it basically cuts out and throws you forward, just totally cuts out for that second it happens. It does still run a lil rich im getting .94 -.96 from my o2 sensor

 

[KRAZYKOREAN]

Hmm that not really a cheaper solution...the maf off ebay is going around 45-75 bucks and the maf translator is 200 bucks..then you need a new intake pipe and a new filter..so actually its more expensive...removing some honey combs is not a good Idea..IMO like I said before just do it right and get a afc I seen this baby for like as low as a 240 used...new and used work the same...Maf Translator is dope...but will cost more...

 

[brads]

Afc simply lowers measured airflow, just like a glorified honeycomb removal. Is the afc a little more tunable? Yes. But this response is to a person who is running 550s with the stock fuel system. If he can't afford to do it correctly right now, the honeycombs, if done carefully like I said, will improve his situation.

If he could afford to do it correctly, the right solution wouldnt be with an AFC. AFC is ok for 1G guys, sucks for 2G guys, but this has been explained on this board a million times already. So if you havent gotten it yet, no point in explaining it again.

When you are figuring out pricing, add that he can sell his stock MAF. And if he had a K&N for it, he could sell that too to offset the cost of the new air filter. The intake pipe isnt all that much, and is something people upgrade anyhow. I expect with a little ingenuity, you could still use the stock intake pipe if you wanted. So the cost wouldnt be too bad, and for it you get more than just an electronic bandaid, which is all the AFC is. Much better deal than the AFC.

Brad

 

[nine5raptor]

i used the stock pipe with my maft.