Most of you are probably familiar with my quest to get me car running correctly.
Well, proud to sayI have the motor back in for the second time, and everything is running great.
Except;

When I get on the gas, at about 90% throttle, the car goes lean... very lean . However, if I keep the throttle around 75%, then it stays mildly rich, which is better than lean.

I havn't tuned with the s-AFC yet, I plan to, just curious what would cause that.

Thanks for the help, and if you need any more information let me know.

-Brandon

prolly your regulator. Mine does that cause I hate my regulator and it hates me. Check your fuel pressure. Could also be a bad fuel pump clogged filter or too small injectors

Originally posted by brokenrodguy
prolly your regulator. Mine does that cause I hate my regulator and it hates me. Check your fuel pressure. Could also be a bad fuel pump clogged filter or too small injectors

I might theorize that your headwork is intended for more top end power. Under part throttle, you mix it up just about right, but at WOT, the head is flowing much more air than the fuel system can handle. :shrug

I'm far from being an expert, but I'm thinking the SAFC won't allow you to richen things up, so you might step up to some 22lb injcectors and lean things out down low.

Asking the experts here, am I on target?

Personally, I think I do alright in the top end, but my bottom end (<4000rpm) is severely rich. After a thorough washing, my rear clip (and even rear wheels) gets a nice, thick coat of soot. Gotta get that Zt-2 finished and complete the MS install as well. Similar issue, methinks.

So much to do and I don' wanna. (It's going to be over 112* here tomorrow.) /pout

Originally posted by bzoss
Most of you are probably familiar with my quest to get me car running correctly. Well, proud to sayI have the motor back in for the second time, and everything is running great. Except; When I get on the gas, at about 90% throttle, the car goes lean... very lean . However, if I keep the throttle around 75%, then it stays mildly rich, which is better than lean. I havn't tuned with the s-AFC yet, I plan to, just curious what would cause that. Thanks for the help, and if you need any more information let me know. -Brandon

How do you know it is going lean? You have a wideband or are you just using a egt and the blinky light from a autobeater gauge?

On my techedge @ about 85-99 % throttle my car stays in good a/f ratio numbers, but my egt skyrockets. I think this is due to the timing advance that occurs from partial throttle. *someone please confirm this*

SAFC is a dirty hack and you should get rid of it. It is pretty much useless unless your running some large injectors and a sfmu and need to lean them out to get it to idle correctly. Some people claim that they have used it to 'fine tune' thier fuel curve, but I don't think that thing really does any good. I had it for years and can honestly tell you it did not really help that much if any at all.

I have used the SAFC to fine tune the Fuel curve on the dino, and it does quite well actually.
I am very impressed with its performance.

I figure that with the port work, etc. I am pulling in too much air for the ride to compensate, so I am going to just dino her when she is fully broke in, and see what I can do with the AFC and then go form there.