Im having a stuttering problem in first gear and a/f problems. I have 47# injectors, 255lph fuel pump and a 2 bar map. According to my tuner, whom i trust, the a/f should be floating around 14.7 at idle even before a tune. unfortunately its sitting at 10 and no matter how much fuel he removes its still stays in the 10/11 area. The tuner stated that the stuttering could be due to all the fuel he's removed at idle. WHat could be happening here?

info: 4.7l, 08 intake, t60-1 turbo, 38mm wastegate w/ 7# spring, 47# injectors, 255lph pump.....no known vacuum leaks, no boost leaks.....

im at wits end here ha any suggestions would be great!

 

do you have a rising rate adjustable fuel pressure regulator? if so, what is your base pressure set to?

You are running real rich if you're sitting at 10. This is probably because your injectors are dumping too much fuel before boost. A rising rate adjustable FPR increases pressure when boost is seen. (Usually a 1:1 ratio.)
Another possibility is that you are over running your current FPR with the 255lph.

OR your injectors are on full duty cycles, and thats a tuner issue. You could post some logs, and we could take a look at them. (you are logging right?)

 

I have nothing to log w. I'm going to install a fuel pressure gauge to see what pressure I'm working and i do have a fuel regulator just not installed. I'm using a sct and hemifever for the tune and he has actually leaned it out according to him A LOT and im still super rich.

 

Also, I have to buy plugs...what's the best for a turbo'd 4.7l in ur opinion and what rising rate fuel regulator would work best or will one of the universal ones off eBay work fine? The one I have isn't a rising rate one.

 

Im supposed to get my turbo back from the shop this week. Then, tuning is all I got left to finish. I really hope you get it down by then =D

 

Remme, here's the one I use.

http://aeromotiveinc.com/products-pa...***-regulator/

For turbo cars, NGK-Rs are just fine. I run BPR7ES plugs in the race car. Nothing special, just copper plugs at $2 each. They work just fine with the MSD DIS II ignition.

If you are on a budget, when you get the Aeromotive fuel pressure regulator, you can remove the 1/8th inch NPT plug and install a mechanical fuel pressure gauge. At least you would be able to determine your base fuel pressure and set it accordingly. I'm suprised your tuner wasn't asking these questions before trying to remove fuel from the curve.

 

He did mention the fuel pressure. Do you think my injectors are too large? 47# w the 255 pump running between 8 and 10psi?

 

the thing is, injectors can be tuned. if you have larger injectors, you just need a shorter pulse.

I am also using an aeromotive FPR on my eclipse. Fuel lab also makes some good gear.

How is your tuner (Hemifever) tuning without looking at logs? is he just tuning based on AFR?

 

he's been in the game awhile. i gave him the a/f, boost or vaccum at rpm's in incruments of 500 and he's worked with that.

 

Those 47lb injectors are probably rated at 43.5PSI, and your fuel pressure is probably 49PSI, so they're more like 50lb injectors. He obviously hasn't trimmed enough fuel yet.

You could always go standalone, it's nice to plug in your own laptop and make the changes yourself rather than rely on some guy half way across the country.