safc i'm lean when lifting off throttle

[pSimytSi]

ok well I'll start with saying I'm fairly new to all this turbo and dsm talk.. I hope you's take the time to read and reply with your knowledge.

A few days ago I was given a great deal buying my friends 95 talon awd so there was no way I was letting it go to anyone else. I bought it within minutes of him offering it to me.

How it all came about and the problems I'm facing. My friend gets his car back from a distant tuning shop after they installed a new engine and other misc. parts. He gets about 200mi. into the break in and believes it isn't running like it should so he brings it to a local engine shop for a checkup. A month goes by before they call him up with the news they didn't find anything wrong but now the car starts up sputters spits smoke and dies. They said they could do no more but he could pick it up free of charge. It was then parked in his garage for a few weeks until he lost his job and offered to sell it to me for a price I couldn't resist.

Before this car even made it to my garage I was on this site as well as others using the search reading page after page of problems and possible fixes. Searching here did wonders, within the first 10 mins of having the car I found the engine shop either reset or just plain ####ed up his safc settings. I did the setup then set the ne points similar to what some posts and rre recommened for a similiar set up car. First turn of the key it started and idled by itself although a bit ruff with rpms going from 600-2200 and the exhaust smelling like fuel.

I tweaked the numbers a bit but I'm now stuck with a few other problems. Cold start up is still a bit ruff with the rpms going up and down from 600-2200 then when warmed it levels steady around 2000 which I believe is pretty high. It does have a fully built motor though so should it idle that high?

The afr jumps from about 14.2-15.2 on idle so after gaining some confidence that this was good I took it on some short test rides. The afr went from the lowest I saw 10.2 on a rather hard pull reaching full boost 15psi but mainly kept an 11.x-12.x during boost which I believe to be decent numbers?

The 2 biggest problems now I believe one happens around full boost I think it was in 4th gear and I started around 3k rpms got into it and around 5-6k rpms it began to sputter/cut out. I lifted it instantly went back to normal so I got back into it and it pulled fine to 6-7k when I let back off. Tried this a second time and it did the same thing again.

The second problem when lifting 100% off of the throttle I noticed the afr gauge read only 3 red dashes and the l.e.d mark was at the leanest reading of 18. As soon as giving it throttle again it dropped back to 14.x. I found it does this at every rpm above 2500 if I'm in the throttle and let off completly it bounces up to 16.x 17.x and then goes to red dashes until either the rpms drop below 2500 or I push the throttle again both which instantly brings it back to normal. I hope this is something with the safc settings and the stuttering perhaps just boost leak, ignition, or the fuel pump/filter/injectors?

Here's some of the mods it's supposed to have for reference. 255lph and 550cc injectors but no fpr. 1g bov. tial wastegate. evo3 16g. large greddy fmic. cold air intake. stg 2 2.0l with I believe 9.5 compression. I can post what numbers are in the safc, I've never touched one so I have no idea how much better it can be or if they're even close to good. They're only set to get a decent afr, I have no logger or wide band 02 as of now.

I'm trying not to drive it any more until the second problem is fixed and it won't be boosting until the first one's fixed. It really deserves experienced hands but can you guys help me out until I upgrade to bigger injectors and dsmlink?

 

[JayRolla]

When you lift off the throttle the ecu should richen it up real quick then it will go lean, when your decelerating. That is normal. Have you gotten your fuel trims to 100%? When you say it spudders, what is the afr? Sounds like your running rich there. Try to get the car to run 10.7-10.9 the whole way through boost and see how it does. Also make sure you have no boost leaks.

 

[pSimytSi]

"When you say it spudders, what is the afr?"

That's a good question. I wish I would have looked at that but it happens real fast and I instantly let off as quick as my reaction could let off. I don't think it spudderd more than 3-5 times within probably 1 second before lifting. Will maybe take it for another ride and try to see what happens.

As for it going that lean on decel that's normal? How about the 2000rpm idle? I've yet to figure out how to check or set my fuel trim. I'll have to search that again.

Thank You already!


I'm adding an edit here: As for it being normal to go 18+ lean on decel, if I'm around 2500 rpms or under and let off or when I let off once it drops to around 2500 the afr remains/regains 14.x..?

 

[VancTalonAWD]

There are some really great articles in the tech section on tuning with a SAFC that I found really helpful when I had mine. But before you get to any serious tuning you really need to get an adjustable FPR and a data logger. With a 255 pump the stock FPR will be overrun and without a data logger you can't see your fuel trims or timing, which are very important for tuning. I picked up a data logger from ebay for pretty cheap and I'm pretty sure many of the supporting vendors have them.

Also you really don't need bigger injectors if you're running a 16G. I run 580 injectors with an EvoIII 16G at 20psi and reach no more then 75% duty cycle. On a SFAC larger injectors will just make tuning that much harder because of the large corrections you will need to make resulting in abnormally high timing advance.

Excellent SFAC Tuning Guide
http://www.dsmtuners.com/forums/articles-tuning-ecu/58403-definitive-piggyback-tuning-guide.html

 

[JayRolla]

Your going back to 14.7 at decel when low rpms come around because your idle is too high. Adjust the idle screw back and if it dont go down then adjust the sensor on top the the TB that pushes on throttle cable. Sounds like its holding the throttle plate open a little.

 

[3tcpower]

The idling issue you described sounds a little like a boost leak. I resolved mine a little be disconnecting and reconnecting the IC piping and inspecting the BISS screw. Not sure which fixed it, but its fixed

 

[pSimytSi]

The idling issue you described sounds a little like a boost leak. I resolved mine a little be disconnecting and reconnecting the IC piping and inspecting the BISS screw. Not sure which fixed it, but its fixed

I have tomorrow off so I may try and fab up one of them boost leak things from another thread on here. Do you mean the rpm variation when first starting up or the high idle? It has been known to blow off the IC piping actually just yesterday it blew off the hose from the turbo to the wastegate. I'm planning on getting a bunch of clamps so I can double clamp everything possible.

 

[matthewdesigns]

Have you gotten your fuel trims to 100%?

OP, Jayrolla's advice to get a handle on fuel trim is important, but you are shooting for "0" as normal with your 2g, not "100".

Read this and this to get a handle on safc operation and settings. And anything written here on Tuners by spyderturbo007 is pretty much gold regarding safc tuning.

You definitely need to build that boost leak tester, and if you have an air compressor then it will be much better than a bike pump. If you are blowing off couplers then you probably have leaks around the engine bay. And don't forget the soapy water...don't just trust your ears. If you are going to reclamp everything, then find some t-bolt clamps. They are much stronger and more reliable than hose clamps.

 

[3tcpower]

Both high idle and the erratic idle. Mine behaved a little better after warm up before I did the hose checking. Now it idles alot better.