Loaded

On my 89s4 auto how can you tune out tip in bog on the 89 series?

SYmptom:
dead start full throttle the car lays down on it self it isnt until5000 rpm and 2nd gear and above that the 928 goes nuts.

Or it is just fine froma roll or punch at speed

Its just 1st gear dead stop start....

Now if you pull the throttle back it accelerates MUCHO stronger but full throttle floored accel just stinks.....

As Ernest said last sunday its called tip in.

FLappy funtions and no fault codes etc........

Jim_H

It's not tip in.

Maybe vacuum related?

I'm sure one of the pros will give you some things to chase down.

Loaded

Hey JIm this is what I am describing:
Re the tip in issue, the previous LC-1 data logging that I did with the stock chip (no SharkTuner) showed that upon tip in, the mixture would go lean into the 15's and on occassion 16's. It would come back within about 1-2 seconds but it was noticable in the logs. One time when doing a rolling start at 5 mph in 1st, the AFR actually spiked up to 18 (yes, that lean) before coming back to the high 12's where it mostly remained. But it did that by working its way through the bad fuel map to fields that were more accurate. The lowish - mid RPM, high MAF load fields in the stock chip are way way lean for the blown application so it is lean until you work through those fields as the rpm increases.

Contrast that to what I could see now with the SharkTuner logging from yesterday. With the fuel mapping adjusted, when I hit it, the fuel injection brain is into the same fuel map fields, but now they are providing more fuel in the same low rpm, high MAF load situation. I tried in a few different gears, at a few different RPM points (1500, 1700, 2000, 2500) to induce the lean condition on tip in and it just didn't happen.

I wouldn't do this in normal driving, but I tested 1500 rpm in 5th and the afr actually went immediately too rich ( a tick under 10). Not pretty. That is where I started taking fuel out of the WOT map again to reduce the WOT enrichment.

Just FYI. When you begin your SharkTuning, you tune the idle+cruise map first with the WOT map at zero in all fields (basically no additional enrichment). Then you add WOT enrichment if you can't get enough fuel out of those fields in the idle+cruise map that you hit when you go WOT. What I noticed is that there are many fields in the idle+cruise map that you only hit when you go WOT or near WOT. Just by enriching these specific fields in the idle+cruise map, you almost completely address the tip in issue. I then added a bit of WOT enrichment in the final tuning.

Another suggestion. I was concerned about doing the WOT testing in a lean state, so before I started the WOT testing, I manually made rich the high load area in the idle+cruise fuel map. That was very easy with the SharkTuner as you can manually select a field or a group of fields and add or reduce fuel with the touch of a button on your computer screen.

Jim_H

Your SC'd?? I didn't know. Sounds like tip in in a whole new extreme. My SC's motor doesn't ' lay down on itself ', it knocked/pinged at about 3000 to 3500 r's. Yours is certainly to the extreme side if it lasts up to 5000r's. Mine was also consistent in any gear at 3 - 3500 r's. Are you sure you have good fuel delivery??

I have seen the tuner at work at it is amazing

Loaded

NO NO NO im not SC'd I have a pretty good feel for the performance of my car and I can feel the tip in issue in my N/A car. Thats all. It feels weird like my old Audi after i tweaked it. or my old road runner with vacuum secondary carb.......nail it, drop vacuum and wait for port vacuum to adjust to fuel mixture etc.....I know what I feel i just dont kow how to fix it

ErnestSw

When did you get the Shark Tuner?

Bill Ball

Where'd you get the SharkTuner? An NA car should not be doing this unless something is wrong. Bad injectors, fuel filter, fuel pump, fuel dampners, regulator. Do you have fuel pressure gauge?

Loaded

no was doing research here and found this and reposted it because it describes my issue very well

The fuel pressure gauge read 55 to 63lbs

maybe some techron to help clean injectors? dunno the car sat for about 5 months

Bill Ball

OK, you have no data at all except fuel pressure, which is fine. But you have this seat-of-the-pants belief the car is having tip-in leanness because it is, I guess, not as quick as you think it should be in the low end. Even if you had leanness, there is nothing you can do about it in a tuning sense, short of the SharkTuner, and I would not use that in an NA car. The mixture is LH controlled. Just make sure all the components are OK and you have no vaccum leaks. You have good pressure. Yes, the injectors could be crapped up. If you want to pursue this, do a good tune-up. Usually with bad injectors the car runs like crap (rough idle, etc) too or has hard starting. Same with significant vacuum leaks.

Has someone messed with this car? Have you driven other stock S4s to see how they behave?

Jim_H

Ditto.

khalloudy

check your WOT switch... i bet it is dead (mine has the same problem), but changing it means having to pull the intake

ErnestSw

Jim and I are going to be at Roger's place tomorrow after 10:00. Bring the car over and let's have a look at it.
I'm not sure we're all talking about the same thing when we're referring to the Shark Tuner. You may be referring to an Air Fuel Mixture (AFM) gauge. The Shark Tuner requires a wide band O2 sensor to work.

Bill Ball

Didn't you guys run the Spanner on Loaded's car? WOT switch was OK. Maybe I'm getting some cars mixed up here.

Yeah, if he has a SharkTuner, I want him to being it to my place too!

John Speake

Well, I didn't sell him one !!

Do tell.......

Bill Ball

John, it looks like Loaded was freely quoting from Cameron's reports without indicating so. Rather confused me and others.