A/F Correction

[HolyCrapItsFast]

Yeah you need a re-tune. That's to rich.

It looks like it is rich across the board. You could reduce your entire MAF scale about 3% will bring it closer to where you were but even 10.9 is to unnecessarily rich IMO.

 

[Spamby]

Well, my fuel parts arrived finally. I ordered a factory FPR and installed it yesterday. Took it for a drive without an ecu reset and noticed a bit peppier response. Fuel trims took a downturn to about 14.8 positive. This is from 18 positive, well actually 20 but that's likely because I've only got half of my CAI on right now, went from 18 to 20-21 after I half assed my CAI.
Anyhow, fuel trims at that cruise range seem to settle at 14.8. However, I've noticed the fuel trims hunting all over the place and spiking as high as 25 positive.

I pulled over and reset the ecu and continued a drive. Fuel trims at cruise hit 11.5 positive and stayed there. She would tick up from zero in increments of 2/10ths every second for about a half mile until it stopped dead at 11.5.

I'll drive it today some more to see if they continue to stay at that range or progress up. I'm cautiously optimistic.
Also, I'll put my CAI back together and see if that doesn't make a change of two or three points.

So if it stays at 11.5 and me putting that CAI back together can effect a 2 or 3 percent change, I'd be at 8 or nine percent positive and basically I'd be tons happier. My gathering is that with the funky FPR setup, a GR within 10% is acceptable.

Fingers crossed.

 

[Spamby]

No go. LTFT back up to +18. Stumble is still prevelant at 4-5k rpms wot 3-5 gear. Car bucks back and forth. Though not as bad as before and she feels like there is more power in that stumble area and pulls through it faster. ( used to kind of hit a brick wall there)

Going to pull the fuel pump next weekend. Perhaps an o ring is missing or not seated or the filter is dirty?

 

[welaish]

[MENTION=1507]Spamby[/MENTION] That was expected. after I installed the FPR and the Trims went back to negative values. I realized it goes to Positive correction on 3600-4000 instead the famous 2800-3200 but no bogging or hesitation, the range is smaller. So I decided to hit the Compensation table and tune it out and this is how it looked like:
https://docs.google.com/file/d/0B6zn_kRV08vAWGRScWs2dHR1RVU/edit

Now it is amazing and the LTFT is almost Zero in all RPM ranges between -2.3 and +0.70

 

[qht_sti]

In my case the issue came up about two weeks after being tuned with a walbro fp , DW 850 injectors and meth injection. I initially suspected the new injectors and changing back to the stock injectors and map didn't fix the issue.[/QUOTE]

Thanks [MENTION=4684]welaish[/MENTION] for your thread. Changing the FPR also sorted out my high fuel trims and 3000 rpm stumble.

This is how my fuel trims and leaning view looked with the stock FPR.

learning view

 

[welaish]

[MENTION=4963]qht_sti[/MENTION] great that it worked out for you. do you have plot after the FPR. did you tune it? or you just installed and all went back to normal? also which FPR did you install?

 

[qht_sti]

I installed an AEM adjustable FPR and set the fuel pressure to the same level as the stock FPR. I did have to adjust the CL maf scaling by a few percentages to get it below 1% for all ranges.
My wideband AFR readings were spot on for the OL fueling targets.

 

[Spamby]

Holy monkey I think I just found my problem!!!!!!!!

One of the fuel lines within the pump housing was not clipped in.

It's the black line with an o ring and a clip type connection. This mfer was not clipped in and sitting cockeyed. Like way the hell off.

Damn Cobb tuning and a fuck up when they installed the pump prior to tuning. Shit happens so no hard feelings to Cobb but what a dumb elementary thing to do?! It's either clipped in or not and very evident if it's not.

Now to put it back together and do some logging!

 

[Spamby]

That is it.
I didn't do an ECU reset I wanted to see what she'd do.
Idle AF learned dropped to 1.6 positive from 7-9 positive.
AF correction at cruise has dropped 2.5 full points from a positive 21.5. So she's definitely learning.
WOT pull now is smooth all the way the red without any hiccups or stumbles.
Everything is looking better and the car is definitely improving in the performance area.
That's it for me. Time to go have beers!

 

[welaish]

[MENTION=1507]Spamby[/MENTION] thats super. Thanks for your help all the way. Why it was stumbling in this area only!? Or you had driving issue in a whole range?

 

[Spamby]

[MENTION=1507]Spamby[/MENTION] thats super. Thanks for your help all the way. Why it was stumbling in this area only!? Or you had driving issue in a whole range?

And thank you for help, as well.
The car would buck and snort under WOT in the 4-5k rpm range only. Under part throttle it never did. Admittedly I rarely ever stab the pedal to the floor and almost never above 5k so I really didn't notice that area much.
It most definitely was because of fuel pressure or flow. I guess when the fuel demand was high, that connection being loose caused it to not have the right pressure or flow that the engine demanded at that load.
Logs suggested a vacuum leak but they were odd or randomly high fuel trims in weird areas. The trims would rise and fall all over the place but would never show a real pattern or consistency indicative of a boost/vacuum leak.
Another thing I noticed was that I never had residual pressure in the fuel system. I could pop any fuel fitting loose and only a dribble of fuel would come out.
Also, cranking times were extended a bit longer than normal. Not excessively but it would take a few more revolutions for the engine to fire. However, if the engine were hot and especially in summer temps, and I had just stopped to get gas or run into the market for a minute, I would notice the engine would not fire without having to prime the system two or three times. If I didn't prime the system, it would crank for longer than 10 seconds before it would fire when the engine was hot.
Over time it seemed to worsen as that hose was probably working its way out more and more.
I did a hard pull from 3rd to 5th hitting about 100 mph and she pulled flawlessly and like a damn freight train.

 

[welaish]

Thats good man. Perfect! Which hose was loose in the engine bay?

Well thats my learning view now. It looks Super and the correction maximum I am seeing is 11%-14% instantly.

I am wondering now was it really the FPR or something else.

 

[welaish]

Sorry you already mention pump hosing. Ignore

 

[Spamby]

Thats good man. Perfect! Which hose was loose in the engine bay?

http://tapatalk.imageshack.com/v2/15/02/07/8a28a1bba5ae83d06c5f8324fe5dd854.jpg

Well thats my learning view now. It looks Super and the correction maximum I am seeing is 11%-14% instantly.

I am wondering now was it really the FPR or something else.

Well, in your case I think it probably was the FPR. Since yours wasn't holding pressure correctly and mine wasn't either, symptoms were similar.
We'll see how low my AF learning C drops.

 

[welaish]

[MENTION=1507]Spamby[/MENTION] how is your trims now?

 

[Spamby]

[MENTION=1507]Spamby[/MENTION] how is your trims now?

[MENTION=4684]welaish[/MENTION]

Haven't checked them in a while but last I saw it was down to +12%.
The weather has been unstable lately going from 70* F to 5* so it's difficult to get a consistent reading.
Yesterday the temps were 35*, today will be 60* and tomorrow will be 25*.. Fahrenheit. See what I'm working with ? Lol

 

[HolyCrapItsFast]

@welaish

Haven't checked them in a while but last I saw it was down to +12%.
The weather has been unstable lately going from 70* F to 5* so it's difficult to get a consistent reading.
Yesterday the temps were 35*, today will be 60* and tomorrow will be 25*.. Fahrenheit. See what I'm working with ? Lol

That's still to much. I could fix this with one log :lol:

Go ahead... Test me. :tup:

 

[Spamby]

That's still to much. I could fix this with one log :lol:

Go ahead... Test me. :tup:

I would love to but my map is locked.

I looked at it tonight and she is at 10.7 while cruising.
Cobb notes that 8% is norm and a touch worse given the GR's FPR.
I'd love to replace the FPR and due a retune

 

[nlytnone]

I too am running too lean AFR values running 11 low to 20 high but at cruise control 14.8. will be changing the FPR off my blown engine see if that will help. I think the other is when I but the car It came with the K&N Typhoon, and a GReddy BOV type RS which I think will replace with stock BPV of the old motor. if it is not the FPR then im screwed ive tried everything else and read tons of forms from all the other sites but cant but nothing that says what is the culprit When I bought her she cam with the K&N Typhoon intake, the exhaust is CBE and a GReddy BOV type which I am fixing to switch back to the original, when the replacement motor came for the swap it had ULH and no tune before I ruined the first engine and no stock parts to put back on for the new motor. So basically stuck with these parts on the car with no protuneand reading everything I have has got me very worried cant afford 4gran on another motor.

 

[HolyCrapItsFast]

I too am running too lean AFR values running 11 low to 20 high but at cruise control 14.8. will be changing the FPR off my blown engine see if that will help. I think the other is when I but the car It came with the K&N Typhoon, and a GReddy BOV type RS which I think will replace with stock BPV of the old motor. if it is not the FPR then im screwed ive tried everything else and read tons of forms from all the other sites but cant but nothing that says what is the culprit When I bought her she cam with the K&N Typhoon intake, the exhaust is CBE and a GReddy BOV type which I am fixing to switch back to the original, when the replacement motor came for the swap it had ULH and no tune before I ruined the first engine and no stock parts to put back on for the new motor. So basically stuck with these parts on the car with no protuneand reading everything I have has got me very worried cant afford 4gran on another motor.

Are you able to give us a log?

I know you say you looked at everything but I will list the possible causes for you just one more time for you to go over again, Possibly you can go through these steps again and find something you missed. High fuel trims can be caused by the following...

1. The first and most common cause is a leak in the system. The best way to check for these is a boost leak test. Also a can of carburetor cleaner often works. Spray it around all the hose connections and gaskets and listen for changes in idle. Re-tighten all clamps and wire tie your vacuum hoses. Check the gasket around the BPV.

2. Bad fuel pressure regulator.

3. Dirty fuel filter. This is located in the fuel tank. You can clean these but I recommend just replacing it.

4. Clogged fuel line.

5. Faulty PCV Valve

6. Dirty injectors. A simple injector cleaner will help here

7. Bad fuel pump. I recommend replacing this with at least a walbro 255 or better pump regardless.

8. Dirty air filter.

9. Bad gas.

10. Faulty AVCS mechanisms.

11. Modifications with out a tune like exhaust and intake.

Once you have exhausted every scenario, then you can look at tuning as the cause. Keep in mind that we offer complimentary e-tunes to paid members so the cost of a tune should not be one of your concerns right now. I am more interested in seeing you fix your issue rather than blow another motor. So give all of that another check.