Rich fuel trim

[vavJETTAw36]

Alright guys, I've been on this GIAC 93/e85 tune for ~500 (weekend car) miles. This will be my 3rd tune since I bought the car so don't have a good baseline for what trims were before tunes. With each tune I was usually focused on whether boost levels were in check and I never really got a good picture of whether the fuel trims were good.

Since I've been using the giac tune I've noticed my LTFT running on the rich side. Both banks are usually around -11 for additive and around 5 for idle. No codes either. When I run AC, my trims jump up to -20 or so.

Car runs 23psi and has no problem getting there, however, the car feels a bit sluggish with response. This is my first time with stage 3 in the summer so maybe it's just temp (95 degrees) causing the engine to be sluggish)

What are all the possibilities?

Here is a log of a normal commute with a little bit of boost here and there:
https://drive.google.com/open?id=0B2...2hxbUZTNEkxbkk
Sorry it's vcds. Didn't have my eBay cable to run me7logger.


Things ive verified so far:
- So far I've checked fuel pressure. 51 psi idle, 58 with FPR unhooked. Car turned off it jumps to 42 and slowly increases to 51 in 10 minutes time.
Correction: Currently checked the pressure to be out of spec at 56psi/63psi
- Rear 02's completely coded out - Thanks to corradovolksb
- No external boost leaks - Verified up to 15PSI
- replaced at least two leaky check valves
-diverter valves hold tons of vacuum with no leaks
- brand new MAF and have tried flow straightener
- brand new primary oxygen sensors installed.

Other considerations:
- Injectors were verified to flowmatch
- New 2.5 SSAC Exhaust with New catalytic converters put on before this tune

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[Bordom]

Is the negative not indicative of leaner fuel trims?

I was under the assumption that was the case, and positive values indicated rich running

Everything graciously mispelled by Android

[HighPsi(NorCal)]

If the O2 sensors indicate LEAN, the computer adds fuel and generates a POSITIVE fuel trim value. If the O2 sensors are reading RICH, the computer compensates by subtracting fuel and generates a NEGATIVE fuel trim value.

[Devious27t]

What intake are you using? Did your AWE maf come with a flow straightener?


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[vavJETTAw36]

What intake are you using? Did your AWE maf come with a flow straightener?


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Devious, I was only told to buy a 85mm MAF. So I bought an 034 unit with a stock air box adapter. The tune is sold by Emmanuel designs.

The tune (you mentioned it being a copy of one of your cars) calls for the following:
-3 inch downpipes
- Emmanuel custom spec 550cc injectors
- Bosch 044 pump
- 85mm MAF housing
- upgraded inter coolers
- k04 or f21 turbos

http://www.emmanueledesign.com/colle...conversion-kit

I did buy a honeycomb type flow straightener to put in my MAF but the tune doesn't specifically call for it so I didn't use it.


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[Bordom]

If the O2 sensors indicate LEAN, the computer adds fuel and generates a POSITIVE fuel trim value. If the O2 sensors are reading RICH, the computer compensates by subtracting fuel and generates a NEGATIVE fuel trim value.

Ooh, I understand that now. Thanks

Everything graciously mispelled by Android

[vavJETTAw36]

Ooh, I understand that now. Thanks

Everything graciously mispelled by Android

Perfectly described


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[vavJETTAw36]

Got my rear 02s coded out completely including the catalyst control. No changes to the fuel trims. However, i believe I'm having an issue with the DVs they keep sticking open during partial throttle and this may be my issue. I think the problem is deeper than the DV quite possible a n249 issue or the check valve near it.


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[y3ti]

the primary O2s affect fueling. the rears are used to measure your catalytic efficiency (they won't do anything to fuel trims).

[vavJETTAw36]

the primary O2s affect fueling. the rears are used to measure your catalytic efficiency (they won't do anything to fuel trims).

Wrong.

From Bentley manual:

Oxygen sensor control behind the catalytic converter is responsible for final control correction. It is the primary sensor and can override the signal from the oxygen sensor control before the catalytic converter.

Oxygen sensor control behind catalytic converter is superior to oxygen sensor control before catalytic converter and is the primary control. It corrects slight changes in the mixture (i.e. enrichment or thinning) by holding oxygen sensor control before catalytic converter at its highest or lowest point for a specific time (duration). If this time is in the positive range (i.e. 50 ms), mixture is shifted in the -enrich- direction. If this time is in the negative range (i.e. 50 ms), mixture is shifted in the -lean- direction.


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[y3ti]

From Bentley manual...

that's interesting... I've always understood secondaries to be specifically emissions related.

I'll have to look into it some more...

[vavJETTAw36]

that's interesting... I've always understood secondaries to be specifically emissions related.

I'll have to look into it some more...

I think a lot of cars are like this. But in some cars like the b5 s4, the rears play a role in fueling. Damn Germans ;)


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[y3ti]

Damn Germans ;)


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lol, an oxygen sensor that overrides an oxygen sensor... overengineering at its finest.

[vavJETTAw36]

Alright guys I re-verified boost leaks and actually found a couple decent sized ones. Additionally, replaced and gapped my plugs to .025. It seemed to have reduced the trims slightly but still I am having issues. Car holds pressure for way longer now (50 seconds to go from 15psi to 0)


After logging today, LT Mult and LT Idle are:

LT-M: -14, -16
LT-Idle: +1.6, +2.0

I can recreate this everytime now by just cruising in 3000 RPM

[erykv1]

Have you replaced all your internal check valves? (green check valves under intake manifold? verified DV's are good? Spider hose good?

You seem to be having the same issues I have (check my post history for the thread). Symptoms say boost leak, but I cannot for the life of me find it. I've pressure tested the car more than I can count.

Not sure how your car drives, but I've driven with the MAF unplugged for the time being and the trim's seem to be much better. I have a new maf housing on the way with a flow straightener and once I get that in I will report back.

[vavJETTAw36]

Have you replaced all your internal check valves? (green check valves under intake manifold? verified DV's are good? Spider hose good?

You seem to be having the same issues I have (check my post history for the thread). Symptoms say boost leak, but I cannot for the life of me find it. I've pressure tested the car more than I can count.

Not sure how your car drives, but I've driven with the MAF unplugged for the time being and the trim's seem to be much better. I have a new maf housing on the way with a flow straightener and once I get that in I will report back.

Eric, I did check my green valves when all this started. Found one leaky one where the f hose attaches to the hard lines on the fuel rail. Replaces that with no success. Found another leaky one (black one near n249) and swapped that whole cluster of hoses from a working car. Still nothing. This was a couple months ago so I might change the ones I didn't change even though they are pricey. Are there ones I am not seeing underneath the intake manifold?

DVs have been checked and hold pressure. Lubed them up for the hell of it.

Spider hose I'm not sure of its health. That, the pancake, pcv will be the next on my list.

Put brand new MAF and flow straightener to no avail.




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[christianb5s4]

I doubt it's the pancake valve, but PCV valve is definitely a potential culprit. Have you tried disconnecting the MAF and seeing how that affects trims?

[vavJETTAw36]

I doubt it's the pancake valve, but PCV valve is definitely a potential culprit. Have you tried disconnecting the MAF and seeing how that affects trims?

Actually accidentally left it unplugged when I changed to a brand new one. Unplugging it made it worse (in the neg twenties) and after plugging it in it went back down in the teens (~-15).

One thing I noticed about my fuel pressure is that it is actually slightly higher than 51 idle/58 unplugged FPR. Its more like 54/61. Now, this could be the gauge (ecs inline gauge before rail). Does anyone know what the tolerance is?

[vavJETTAw36]

Guys, i took a look at my fuel pressure gauge and it is doing some weird things. What do you guys think? seems to be some excess pressure. Its a 4 bar FPR.

https://vid.me/e/4fkA?stats=1

[vavJETTAw36]

Confirmed my ECS fuel gauge with a different fuel pressure gauge.

~56psi idle, ~63psi no FPR hose

[f4m0u5]

What are you running for a fuel pump? And is hardwired with thicker wire?

[vavJETTAw36]

What are you running for a fuel pump? And is hardwired with thicker wire?

Bosch 044, Stock wiring.

[getslideways]

I wonder if you disconnect the return line (obviously with a way to catch it) if the pressures would change (thinking maybe a kinked return line in the tank from doing the pump install)

[vavJETTAw36]

I wonder if you disconnect the return line (obviously with a way to catch it) if the pressures would change (thinking maybe a kinked return line in the tank from doing the pump install)

I can def give that a try! Anyone else running the 044 with oem pressure (51/58)?

[getslideways]

I thought someone posted up about at what flow rate they started seeing the factory return line get maxed out and build excess pressure, but I am having trouble finding the thread (assuming it even exist and wasnt just a fever dream lol)

[axnjaksn]

interesting......if your return line cannot flow or keep up with the flow, it would cause excessive pressure in the system..definitely a possibility.....is a bosch 044 that much larger than a walbro 450?? I have oem lines and a walbro 450, oem fpr, larger injectors on my stage 3....ive yet to have this happen....just curious if its true, should I be worried??

[okkim]

Confirmed my ECS fuel gauge with a different fuel pressure gauge.

~56psi idle, ~63psi no FPR hose

You should use dampened gauge ;)



(I am testing a fuel pump, it seems that it can't produce enough flow. )

[vavJETTAw36]

You should use dampened gauge ;)



(I am testing a fuel pump, it seems that it can't produce enough flow. )

My Ecs gauge is more stable. I bought that for 20 to confirm pressure. Yea a dampened one would be nice.


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[vavJETTAw36]

Got my fuel pressure in check. It ended up being the FPR (the new one I installed), however, still no change to trims.

[landfill]

The return line is good for well above 500whp.
If it's kinked that's another story. The new FPR
fixed your fuel pressure but your trims are still
fucked up. What are your AFR's? Somethings
causing you to dump fuel. Is your tune a true giac
tune or was it written by emmanuelle design?

[vavJETTAw36]

The return line is good for well above 500whp.
If it's kinked that's another story. The new FPR
fixed your fuel pressure but your trims are still
fucked up. What are your AFR's? Somethings
causing you to dump fuel. Is your tune a true giac
tune or was it written by emmanuelle design?

Emmanuelle Design

Here is a log with my AFR's already calculated (WBAFR column) : https://drive.google.com/open?id=0B2...EgtcExUSzBKalU

[vavJETTAw36]

So I swapped in a tune and hardware from my other S4 and what do you know, fuel trims are normal. So something is off with either the maf housing, tune, or injectors. I'm actually leaning towards injectors due to the fact that I received blue injectors when I should have received red ones. I may have had the wrong ones the whole time.


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[getslideways]

What injector size was the other tune (the one you just put on) designed around & what was the ED one setup to use?

If they were supposed to both be using the same size injector, and one tune works and one doesn't, I'd lean more towards improper scaling on the ED tune.

[vavJETTAw36]

What injector size was the other tune (the one you just put on) designed around & what was the ED one setup to use?

If they were supposed to both be using the same size injector, and one tune works and one doesn't, I'd lean more towards improper scaling on the ED tune.

Tune A: Stage 1 APR using stock injector, stock accordion and stock MAF housing
Tune E: ED 85MM MAF, matching accordion and injectors (Size ??).

So a little info on Tune E. I talked to a member (Devious27t) on here last night that basically owns the master file this tune was built off. We have been comparing hardware. It didnt occur to me to confirm injectors until ive found tune A to work properly. He told me he runs these:https://www.fiveomotorsport.com/013-...high-impedance which is the same injector pictured on ED. The ones I received and installed months ago are blue bosch that are stamped 0280155735. I cannot find info on them other than what is on fiveomotorsports.com, which states they are 198CC https://www.fiveomotorsport.com/1364...55735-55212174

So something is not right here.

[f4m0u5]

Wtf those are some tiny ass injectors!! Wonder if they are just drilled out, wonder ifu can compare pics of the spray holes compared to urs.

Im suprised the car runs with them. It says its adding fuel at idle (that would make sence but you would think alot higher then those trims) but why taking away fuel under part throttle... What happens under wot?

[vavJETTAw36]

Wtf those are some tiny ass injectors!! Wonder if they are just drilled out, wonder ifu can compare pics of the spray holes compared to urs.

Spray holes look like the pics on FiveOIm suprised the car runs with them. It says its adding fuel at idle (that would make sence but you would think alot higher then those trims) but why taking away fuel under part throttle... What happens under wot?

WOT is same, rich but not too bad. Depends on the day!!! ive seen it in 10's but usually 11.5 ish.

Spray holes look like the pics on FiveO's website. .ED has acknowledged there is some issue and is contacting the supplier (fiveOFuelInjectors). He mentioned they were backordered and they were shipping out "alternatives". So, not sure if these are the alternatives or just a mistake, but in any case they are not right.

Its interesting because they gave me a flow sheet showing the flow rate of each injector. I happened to have saved this. The part# on it is the part for the Red Devils, not the Blue Knights. Its kind of shady if you ask me.

[vavJETTAw36]

Wtf those are some tiny ass injectors!! Wonder if they are just drilled out, wonder ifu can compare pics of the spray holes compared to urs.

Im suprised the car runs with them. It says its adding fuel at idle (that would make sence but you would think alot higher then those trims) but why taking away fuel under part throttle... What happens under wot?

Actually I was wrong. Here are the comparisons. Left mine, right blue knights:


Red devils:


Spray pattern is going to be way different!!!

[f4m0u5]

Actually I was wrong. Here are the comparisons. Left mine, right blue knights:


Red devils:


Spray pattern is going to be way different!!!

Yea that looks like a different end or a drilled out end! Get some new injectors !

[vavJETTAw36]

Yea that looks like a different end or a drilled out end! Get some new injectors !

Response from the Vendor to Thomas from ED:

"You have indeed received 013US575 matched injectors.

We have switched to a newer Gen III Bosch injector which is now blue instead of red, but has the same specs.

The quality and flow of the new blue injectors is identical or in some cases, better than the red injector (slightly lower dead times).

Please use the flow specs that were provided with the set for tuning purposes."

Ok, I am not a tuner but I know spray pattern is a huge thing. even if they flow the same, the pattern can atomize the fuel differently. This is why some injectors need to be clocked. Am I wrong about this?

[vavJETTAw36]

Thomas from ED is sending me the red devils from a shop car. Hopefully will fix my issues once and for all.