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Wideband reading lean at wot

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nicknorth11

15+ Year Contributor
663
7
Feb 9, 2005
Grand Blanc, Michigan
I had a good 93 octane tune, and when that tank ran out, I switched to E85. I changed my global settings with link and went to the highway to tune a bit. After several pulls, I noticed that no matter how much fuel I added, I wasn't able to get my afr's below 13:1 or so. On top of the global change, I've added an additional 30% of fuel! Wideband still reads lean at wot. I know for a fact it's running pig rich at this point, but I have no idea why my wideband continues to read lean. Btw, it shows around 14.7 at idle, which seems to me an indicator that there is no exhaust leak.

Boost leak test held at 30psi. I didn't test any higher.
I've checked for exhaust leaks and can't see/hear any.
I've swapped out sensors. (The alternate sensor was an old one I had laying around, not new, but was working back in the day.)
 
I'm running a walbro 450 and only pushing 25 lbs of boost, so I know the pump is fine. I know it's rich because all I should have to do to change from 93 to E85 is change my global fuel settings (and maybe decrease boost/timing to account for lower octane, of course). However, changing the global left the wideband at about 13:1, plus or minus. After adding ANOTHER 30% fuel, guess where my wideband was reading. You guessed it, around 13:1, plus or minus. You can't add that much fuel and not change your afr's, but that's what my wideband is telling me is happening.
 
Man I just started a thread with a very similar issue. I'm trying to figure out if my issue is from poor calibration with ECMlink and my Wideband or maybe I'm running out of pump. Or maybe I have an exhaust leak (I haven't been able to find one).

At 18-20PSI boost my AFR might start at 12 and then creep up to 14 through the gear at WOT. My AFR estimate in ECMlink isn't matching the reading with my Wideband... Its way off. For example: my open loop max octane table will be set at 9.5 and the wideband shows my AFR is 12 and creeping to 14. I was thinking ECMlink is leaning out my mixture because it thinks the car is a lot richer than it is. Or maybe my Autometer wideband is wrong.

I tried adding more Global fuel but then the car runs super rich when I'm not at WOT. It even smelled rich. I also tried adding more fuel when above 4500 RPMS but it only slightly improved things and my ECMlink still doesn't match my wideband. :confused:

I would think a walboro 450 could handle 20PSI on my GT35r but I don't know that. Maybe its time to go with the pump I should have bought in the first place. Magnafuel MP-4303...
 
There is only 1 reason I started questioning my pump.... When I'm at say 80% throttle my mixture stays rich and doesn't tapper lean. It only does this at WOT and full boost.

I'm still 90% sure its some type of tuning or calibration issue. My data log says I'm holding 9.5 AFR when wideband shows 12-14. I tried dropping my AFR max octane tables by -1. but it didn't seem to do anything. It just made the car run rich at partial throttle.

Have you checked your data log in ECMlink Vs your octane tables under the live access tab? I just logged a WOT pull and then clicked on the octane table... Clicked track datalog and could see its saying 9.5AFR in the table and on the log. When my wideband is showing 12 - 14. Not sure I'm doing this right but trying to eliminate errors in tuning before I go on to upgrading my pump or searching mechanical issues.

I've read a lot about guys running a boost-a pump with a Walboro 450. My plan is to go with the inline Magnafuel MP-4303 over the boosta pump. Our pumps could be the problem.

What turbo are you running?
 
I'm running a 50 trim, good for only 46 lbs/min. I'm going to go drive either tonight or tomorrow and run my tank to empty and then put 93 back in it. While I'm out, I'll turn my boost down very low and see how it responds. Ecmlink is saying I'm around 9:1. It used to say 8:1, but I took out some of the fuel I had previously added.
 
I have it wired into the ECU and am looking at the estimate on link.

I just got in from doing a bunch of pulls and what I found is that my wideband readings aren't responding to fuel adjustments like they should. I started by turning the boost down and zeroing my fuel sliders. I then added fuel. Then increased boost and did the same thing. My results follow:


Low boost; Fuel at 0%; AFR around 13
Low boost; Fuel at 12%; AFR around 12
Low boost; Fuel at 23%; AFR around 12

High boost; Fuel at 0%; AFR around 13
High boost: Fuel at 0%; AFR around 14
High boost; Fuel at 23%; AFR around 13

I tried driving my tank dry, but there's a ton in there, so that's a no go. Everything I see about the Walbro 450 says it can push way more fuel than we're demanding, so I'm having a hard time believing this is fuel pump related.
 
If your output is wired to the ecu, and youve got the output programmed so that Link is reading AFR the same as the gauge, you shouldnt be looking at afr estimate. I do agree that theres got to be something off that is preventing you from being able to richen up the target afr. You two are having the same trouble Im having, exept Im still on 93 pump, and my problem began suddenly. Here is a link to my own thread, just so you can see everything Ive tried, maybe itll save you the trouble checking these things. Start from the top and youll see all the junk Ive replaced, checked and tested before I checked the CTS and TPS today.
http://www.dsmtuners.com/threads/lc1-reading-lean-under-wot.485749/#post-153469795
 
I don't have my wideband wired to the ECU. It will be a day or two before I have time but I will wire to the ECU and program link to read the same as my gauge. I bet that is my issue. At least I hope it is. Thank you for your help. I'll keep you guys posted
 
I have it wired into the ECU and am looking at the estimate on link.

I just got in from doing a bunch of pulls and what I found is that my wideband readings aren't responding to fuel adjustments like they should. I started by turning the boost down and zeroing my fuel sliders. I then added fuel. Then increased boost and did the same thing. My results follow:


Low boost; Fuel at 0%; AFR around 13
Low boost; Fuel at 12%; AFR around 12
Low boost; Fuel at 23%; AFR around 12

High boost; Fuel at 0%; AFR around 13
High boost: Fuel at 0%; AFR around 14
High boost; Fuel at 23%; AFR around 13

I tried driving my tank dry, but there's a ton in there, so that's a no go. Everything I see about the Walbro 450 says it can push way more fuel than we're demanding, so I'm having a hard time believing this is fuel pump related.

Just to clarify, are those AFRs wideband readings directly/through link, or AFR estimates in link?
 
So, I dont know if you guys have made any progress, but I may have found something tonight. My IAT is a static 32* F, so Im not sure how greatly it effects open loop fueling, but Im going to try and figure it out. Funny thing is, I tried another maf when this first came up, and there was no change in the lean condition, so Im now going to try another maf again and this time pay attention to whether or not Im getting a good IAT reading and if not, Im going to have to check the wiring from maf to ECU cause these rarely go bad and you usually get a CEL for a bad temp sensor...

Edit: It was my fault the IAT was reading the way it was; I did not have the software (Tunerpro RT) configured to utilize the lookup table properly. Got the error handles and now its fine. Could have been a TPS openloop enrichment problem, I will be finding out tonight, and if not, Im going to have to get a new wideband controller cause Im all out of ideas.
 
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Thanks for the update. I was wondering if you guys made any progress. I haven't had a lot of time to work on the car this week. Last night I was going through all of my fuel settings in ECMlink. I found a couple of problems. Since I'm using AFR estimate, I didn't have my stoich ratio adjusted for E85. I think I have some type of a noob tuning issue since I am still learning ECMlink. At least I hope so.

The only strange thing is that no matter how much fuel I add I still go lean under full boost above 4500-5000 RPMS.
 
Are you using the fuel sliders, or the direct access maps to adjust afr at wot and boost? You should just be using the direct access maps with the fuel sliders zeroed out. Also, I do believe 30% - 40% global fuel should offset E85 quite well, since stoic for pump gasoline is 14.7:1, and stoic for E85 is 9:1. So, set injectors between 30- 40% less than what you would normally set them to if you were running pump gasoline and you should be close.
 
I have FIC 2150cc injectors. I used the calculator in link and factored for E85. I came out with a Global fuel of -63.3. I've been running zero dead time.

I tried adding more fuel with the direct access tab but it didn't seem to do anything. So I tried adding fuel with the sliders at higher RPMs. My car still ends up going lean (WOT pull starts at 11-11.5 and then ends up at 14).

The one consistency that I noticed is the AFR Estimate in link isn't matching my wideband. Thats when I spent some time reading last night and discovered that I should have set the stoich ratio (Under AFREst preferences). Not sure that will help. My thought was maybe ECMlink thinks the car is richer than it is and causing it to not to add enough fuel. I also figured out that my boost estimate wasn't factoring for altitude. I'm in Colorado at around 6500 feet above sea level.

About to go play with the car to see if I can make progress.[DOUBLEPOST=1413501806][/DOUBLEPOST]Thats also why it might be good for me to set up my wideband to log in ECMlink.
 
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Are you using the fuel sliders, or the direct access maps to adjust afr at wot and boost? You should just be using the direct access maps with the fuel sliders zeroed out. Also, I do believe 30% - 40% global fuel should offset E85 quite well, since stoic for pump gasoline is 14.7:1, and stoic for E85 is 9:1. So, set injectors between 30- 40% less than what you would normally set them to if you were running pump gasoline and you should be close.
There's no way it "should" be done. The ECU reacts to the sliders just fine. Not saying DA tables aren't "better," but in this situation, sliders work. I am also using the sliders, as I have been for the last ten years. I've run e85 in the past with the sliders as well, and that has also worked perfectly.

I have FIC 2150cc injectors. I used the calculator in link and factored for E85. I came out with a Global fuel of -63.3. I've been running zero dead time.

I tried adding more fuel with the direct access tab but it didn't seem to do anything. So I tried adding fuel with the sliders at higher RPMs. My car still ends up going lean (WOT pull starts at 11-11.5 and then ends up at 14).

The one consistency that I noticed is the AFR Estimate in link isn't matching my wideband. Thats when I spent some time reading last night and discovered that I should have set the stoich ratio (Under AFREst preferences). Not sure that will help. My thought was maybe ECMlink thinks the car is richer than it is and causing it to not to add enough fuel. I also figured out that my boost estimate wasn't factoring for altitude. I'm in Colorado at around 6500 feet above sea level.

About to go play with the car to see if I can make progress.[DOUBLEPOST=1413501806][/DOUBLEPOST]Thats also why it might be good for me to set up my wideband to log in ECMlink.
I don't think this is your problem, but I highly doubt a deadtime of 0 is correct for you. You should look into that and set it appropriately. My car is doing the exact same thing. If I add fuel, it will help in lower RPMs, but it always ends up going lean at higher RPMs. AFRestimate, to my knowledge, is just an FYI for the user. The ECU doesn't take this value into account. Also, in WOT, the car is in open loop, so the ECU doesn't care what readings it's getting. Open loop is completely controlled by the user.


I've tested my fuel pressure and MAF sensor in the past couple of days. Fuel pressure is rising at 1:1 with boost, and MAF signal is reading appropriately. I'm going to try to borrow a wideband in the next few days to see if that helps.
 
Forgot to mention that I added my deadtime under injbattery adjust.

Here are my settings:
7 2485
9 1566
12 817
14 628
16 463
19 396

I also added about 65 usecs of deadtime under the fuel tab which seemed to smooth out the car.

Then I added 30% more fuel with the sliders from 4500RPMs - 10000RPMs. That seemed to help my AFR but I still pop above 13.2 at WOT. The car felt way faster after adding 30% fuel though. Yeah if I drop my global fuel below 63.3 then the car just runs too rich at low RPMS.

I have to be running out of fuel pump. I mean 30% extra fuel and still going lean. I want to turn up my boost a bit in the future too. I haven't tried turning my boost way down to see if that helps. Might do that tomorrow.

Let me know if changing your wideband helps. Thats my thought. Either 1) My wideband is inaccurate 2) I'm running out of fuel pump 3) I have a leak or issue somewhere in my fuel system or a bad sensor somewhere. My in cab fuel pressure gauge is broken. I just have the one on my regulator under the hood.

What MAF are you guys running? I've got the stock 2G. I wonder if putting on a GM MAF would help this. I know this problem started suddenly for you guys. my car has never been 100% dialed in.[DOUBLEPOST=1413606046][/DOUBLEPOST]One other thing. Have either of you guys re-wired your fuel pump? Mine has the stock wiring. I was reading that the stock wiring can cause low voltage at the pump. I'm wondering if this is my problem.

I'm not sure this is a good kit but going with something like this http://www.ebay.com/itm/DSM-FUEL-PU...r_Truck_Parts_Accessories&hash=item3cb685b0d4
 
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I've read a lot about guys running a boost-a pump with a Walboro 450. My plan is to go with the inline Magnafuel MP-4303 over the boosta pump. Our pumps could be the problem.
For what it's worth, I run a single in-tank 450 + a BAP at 45psi boost. This is with e85 and on stock fuel lines (aside of the banjo bolt on the fuel filter, which I regret doing).

StrokerMax said:
One other thing. Have either of you guys re-wired your fuel pump? Mine has the stock wiring. I was reading that the stock wiring can cause low voltage at the pump. I'm wondering if this is my problem.
Voltage is everything.
 
Yeah. I'm going to rewire my pump next week. I'm sure that will help. If I still have problems then I am going to look at a BAP or Magnafuel inline pump. Then I won't have to worry about turning up the boost. My car is built for it and I'm running so conservative around 18psi. Just need more fuel delivery I guess. All my lines are aftermarket. I ordered a new Aeromotive fuel filter too.
 
18psi is 14b territory, you can do that with a 190 pump. I doubt your issue is your fuel pump, although you should rewire regardless.

StrokerMax said:
The one consistency that I noticed is the AFR Estimate in link isn't matching my wideband.
This is 90% of the game.

StrokerMax said:
Thats also why it might be good for me to set up my wideband to log in ECMlink.
This is damn near required to get the car calibrated in all aspects.


Post a log when you get your wideband setup.
 
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