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Discussion Starter #1
I have a question regarding readings I am getting on my wideband unit during normal freeway operation. Hopefully some of you more experienced guys can answer them for me. When I am driving down the freeway and encounter a strong headwind or hill I will get an AFR up to 16.0:1 for about 10-15 seconds, then it will jump down to 11.5-12.0:1 for the same amount of time, and then level back off at 14.7:1.

Since the truck is operating in closed loop mode I assume that this has nothing to do with the map that I have programmed it is just adding and cutting fuel to compensate for increased engine load and stoichiometric adjustment, is that correct?

If not what do I need to do to fix the problem?

Thanks,

-Drew
 

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BLOWNYOTA said:
I have a question regarding readings I am getting on my wideband unit during normal freeway operation. Hopefully some of you more experienced guys can answer them for me. When I am driving down the freeway and encounter a strong headwind or hill I will get an AFR up to 16.0:1 for about 10-15 seconds, then it will jump down to 11.5-12.0:1 for the same amount of time, and then level back off at 14.7:1.

Since the truck is operating in closed loop mode I assume that this has nothing to do with the map that I have programmed it is just adding and cutting fuel to compensate for increased engine load and stoichiometric adjustment, is that correct?

If not what do I need to do to fix the problem?

Thanks,

-Drew
How do you know you're in CL? The only way to know for sure is hookin up your ODBII and checking the operating mode but usually thats not fast enough.

Generally, if your truck is running strong it will damn near be 14.7 afr before boosting.
 

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What's your rig and setup?
 

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Discussion Starter #4
2001 V6, 4WD Auto with TRD 3rd gen blower. URD fuel mods. LM-1 with XD-16 display.

I have confirmed that the truck is operating CL while this is happening.

I have noticed in other situations that the truck will run as low as 12.0:1 on long uphills while operating in CL. I thought that as long as the truck was in CL the ECU trimmed fuel to manage a consistant 14.7:1. Am I wrong?
 

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BLOWNYOTA said:
2001 V6, 4WD Auto with TRD 3rd gen blower. URD fuel mods. LM-1 with XD-16 display.

I have confirmed that the truck is operating CL while this is happening.

I have noticed in other situations that the truck will run as low as 12.0:1 on long uphills while operating in CL. I thought that as long as the truck was in CL the ECU trimmed fuel to manage a consistant 14.7:1. Am I wrong?
Not if you have the URD A/F ratio calabrator, that will make a smooth transition into open loop.

That A/F of 16 is very lean, something is wrong there.
 

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It sounds to me like everything is okay. You're probably like I was when I first installed my Innovate LC1 + XD1. You watch it all the time and always think somethings wrong.

When you're in boost, and going up a hill - your AFR should be right at 12.0 for a bit, and then start to level off. If your cruise is set your ECU is adding fuel and acceleration to maintain your speed on the hill, once your speed levels off your AFR's should come back down and stabilize around 14.7. When you're at WOT you want to be stable at about 12.0

When you decelerate fuel is taken from the engine which will cause the AFR to be leaned out at 16.0 - 18.0 for a moment and then it will bounce. It will lean out, then get rich, then stabilize at around 14.7

Like I said - from what you're saying, it sounds to me like everything is probably okay, and acting as it should, and you're just being a little paranoid now that you have that gauge staring you in the face all the time.
 

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Yeah if you're getting the 16 while decelerating that's fine, but if you're getting it while climbing a hill or going into a strong headwind something isn't right there.
 

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mt_goat said:
Yeah if you're getting the 16 while decelerating that's fine, but if you're getting it while climbing a hill or going into a strong headwind something isn't right there.
Agreed - 100%!

Did I read that part wrong?
 

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BLOWNYOTA said:
Thanks for the help. Now I'm going to talk to a doctor about my gauge-paranoia.
Yeah, there is medication for that.:xbeer1:
 

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Discussion Starter #11
I tried to medicate, but I still think something is wrong...

I understand that the truck will lean out if the throttle is chopped. But if the truck is running in CL at 2750 RPM under boost, there is no way that the truck should be seeing 16:1 for more than 1-2 seconds . WTF??? Do I have a bad wideband sensor? what other things can I check? is it possible that my map is causing this?

-Drew
 

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Do you have the URD A/F ratio calabrator too or just the FTC?
 

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What are your fuel trims doing while you're reading that 16?
 

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BLOWNYOTA said:
I tried to medicate, but I still think something is wrong...

I understand that the truck will lean out if the throttle is chopped. But if the truck is running in CL at 2750 RPM under boost, there is no way that the truck should be seeing 16:1 for more than 1-2 seconds . WTF??? Do I have a bad wideband sensor? what other things can I check? is it possible that my map is causing this?

-Drew
The map A is exactly what causes the readings on your wideband. 1-2 seconds if that really it all it is- is nothing to worry about especially in closed loop. If its for longer and open loop then have someone watch the laptop and when you see the wideband go lean haller at him and have him record where the cursor was at (what rpm and psi) and increase the number in that box by .2 and try again until your reading goes back down. If its only closed loop where that happens then your map A is not tuned correctly iin that your fuel trims arent around 0 in those areas. You have no idea how much better it is with the AFR calibrator. It lets you control the fuel in all boosted regions even when youd normally be closed loop, just like your problem area!, ive got my wideband reading 12:1 A/F for all boosted regions, its like and intstant smooth roll on of power, cured all the lag and surging.
 

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VF'N8 said:
The map A is exactly what causes the readings on your wideband. 1-2 seconds if that really it all it is- is nothing to worry about especially in closed loop. If its for longer and open loop then have someone watch the laptop and when you see the wideband go lean haller at him and have him record where the cursor was at (what rpm and psi) and increase the number in that box by .2 and try again until your reading goes back down. If its only closed loop where that happens then your map A is not tuned correctly iin that your fuel trims arent around 0 in those areas. You have no idea how much better it is with the AFR calibrator. It lets you control the fuel in all boosted regions even when youd normally be closed loop, just like your problem area!, ive got my wideband reading 12:1 A/F for all boosted regions, its like and intstant smooth roll on of power, cured all the lag and surging.
how aggresive did you tune your a/f cal? we set mine up prety damn aggresively and im still not seeing 12s untill OL
 

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Gadget said:
Will you email me? I need to ask your permission for something.
Sure, which address?
 

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drabnor said:
how aggresive did you tune your a/f cal? we set mine up prety damn aggresively and im still not seeing 12s untill OL
Im not sure exactly what your asking but by 12:1 Im refering to my air/fuel ratio reading from the wideband a/f ratio gauge. The a/f calibrator gives you full control just like your in open loop, so I tuned for 12:1 in all boosted regions for max performance.
 

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BLOWNYOTA said:
I have a question regarding readings I am getting on my wideband unit during normal freeway operation. Hopefully some of you more experienced guys can answer them for me. When I am driving down the freeway and encounter a strong headwind or hill I will get an AFR up to 16.0:1 for about 10-15 seconds, then it will jump down to 11.5-12.0:1 for the same amount of time, and then level back off at 14.7:1.

Since the truck is operating in closed loop mode I assume that this has nothing to do with the map that I have programmed it is just adding and cutting fuel to compensate for increased engine load and stoichiometric adjustment, is that correct?

If not what do I need to do to fix the problem?

Thanks,

-Drew
When I see odd unexplained variations in AFR I usually suspect a faulty TPS. I have had this happen on one of my own trucks as well as several customers. Full throttle was fine, idle was fine, but the midrange was just whacky. Sometimes it was fine, others it was way to lean and then sometimes it would surge.

I replaced the TPS and everything is perfect now.

Looking over your description of the problem you are having you may consider replacing the TPS. The ECU uses the TPS to know what you are up to and what you are expecting from the engine. If you are advancing the throttle it will enrichen the fuel for acceleration enrichment. If you are reducing the throttle it will lean the mixture, and if you have closed the throttle all the way, it will engage fuel cut. If you have a faulty sensor it can confuse the ECU by jumping radically in voltage range. You could be accelerating, but it is getting a signal that you have closed the throttle and you end up with a very lean mixture, then suddenly it will move to a good spot on the TPS and get a good reading and wham, sudden increase in power, then a bad spot, power loss and lean mix. This is going on all the time and will drive you nuts. If you are trying to tune, you will really be pulling your hair out.
 
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