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91 TBI Issues - Lean?

The graph in the ecm looks like this. And 128 is perfect. Less then that number and the computer is taking fuel away. More than 128 and the computer is adding fuel. And as mark said 105 is maximum the ecm is allowed to take away. I forget what the high number is.

Screen+Shot+2014-02-03+at+9.55.40+AM.png
 
Pulling ECM A and ECM B fuses will clear its memory, correct? I hate pulling the battery cable and reprogramming radio stations and stereo EQ.

I'm planning to bring it into work tomorrow, so I'l see if i can do a log run with and without the o2.

Not going to lie, most of the reason I haven't repeatedly tested with/without o2 is the connector is on the trans above the exhaust, so once its hot, its REALLY hard to plug or unplug the 02 without burning the hell out of my arm. :doah:
 
dhcomp said:
Pulling ECM A and ECM B fuses will clear its memory, correct? I hate pulling the battery cable and reprogramming radio stations and stereo EQ.

I'm planning to bring it into work tomorrow, so I'l see if i can do a log run with and without the o2.

Not going to lie, most of the reason I haven't repeatedly tested with/without o2 is the connector is on the trans above the exhaust, so once its hot, its REALLY hard to plug or unplug the 02 without burning the hell out of my arm. :doah:
Click to expand...
Data logging without the O2 is worthless. O2 gives you the most info.
 
dhcomp said:
Mark,

Definitely didn't get warm during that test drive, was more curious if anything was standing out that would cause overheating in a loaded scenario.

Where in tunerpro can i see error codes? I'll clear the code manually before i log during my friday tow.
In the View Item Lists there's a scroll down to Error Codes.

Did a little research, and see what you are referring to on BLM. What's it actually stand for?
Block Lear Mode or Long Term Fuel Trim.

Before I log 4 hrs of data, is there any "best practices" to get good logs?
That's to long! 1/2 hour tops and save it with a name for what was happening!

Are short/long logs more helpful, does it cut off after a set time, do you want it from cold start? Only want to focus when it starts to warm up?
Warmed up unless your looking for cold start issue.

I'm guessing the "dash" i'm showing in turnerpro doesn't actually effect the data that is being logged, correct? Correct!

Thanks for all your help!
Click to expand...
Answers in Red!
 
Got it. Thanks. I'll run a short log towing this weekend. Will try and do a quick log while driving tmr, but we'll see if I have time.
 
Yes, unplugging the ECM fuses is normally the easiest way to clear it. You don't lose presets etc. From my (way too many times) experience, the time it takes to pull the fuse and insert it is more than enough to clear the codes. You hear 10 seconds, 30 seconds, etc., but I've never had an issue with not waiting at all.
 
dyeager535 said:
Yes, unplugging the ECM fuses is normally the easiest way to clear it. You don't lose presets etc. From my (way too many times) experience, the time it takes to pull the fuse and insert it is more than enough to clear the codes. You hear 10 seconds, 30 seconds, etc., but I've never had an issue with not waiting at all.
Click to expand...

Perfect. Thats what i figured.

Didnt' drive the beast in today, too busy to deal with it.

I'll get some good data on friday.

Thanks Guys!
 
Anyone have a chance to look at this?

Truck seems to be running a bit cooler. No idea why. It was hot yesterday, and it kept cool on the freeway towing, and only got up to 215 or so up the (short) grade.
 
Maybe you found the sweet spot of fuel pressure and once you cleared the ecm it is learning appropriately again?
 
And...running warm cruising on the freeway unloaded today :(

Mark, did you get a chance to take a look at the latest data?

Curious if my o2 sensor is in the wrong spot, causing a forced lean condition.
 
Flowtech Headers
Custom y pipe.

3 wire O2 to fix o2 code after header install
 
Where is the O2 sensor on that stock? If you move the o2 sensor.... there is an adjustment needed in chip. It's measured in milliseconds...
 
eagle mark said:
Where is the O2 sensor on that stock? If you move the o2 sensor.... there is an adjustment needed in chip. It's measured in milliseconds...
Click to expand...

Milliseconds? :doah:

Definitely not close enough then.

Probably easier to just put the o 2 sensor back as close to stock, no?

Who still has a stock y pipe on their truck, and can give me a measurement to something on the frame? How far forward of the front trans crossmember bolt?
 
I'm pretty sure in a stock truck setup the O2 sensor is in the exhaust manifold oulet, like 3" from the #7 cylinder?
 
dyeager535 said:
I'm pretty sure in a stock truck setup the O2 sensor is in the exhaust manifold oulet, like 3" from the #7 cylinder?
Click to expand...

That only applies to the 92+ trucks with the 5.7.

My headers are actually for that application, but i plugged that port.

My 91 (88 style) stock location was in the y pipe.
 
Mine too. It was right where the y came together. Kinda near the shift linkage at the Trans.
 
dhcomp said:
That only applies to the 92+ trucks with the 5.7.

My headers are actually for that application, but i plugged that port.

My 91 (88 style) stock location was in the y pipe.
Click to expand...

Hmm on my 88 02 is on the exhaust manifold ? I guess my motor has been swapped to newer one? I wonder if it cause's problems with the ecu being that close when It's supposed to be in the Y pipe?? :doah: I've been trying to get mine to run as close to perfect in stock configuration before I modded and tuned it.
 
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