trying to tune MAF

[mayne]

I think I have Everything Mechanically right:
I put in new o2s
ONLY Tune changes: AFR= 14.4 I removed CAT OVER TEMP cause I've been told it will just get in the way...besides I dont really have a CAT and dont have the rear o2 hooked up)

I drained the 2yr old gas as much as I could and changed the fuel filter.

QUESTION): I only drained from the fuel filter line so I'm sure there is still condensation at the bottom of the tank???? I bought some gas line water remover... should I use it?

1st Scan): I reconnected MAF, first recorded as it idled up to 195F Saved.
The Trims have NOT been learned... they were just reset prior.

2nd Scan): Trying to Learn Fuel Trims!! Started a new (2nd) scan of driving around at temp. I went about 3 miles and was HARD turning at a really slow speed in a parking lot, it died, then would not start again!! So I removed battery and will try to go get the car later.



Mods: whisper lid that isnt closing all the way, K&N, removed EGR
intakes and exhaust manifolds were port/polished a little but NOT the TB or MAF they are stock with the MAF screen in!
I have an exhaust leak at the Cat
I have a super high flow cat and flowmaster muffler

I think that is all that counts (as far as AFR)

[mayne]

dont know why my o2b1 was at 0

[mayne]

I went back and still cant get it to stay running!

It took ALOT of trying to start it before it finally ran at all.
Now, I have to hold the gas pedal down to get it to run but if I let it try to idle on its own, it will die EVERYTIME!
I left it running at 2k-3k rpms for 10 minutes and still the same problem!

Could this be because I removed the gas? air in the line? water in the gas tank?
I dont know what to do except to try tomorrow and flash it back to stock 14.7 instead of 14.4 commanded stoich

BTW, it wont stay running whether the maf is connected or not and even if its up to 195F

[MStefak]

Ill say it before anyone else , you need to post your tune so everyone can take a look and see what is out.

[mayne]

Sorry, I added my tune and mods
I have never messed with the airflow settings

[mayne]

I found out what was wrong!

The brand new o2 sensor's wiring that I had wired myself had wrapped itself around my steering column and broke. I fixed the wiring even though the sensor was bent a little and put everything back together. It still wouldnt start so I checked the Eng Sensor fuse and it was blown. No problems after that! thanks

[mayne]

I got it home and wanted to see how it was doing. I wanted to reset the fuel trims so I can start logging good data. I got LOTS of KR just sitting there idling up to temp!!
I wasnt having KR before? thanks

[mayne]

I have no freaking clue.. I noticed that first thing
14.4 is what I programmed the tune to be as commanded/stoich
When I started it went from 14.4 to 15+ to 14.4 again

[passingpower]

If you look at the counts on those high commAFRs, you'll see they're pretty low and are just transients. you've got bigger issues to fix now. Make SURE your wiring is sound first and no more blown fuses second. Third, is there a block-off plate where that EGR valve was? That's about the largest vacuum leak you can hand one of these engines.

[mayne]

1. Check again for bad fuses.
2. Are you running gasoline or gasohol? (how much in the tank?)
3. Did you install an EGR blocking plate?
--------------------------------------------------------
1. All fuses are good... I think the reason the ltfts werent learning is because I was messing with the command settings (LTFT Learn disabled, CL=disabled, etc)
2. I'm running gasoline... I dont know if there is 10% ethanol in it or not but I would bet there is ethanol in the gas here!!
3. Yes EGR is blocked by a dime I think (no leaks at the missing egr spot)
thanks

[mayne]

I wanted to play with it today to see if it was still having CRAZY KR like yesterday? yes it did

I let the car sit and idle up to temp then I went around the block real quick

[passingpower]

Can you actually HEAR a ping or knock? Or is it more of a rattling sound at idle? Your KR somtimes goes to 0.0 while your off idle so, I'll bet you have a heat shield loose and its generating false KR. Time to get back under the hood.

[mayne]

It wasnt at full temp it was starting at 168F
I been getting KR the last couple runs.
I did another run tonight to see if there was any KR and yes,there was crazy KR.
I dont know why this is happening?

1) is there still water in the gas causing this?
2) is it false KR?
3) is it because trims havent settled in yet?

I dont hear knock, I hear rattling but only at idle
I guess I dont know what knock sounds like.

In my lifetime I've heard a couple spun bearings, I've heard lots of pinging.
I can record some audio if you want.

thanks alot!



EDIT: BTW I have ALL the histograms removed for decel!!!

[murphinator]

you have 15* of kr from just off idle at under 10 tps , something hitting ? exhaust , bad motor mount ,etc...?

[passingpower]

Find and fix the rattle.
The knock WILL go away. It's false KR but will interfere with tuning.
Only then can you start tuning.

[mayne]

I dont have any heatshields or anything so I dont know what it could be?
Could it be because of lifter knock/tap? thanks

[passingpower]

Lifters almost never click to the price of 15+ degrees. Besides, the rattle appeared suddenly. Lifters generaly start as a soft tap and gradually get louder. Should be easy to find being that it's there at idle, you don't have to guess at it while you're driving. Instead, with it running, you can put your head under the hood or under the cradle (while on jackstands) and listen for it. Take a broom handle and press it against parts you think might be making the raket. When it goes away, you've found it! SOMETHING got bent when the O2 wiring harness got wrapped up in the steering. Your best bet is to start looking in that area.

You have to fix the rattle before you can tune. The PCM listens to the block using microphones (knock sensors) and thinks that sound is detonation. It's responding by pulling timing and keeping you in the bad fuel timing table. Before you ask: No, you can't copy your GFspark table to your BFspark table as an easy "fix".