joecar

You would need a 2-bar MAP sensor, so 50 kPa on the VE axis represents 100 kPa (1-bar), and 100 kPa on the VE axis represents 200 kPa (2-bar)... i.e. so your VE table shifts down, but there are other tables affected by this MAP senosr scaling... it would be easier to use a COS from HPTuners or EFILive (whichever one you already have), this does make tuning easier

If you're keeping the MAF sensor, you will run out of MAF at 512 g/s, so you would have to scale MAF/VE/IFR by some factor... in any case, you'll most likely end up tossing the MAF and running VE/IFR unscaled.

irrational

I do have a 2 bar map sensor i adjusted the map sensor 0-5v scaling but im not sure if it scaled the table or not. Im going to try using a custom os and see if i can get it to work.

irrational

Here is a video and my tune.

irrational

As you requested i also took down the pcm and inspected all of the pins, checked all of my connectors for corrosion or bad connections and removed the cover on the pcm to look for water damage. Everything inside looks great, no issues to be found. I thought that the 2002 stock f body OS solved my issue, but come to find out that i had the stock 1 bar map sensor settings instead of the 2 bar settings and that was allowing it to idle somehow by tricking the pcm into reading a different part of the ve table. Using the ve err% table in the vcm scanner and subrtracting/adding those values results in either very rich or very lean conditions, never anywhere near my target. Attempting to lean out the idle using the vcm scanner results in the AFR's going up to around 13 while im commanding 17 AFR and then suddenly go full lean and die if i go above 17 commanded.

ive ordered a new map sensor just in case the one i have is bad and sending a random erratic signal. I also ordered a new IAC valve and a new 0411 PCM since i dont have any friends with a gen 3 pcm i can borrow.

Any suggestions will be followed, im really not sure where to go from here.

kingtal0n

iTrader: (1)

1. you are pointing the camera at the wrong object when you start the engine. Keep it on the laptop, or combined laptop + wideband. how do we know the map input is working. talking is also kind of pointless. Show the computer, start the engine. rev the engine gently, make it slow and obvious what you are doing, no need to say it. We will see kpa ncrease and the little black box will move to a new place and fall back to rest when you stop holding open the TB.

2. that is 10 hours+ of wirng to make it appear OEM. where is all the pretty OEM harness? Can't you get an OEM harness on the motor and use with OEM ecu?

irrational

Fair enough ill cut the chatter to a minimum. Ive found that the STIT were still engaged and adjusting fueling at idle even though i had them disabled in the closed loop section, zeroing out all closed loop tables sort of solved the "starts but then goes full lean" issue. Now that is gone immediately after i start the engine but now its only when either i command a higher AFR through the scanner, set the ve table above 13:1 or the computer attempts to command stoich through closed loop, they all result in the same thing dead lean and the engine stalls. The engine runs great at 12.5 and lower but any higher and it starts surging from 16-20+ afr or die.

Ill take another video and show the laptop this time. The reason i video'd the wideband was to show what the actual wideband and not what the computer was saying, since the guy above seemed to not trust the computer input.

Alot of the harness you see is the cars electrical harness i made since the car came without one, ive left it bare to troubleshoot problems so i dont have to constantly remove the shielding. I modified a stock 5.3 harness to a standalone to work in this car its hard to see probably in the video. im considering buying a stand alone harness that way i know the harness is good.

irrational

This is a terrible video, i forgot to change my video quality on my phone before i took it but it shows exactly what im going through no matter which way i go at reducing the fueling it results the same. i also included the same log that i was recording the in video.

Its too late to be revving the engine in my driveway ill do that tomarrow.

irrational

SOLVED SOLVED SOLVED SOLVED

Replaced the PCM tonight licensed it and copied my map file over to the new pcm. Turned the key and it fired right up without any issues. MAF failed about 5 seconds into running it purred like a kitten.

Literally 10 minutes after firing it up on the new pcm i was out taking it for a test drive enjoying life. What i think was happening was the pcm was not failing the maf for some reason. I had everything i could think of turned off in the tune to fail the maf hz fail frequency, actual maf hertz and so on. the p0101 p0102 p0103 were all showing failed in the DTC page.

Either that or closed loop STIT would not turn off for some bizarre reason and were still affecting idle fueling even though it showed zero on the channel. Thankyou for your guys time, i cannot say how happy i am to finally have this problem out of the way. And in case anybody else has this issue here are the symptoms/effects that i was having:

Even on stock map engine run super rich below 11.0 afr, adjusting ve table causes lean condition.
Starts and runs until afterstart enrichment decays and then runs dead lean and stalls, afterstart transition through throttle actuation causes instant dead lean stall when return to idle.
Engine runs very rich/lean in the 400-2000 range depending on how rich/lean idle is at that time.
Engine will not restart until alot of fuel is added to the ve table
Engine runs super rich after adding fuel to ve table, and reducing fueling from the ve table slowly will allow you to lean the AFR's to about 13:1 and then go full lean and start over again.
Attempting to adjust AFR in VCM scanner will cause engine to go full lean and die at around 13:1 AFR
Letting the computer attempt to adjust AFR through STIT or LTIT will cause engine to go full lean and die around 13:1 AFR
Idle could only be accomplished after setting base idle airflow to 200 across the board and slightly leaning out ve table, this would cause my afr gauge to peg full lean but would idle somewhat while missing like hell.

Possible things to check before replacing ecm:
If your having the same issues as i was, try raising transient fuel mg in .020 increments and see if you can get the idle to stabilize and reduce transient mg slightly from there to atleast trouble shoot it.(assuming your base ve table is good and workable) At around .0120 i could get a decent 12.5-13:1 idle with my ve table at 40 in the 15-50 kpa range, below the actual cutoff of the transient.

Try changing OS's from a custom os to a stock 2001 or 2002 f-body os.

I was also having an issue with closed loop STIT being enabled and adjusting fueling at idle even when it was turned off, zeroing out entire closed loop page stopped that from happening.

Again big thanks to montecarlodrag,joecar,jakefusion,darth and kingtalon for the advice.

statesman

I thought it was the PCM.

Good to see that you got the problem fixed.

joecar

Glad you got it solved, thanks for posting back.