Worst... Tune... Ever...
04-30-2008, 09:08 AM
#1
Worst... Tune... Ever... A friend of mine recently blew his 130K cammed motor. He had a regional shop (Not on LI) replace the motor with a fresh LS2 short block, a custom cam, and some trick flow heads. Pulled about 420/405 on their dynojet.
The very next day, he comes to me complaining that the car bucks like hell, drives like complete ****, and sputters and pops above 3K rpm. He swings by the house on saturday and we hook up the logger and take it for a spin. The car saw a steady 4* of timing anywhere over 25% throttle. There we backfires, violent popping, and it totally broke up during any acceleration over 3K, no matter how mild. So now we try and download the tune. Winds up they didnt even put the correct OS on his ECU, so I could not edit it for him. I had to rewrite the whole O/S using my stock file just to get to the point it was tunable again. Anyway, I could still read the tune this shop gave him and reference some of the tables. Needless to say we found out why the car ran like crap...
I dont know who tuned this MAF table, or how they thought they were improving it, but the last time I saw anything this jagged, it was cutting down trees in the yard.
Now take a look at this spark table. Im sure that makes for a smooth transition when you hit 3200 rpm.
Anyway, fixing these two tables, as well as a few tweaks here and there some other places and that car runs well again. Just though you guys might be interested in the kind of stuff that passes for a pro tune from some shops that obviously just don't give a crap about the customer. In fact, this tune is so bad, its not even like they took the easy way out and did a bunch of short cuts. If I didn't know any better, Id say they were trying to sabotage the motor!
The very next day, he comes to me complaining that the car bucks like hell, drives like complete ****, and sputters and pops above 3K rpm. He swings by the house on saturday and we hook up the logger and take it for a spin. The car saw a steady 4* of timing anywhere over 25% throttle. There we backfires, violent popping, and it totally broke up during any acceleration over 3K, no matter how mild. So now we try and download the tune. Winds up they didnt even put the correct OS on his ECU, so I could not edit it for him. I had to rewrite the whole O/S using my stock file just to get to the point it was tunable again. Anyway, I could still read the tune this shop gave him and reference some of the tables. Needless to say we found out why the car ran like crap...
I dont know who tuned this MAF table, or how they thought they were improving it, but the last time I saw anything this jagged, it was cutting down trees in the yard.
Now take a look at this spark table. Im sure that makes for a smooth transition when you hit 3200 rpm.
Anyway, fixing these two tables, as well as a few tweaks here and there some other places and that car runs well again. Just though you guys might be interested in the kind of stuff that passes for a pro tune from some shops that obviously just don't give a crap about the customer. In fact, this tune is so bad, its not even like they took the easy way out and did a bunch of short cuts. If I didn't know any better, Id say they were trying to sabotage the motor!
Last edited by GuitsBoy; 04-30-2008 at 09:20 AM.
04-30-2008, 09:33 AM
#4
Since it was not my car, Its not my place to identify the shop. Hopefully they'll make things right and give him a refund or something. We totally rewrote his tune starting with my own bin, so its not like were using the shops tune anymore. And who could blame us?!?
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04-30-2008, 12:40 PM
#8
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If you're going to take someone's money and tune their car, be prepared to stand behind your work. I don't care what details there are. Lots of tuners put canned files into cars without doing any tweaking, and it appears it may have happened here.
Thank you
04-30-2008, 12:45 PM
#9
Being a tuner myself--I find we are always 1st to blame whenever something goes wrong--I have gotten phone calls at midnite before from an irate customer who says he is getting codes--When I have him give me the code # -I find out it was from a loose gas cap !! EVAP small leak code --Anyway point I'm trying to make---I agree the tables are way whacky but I can't see how any tuner even with minimal experience would purposely tune it that way--Computers are crazy sometimes i see them go bezerk in stock form--Without knowing ALL the details , the history of the car itself and everyone who had their hands on the ECM I would not critize any tuner--Why would the O/S numbers not match ? The tuner probably was just tuning the car --He would have no reason to change ECM's which is why they don't match--Someone has changed the computer--Too many details are left out to make judgements on anyone
But really, look at those graphs! Seriously, how can somebody put out work like that?!?
Last edited by GuitsBoy; 04-30-2008 at 01:00 PM.
04-30-2008, 12:50 PM
#10
But I agree that they need to stand behind their work.
04-30-2008, 01:18 PM
#11
What god awful can did a MAF table like that come out of? Look how jacked up those cells are. How can a maf steadily increase in Hz, but jump up 50 g/sec, then drop 40, then back up 60, down 55, etc. etc. It defies logic to think that increased MAF frequency could EVER indicate a drop in airflow.
But I agree that they need to stand behind their work.
But I agree that they need to stand behind their work.
04-30-2008, 01:19 PM
#13
no, the ecm was probably not changed, some tuning software (such as efi live) allows you to write any OS into any PCM, with any vin, and just the more strict tuning software such as hptuners, requires the OS to match the vin, (so you cannot get around thier licensing scheme)
The ECM doesn't care if you write all FF's or OO's to the memory, it will take it (it just may be dead afterwards
)
Ryan
The ECM doesn't care if you write all FF's or OO's to the memory, it will take it (it just may be dead afterwards
)Ryan
04-30-2008, 01:22 PM
#15
no, the ecm was probably not changed, some tuning software (such as efi live) allows you to write any OS into any PCM, with any vin, and just the more strict tuning software such as hptuners, requires the OS to match the vin, (so you cannot get around thier licensing scheme)
The ECM doesn't care if you write all FF's or OO's to the memory, it will take it (it just may be dead afterwards)
Ryan
The ECM doesn't care if you write all FF's or OO's to the memory, it will take it (it just may be dead afterwards
)Ryan
04-30-2008, 01:41 PM
#16
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Even if they didn't look back at the final tune, or test drive the car on the street shouldn't a flag have been raised when they saw an LS2 with a "custom cam" and trick flow heads only make 420 hp? *I know the owner of the car and these were dynojet numbers.
04-30-2008, 02:27 PM
#20
What I can't quite figure out is why YOU were able to tune the car before without any trouble and now the OS # and VIN aren't compatible---Somewhere, somehow the ECM seems to have been changed---The ECM won't let you download a tune if it does not have the proper OS system--Doesn't make sense that the 1st tuner made tuning changes and now your 2nd tuner gets a message saying the OS # is not proper and has to overwrite a complely new program
When his motor blew up, he went to the shop to get all the work done. They must have uploaded a different O/S to the ECU.
To get past the lock, I had to do a full write - rewriting the O/S as well as the bin. I used my car's bin file since we both have 2002 cars. I still dont know what OS the tuner had uploaded. Not sure how to find out what the OS number is.