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View Full Version : Has anyone ever had a ROM tune get lost,corrupted or wiped?



janders211
03-25-2007, 09:18 PM
My car has been running lean up top..to the point where I need 70psi base FP with no AFC corrections to get to a proper AF. The ROM tune I had used to be a great 12:1 AF.....and I've tried/diagnosed and replaced just about everything air or fuel related (i.e. no leaks, FP or other problems) over the last year including:
FPR
MAF
TPS
CAS
coolant temps sens
fuel pump
injectors
plugs
fuel filter
coils
craploads of leak tests

I talked to a guy from nismo, at length, and a few others who all seem to say it seems that the ROM tune is 'bad'...i.e. somehow the chip was corrupted (the unseen eeffects of UV radiation..I'm calling AL Gore!).

Has anyone else EVER seen this?

klattr1
03-25-2007, 11:01 PM
does fuel pressure drop throughout your powerband?

TS4l
03-25-2007, 11:16 PM
As Klattr1 said have you checked the fuel pressure to make sure its rising like it should or replaced the fpr? I have a hard time beleiving the chip would just crap out unless you did something like hook the battery up backwards or shorted some major electrical system.

janders211
03-26-2007, 09:17 AM
As Klattr1 said have you checked the fuel pressure to make sure its rising like it should or replaced the fpr? I have a hard time beleiving the chip would just crap out unless you did something like hook the battery up backwards or shorted some major electrical system.
I have a hard time believing it too-but I'm running out of other ideas

I have a permanent fuel gauge hooked up-and I even tried a couple of different FPR's. My FP raises with boost like it should

klattr1
03-26-2007, 01:48 PM
what size injectors do you have? what mafs do u have? what size turbo and how much boost are you running?

whats the max duty cycle you are seeing and what about the max mafs voltage you hit?

wizdom240
03-26-2007, 05:39 PM
What rom tune are you running? I had a rom tune that I bought from japan that went corrupt; well actually two of them, blitz and avance. They ran great for a few months then gradually the motor had idle and driveability problems. I put the stock ecu back in, then everything was perfect again. A friend of mine who has an eprom writer showed me those rom tune had corrupted maps.

janders211
03-26-2007, 06:21 PM
GT28R(s15) ~14psi
Deatschwerks 555's (all cyllinders run equally lean/rich-so not a likely problem-plus I've tried 2 brand new sets)
z32 MAFS (I'm on my 3rd)
Enthalpy tune for all of the above(which used to be a apot on 12:1 AF)

MAFs and injector duty cycle 'used' to be good- but my datascan/conzult plug or my computer connection stopped working so I can no longer diagnose via them.

anyone want to rent me an enthalpy ECU with the same setup .lol

Epstein
03-26-2007, 06:28 PM
I'll rent you an Enthalpy ECU. Just cover shipping. Shoot me an email at the Enthalpy gmail address.
So did your Consult interface die or did the ECU stop responding? When the ECU stops responding, that means the tune is corrupt for whatever reason. Usually with the version 1 board which is socketed, the board just came loose. Check that first.

janders211
03-27-2007, 11:38 AM
PM'd

Kingtal0n
03-27-2007, 11:53 AM
The only things that will generally hurt a ROM is:

#1: EMI Electro magnetic interference... I.e. Sometimes people leave MSD boxs near their ECU which can cause it to slowly degrade. Devices such as Ignition coils, plug wires, Radios, igniters, all emit bands of EMI that can degrade or "re-arrange" the 1's and 0's (bits or +'s and -'s boolean data) stored inside the ROM.

#2: Magnets. Anything with a magnet will completelly "format" a memory block. Memory consists of 1's and 0's, a magnet basically rearranges a block so that it all reads 1. or 0. Depends on how you hold the magnet.

#3: Voltage. The ECU itself, or the way its wired, can degrade the ROM, especially if the rom is loose, or the contacts become dirty. Anytime you have an electrical connection via metal you have corrosion. try pulling out and replacing the ROM chip itself to see if this is the cause. Also voltage spikes through the car's electrical system (mainly during cranking) can damage an ECU if it is not properlly grounded. Check your grounds.

#4: UV radiation can erase SOME EEPROMS. Sunlight contains UV.

#5: Too many re-writes. An erasable or re-programmable ROM or FLASH chip thats been written too many times becomes like a re-copied piece of paper, it degrades in its ability to hold information without corruption. if someone had re-tuned your chip too much, this could be the root of the problem. The same happens if you keep copying CD's one after another, one from the last. Eventually the CD-R will have a harder and harder time reading the last recorded CD, until eventually it wont recognize it or give you under-run errors. CD's also store 1's and 0's like a memory block, or hard drive, although the data is physically inscribed to the disc via laser.

I can think of more, but im having lunch.

pampadori
03-27-2007, 12:02 PM
i think this post was written very well without the usually, hatefullness towards the company making the part. good job to Enthalpy on their honesty and helpfullness too.
you bunch of grownups! :0)

i don't know how many threads i've read that are just full of slander and he said she said crap. parts break, cars hit horrible potholes, the moon aligns a certain way and sometimes you have to deal with a problem. this is how it should be handled.

Epstein
03-27-2007, 12:17 PM
KingTalon's summary is pretty good. #1 shouldn't apply under normal conditions because the case is grounded. It should do a pretty good job of keeping out EMI. #2 I'm not 100% certain on, but I don't think EPROMs are susceptible to magnets. #3 could happen on a voltage reversal, but that would probably toast the ECU. The EPROMs are so far back in the circuitry that any voltage anomaly that would affect it would likely wipe out the rest of the ECU. #4 we don't use windowed EPROMs. Only SST's finest 27-series. #5 if customers have been rewriting our chips, I sure don't know about it, haha. Most of our chips are only written once.

#6 is ESD. You forgot that one KingTalon :) . I have corrupted one EPROM through ESD. Good thing we test everything that we send out.

Kingtal0n
03-27-2007, 01:08 PM
KingTalon's summary is pretty good. #1 shouldn't apply under normal conditions because the case is grounded. It should do a pretty good job of keeping out EMI. #2 I'm not 100% certain on, but I don't think EPROMs are susceptible to magnets. #3 could happen on a voltage reversal, but that would probably toast the ECU. The EPROMs are so far back in the circuitry that any voltage anomaly that would affect it would likely wipe out the rest of the ECU. #4 we don't use windowed EPROMs. Only SST's finest 27-series. #5 if customers have been rewriting our chips, I sure don't know about it, haha. Most of our chips are only written once.

#6 is ESD. You forgot that one KingTalon :) . I have corrupted one EPROM through ESD. Good thing we test everything that we send out.
I didnt know he was using an Enthalpy rom tune, I thought it was a JWT or something.
And although I wasnt sure if the ROM would be affected by magnets or not, I was pretty sure anything that got that close to the ROM chip on the ECU would wipe something clean- probably a neighboring ROM, so even if your chip isnt susceptible something else most likelly is nearby. When I think ROM I think RAM and most of this info is from my electronics course at school for my MCSE and A+ back in the day :D

There really is no telling with electronics, especially ECUS. there arnt any good direct diagnosis proceedures for them, besides does the car start or not, If something is corrupt, loose, bad, slightly burnt, you cant really tell unless you pull apart the board and stare at each individual component and even then you would need to know the specifications for each one and go through them with a multi meter and spend several hours trying to locate the bad capacitor or soldier spot thats causing the issue.

What Im trying to say is its a lot faster just to swap it out real quick and test a different ECU rather than troubleshoot a possible corrupt board/ROM chip. Which you knew already, so Ill stop here. Yes Im done with lunch.

And Chris @ Enthalpy is the man. He will not let you down, I promise that.

janders211
04-02-2007, 12:01 PM
THanks to Chris @ Enthalpy - I tested a known good ECU with basically the same tune.
My car still needs 50(57)base fuel pressure and +10% up to 5600 to run without detonating....i.e. a problem with the ECU is eliminated.

ECU good- :)

Now as for what's causing the lean-ness I'll have to dig deeper

However, by the process of elimination I'm pretty sure a flushbot, or changeatron is to blame..somehow using their shapeshifting powers to disrupy my AF.

It's more than likely the MAF circuit (i.e the wiring between the MAF and the ECU)- or just some crazy leak that's remaining well hidden between the MAF and turbo.

klattr1
04-02-2007, 12:47 PM
did your consult port stop working around the same time you started noticing the afrs going lean all the sudden?

once you get the consult port working, that will help you out for sure in diagnosing the problem.

im interested in what you'll find out.

janders211
04-02-2007, 06:21 PM
no- the consult port connection to my computer has always been sketchy- at best worked 1 out of 3 times I'd boot the computer

1. the laptop is old as dirt (needed it old to have the RS232 serial port)
2. the Datascan cable supplied is fragile-and amateur-ish
3. my ECU harness didn't have the metal pins that connected to the consult wires- so I had to hardwire in a consult port to the ECU.