Chips Ahoy Matie!

 

If you are real nice, say please and thank you and PM me your email, I will send you a STOCK LT4 file that came from a Jet tuner if you need it. You can import it and your supposed stock one into the Jet software and do a comparison. Then you will know if anything is changed.

Now as far as the Jet box crashing and ruining your PCM/ECM/ECU. What are you running it on and what OS ? I am running mine on a dedicated Windows XP laptop. It was developed on XP and performs best on XP. It has to be run in XP compatibility mode on later OS's. Which isn't the best. Folks do get away with it doing it like that.

 

Hi Doc,

Please, pretty please with a cherry C4, send me the stock LT4 calibration files Thank you.

I was using my 10 year old HP laptop running Vista and had zero issues with the Jet Flash program receiving the calibration data from the PCM. The program only crashed the one time I attempted to upload what was supposed to be a base calibration file that I created using a copy of my saved file and then imported the base file data into it. I carefully looked through a saved text printout of what I tried to upload vs what was in the source of the base file and all looked perfect. Multiple attempts to salvage the corruption got me nowhere and Flash never crashed during the attempted recovery processes.

I do have one laptop with XP SP2 on it. I better see if it can still wake up. It has the barest minimum software loaded as I recall. I forgot all about it. I’ll give it a shot. Thanks for the reminder.

This C4 is my only transportation at this time so getting it up and running again is high priority. Have a little girl’s birthday party to attend tomorrow evening and I don’t want to have to call for a Lyft ride to get there, lol

Thanks everyone!

 

If you bring it back to life, make sure the battery will hold a charge long enough and strong enough for the burn or a good clean power source to plug the charger into.

Other than LT1 vs LT4 and some painted on stripes your car is very similar to mine

 

I posted the bins in post #5.

You can change the VIN with JET... just dig, you will find it.. it is hard to find... dig dig dig If I had mine running Id tell you. But it is in a non-expected location.

 

I have an lt4. In fact, I have Grand Sport calibration thanks to Dr Cook Pretty cool cuz it has automatic schedule in it even though they never made one.

I was running it on a virgin copy of XP on a desktop, not laptop. Make sure all of your accessories are off.. like AUTOMATIC HVAC... and then put a battery charger on that is of a high amperage capable. I had mine set to I think 2 amps but it was capable of 15.. so you are covered. Also fully charge your battery. And if you dont know if your battery is good replace it. The software has no error control at all. It was never finished. But we are lucky to have it for our red headed step child obdii cars.

I think I had an auto fan control kick on or something.. I dont know for sure. There is another theory that those chips can only handle so many writes which is why I went with new chips.

 

Can't tell how clean it is but looks good from here. Now for the fun part.. I coated the pads with flux before I went to solder. I was so worried I might pull a pad when I took the chips out but the hot air worked very well.

 

Good point; I would never run the JET on anything but XP when communicating. Its fine to analyze and modify files on Win10 but I would never to an upload from anything but XP.

 

Well fellers, I’m in the PROM burning stages right now. I added sockets to the boards (wasn’t going to originally, but I found some) and if an upload fails I’ll just pull the chips and try again. Getting a proper device ID on the blue/grey EEPROM has been a little bit of an issue but I think I have it figured out. Will keep y’all updated with my progress.

Check out this soldering, tiny USB-powered iron and no visual aids 😉

 

Oh yes, I’ll do the deep dig within Jet for the VIN edit. As long as I know it’s there somewhere I’ll find it.

Thanks all!

 

Looks much better than mine.. did. Some look a little light on solder from the photo though. Maybe just the angle.
Yep the chips are slightly different due to size (not physical) if I remember right.

Burn should take like 5 -10 seconds if remember right as well.

Yeah good call to solder in sockets. I never even considered not doing sockets. Kinda wish I had dribbled a little silicone on each one to hold in place just to be sure. But have had no issue thus far.

another thing I wish I had done is burned several sets just in case. All the time is in the setup and remembering the settings needed.

But I did build a spare so there is that. I just hate being helpless when things go wrong. Now you wont be as nervous on each JET write.

Did you not pull a copy of your config first before writing? Dont understand why you needed LT4 configs.

You should be on your way soon... big job when all is said and done including getting the damn pcm out and back in. Though I only have 1.5 arms so it is a little tougher for me (partially paralyzed rt arm).

 

I did pull a copy over a year ago. But my calibration configuration wasn’t stock. This LT4 has a bunch of mods and it was running rich, clearly. So not knowing what the factory baseline values were I needed to find them to see what would happen.

by the way, burning went peachy, no errors. I was concerned that I may have overheated the chips on removal and harvested a small handful from various scrap PCBs I’ve collected over the years. I never paid any mind to the little 32 pin flash chips until yesterday. Now I’m harvesting them like there’s no tomorrow!

Correct solder application means the outline of the leads can be clearly seen. A blob covering the joint prevents proper inspection of the bond. Trust me on that. I’ve done a little MIL SPEC assembly work back in the mid ‘70s.

My heat gun is not an official SMD heat source but with a small mod to the outlet I’m able to raise the temperature a little and focus it better on the joints needing desoldering. I didn’t have this mod when I pulled the two EEPROMs off the boards. That’s why I was concerned that I overheated them.

Here’s what I harvested from the big pile of boards:




...and here’s the pile. Note the two sockets in there somewhere...



Pardon me while I plug the chips back into the PCM and hold my breath while cranking the starter! 😬

 

Sounds good, your car. Hope it works out.

 

Well....................................

Just how particular is the firmware to matching a particular vehicle? My saved configuration had VATS disabled, this default LT4 configuration has it enabled I’m sure. I’ve done a VATS bypass resistor for MY original configuration and am willing to bet it doesn’t match what I just burned into the PROMS. She started, ran for a few seconds, then quit. Started again, ran even shorter, than quit. Started once more and immediately quit. Fuel pressure in the system was going away, just the same as when VATS is working.

I was hoping I could go down the road this evening on the just-burned files but it’s not to be. Have to risk burning my old calibration files in and hope there’s no app crash.

Stay tuned (ha. ha. ha.)

 

I addressed this in a previous post...

 

I did make an attempt to write my as-received-3-years-ago calibration files but only had my Vista OS laptop (again?) available. I first read from the PCM to test the waters as it were then held my breath and programmed my working configuration file. The write went roughly 50% then crashed. Out of time to play tonight but I know how to recover from a bricked PCM and will eventually win this battle. There’s an XP desktop machine that works and the XP laptop with a power brick around here somewhere. I’ll get it.

And I found the VIN editor I think, didn’t have to dig deep at all but that’s an experiment for another day.

Time’s up, see y’all later. Thanks again.

 

You really dont listen well. I guess some people have to learn the hard way.
A.) Virgin XP. Virgin means without all that crap I see you have installed on probably the most unreliable OS every released my Microsoft, AKA "Vista".
B). NEW flash PROMS. Dont cheap out on old PROMs you find laying around that might be bad or are now bad from the heat you applied removing them.
C). Solder consistently with a nice cover on each pin and use a VMM to test each connection before proceeding
D).Hi amp output charger with all accessories off.
E.) always read first (good job on that one anyway) However, it doesnt mean you have good connections on all pins.

If anyone else needs help on recovering PM me.. Im unsubscribing from this as I cant watch this any longer

 

Sorry to see you go. You’ll miss the grand finale. Some people, myself included, learn by doing things differently than just following orders. Mistakes are made, sure, but the experience broadens one’s horizons and gives more to draw on when a similar situation occurs. I learn by doing, not following. So... Thanks for the help, it’s much appreciated.

A) I have that “Virgin XP”, it just wasn’t available in time when I needed to use it. What’s the problem with trying my Vista box again? Flash was running in the proper compatibility mode. Since the first failure to write (and program going unresponsive) I disabled the only known antivirus program and tried again. What if it had worked? No, it didn’t but I was at least brave enough to try it.

B) The PROM burner verifies the write and there have been no errors. And the way the PCM acted after the reassembly seemed perfectly normal. I’d say the chips are fine. I tested all the chips for basic function that I desoldered (just for the experience, not to necessarily use them in my PCM) and except for two that weren’t listed exactly in the burner’s component definitions, all checked out. I didn’t even static zap any, my biggest concern.

C) You don’t cover pins with solder. That hides the view to inspect for correct flow and bonding. The contour of the conductors should be visible. When inspected after using a correct soldering technique there’s no reason to have to do a continuity check. Any defective solder joints are obvious due to proper soldering technique.

D) Battery voltage maintained over 12.4V. And what does that have to do with the flash program crashing? You fix one issue at a time, that’s the only way to know the cause of the failure and then move on. Using my “virgin” XP laptop is the first and most important thing to change. It’s the only error I’ve experienced so far so why point to other things needlessly? You clearly don’t know the proper way to diagnose a problem. A “shotgun” approach may get the basic job done but teaches NOTHING. That method of solving a problem can have an unnecessary high cost for a potential customer too. Repair shops fix things that way all the time and maybe you’ve been a victim of such practices. Not me.

E) Good communications has to be established first obviously. And wouldn’t the flash program complain with a communication or verify error if a chip pin had a faulty connection? Or wouldn’t the engine fail to run at all if a PROM had a bad pin? Recall that it did start and I claim it was VATS doing its job that caused the shut down.

If you want to leave, that’s up to you but I may discover something that could help others that hadn’t been discussed or even tried before. Maybe you’d even learn something new. Turning away isn’t beneficial. But maybe your ego can’t handle it. That’s my opinion.

My XP laptop is up and running. I was shocked to see a desktop picture of my LT4 and Jet installed. That was done well over a year ago but my inability to fix or find it a new battery pack caused me to put the old Compaq away. I’m ready to risk running it on AC power as that’s the next step here. The search for success continues...

 

what make and model laptop, there are lots of batteries on eBay

 

That’s an old Compaq Presario 1800 series. Says Series CM2050 on the bottom. Usually a search on Amazon will net decent results with blindingly fast shipping. eBay is generally slower and I had a time crunch to deal with.

But, check this out! —————->




SUCCESS!!! 💪🏻💪🏻💪🏻💪🏻

Because I knew my as-purchased calibration file ran (although rich), I uploaded it first and got that nice, loud exhaust note back again. Oh Baby how I missed you

The Compaq laptop did the job but not having the internal battery to act as a UPS had me a little anxious. Now with that success under my belt it’s time to try some alternate tunes, as was my original intent last Sunday night.

Can short video clips be uploaded here?