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ECUflash 97 spyder gst black box and open port 2.0

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LilRedSpyder

Proven Member
62
11
May 2, 2019
Livingston, Louisiana
Ok I have a 97 Spyder GST that I’m slowly building and daily the car. I’ve scoured the forum and web plus read god knows how much but I cannot find anything that solves my specific issue.

I’ve already got ceddy mods and have the basics of the ecu flash. Can anyone tell me why whenever I swap to the black box the car starts, runs 3 sec and dies. Every. Single. Time... 🤯 I even have another black box that's a spare and when I plug it in, same thing, car starts and runs 3 sec and dies. No matter what I’ve tried it still dies every time. But if I hook up the stock ecu the car cranks and runs fine. It‘s getting old and I know it’s something so simple. I just cannot figure this out.

Help. Anyone. Thanks!
 
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Is the "stock" ecu the original 97 ecu for sure? Not a 95 or 96 ecu someone had put in there correct? The reason I ask is the later ECU's use a different CAS with an inverted signal so if your other ecu is an earlier one than the coils will be wired up backwards. Also, your black box ecu is not out originally out of a 2.4 spyder by chance is it? In that case the fuel pump trigger would be reversed.

Those are just 2 possibilities off the top of my head. But in general you need to be looking for a wiring, sensor, connection issue if it is trying to run but dies. As long as the flash completed successfully when you loaded Ceddymods there will be nothing wrong with the ECU. Especially if you have a second black box and it's doing the same thing. There is something different between the setup of the ECU you have and the black box.
 
Yes my stock ecu is the factory unit for the car. It’s a metal cased unit. The black box is out of a 98 gst or gsx I believe. Added a pic to reference seeing as how Im just scratching the surface of the tuning realm.

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What modification is that green wire for? It looks to be drilled through the case.

Is this modification done on your other black box ecu?

Was the car originally a GS that got an engine transplant? GST and GSX wiring provides fuel pump grounding through the black box ecu. GS cars use an auxiliary relay to provide the ground for the fuel pump. Those auxiliary relays do eventually go bad.
 
The wire you see is the phono plug that goes to the open port. someone decided to solder the wire directly to the ecu rather than add the pin on #79 I believe on the ecu harness.

It is not on the secondary black box. Only the one with the open port.

The car is a spyder gst. Was all factory when I purchased. Didn’t stay that way very long. Haha!
 
Well looking at those part number you posted you should be fine. Your OEM ecu is indeed a 97. You have a crank trigger CAS with the additional cam sensor on the head correct?

If that's the case there really is no reason that the black box shouldn't work the same as the 97 ECU. The black box ecu part number you posted is out of a 99 GSX so fuel pump trigger should be correct. Not sure where your problem would be. It is slightly concerning that they opened the case on that ECU and soldered right to the pins on the board. Nothing wrong with that if it was done properly but sure seems like extra work and risk to the board when you can just add the pin to the connector.

What is the part number on your other flashable ECU? Have you tried reflashing the factory unchanged version of CeddyMods to either of these?
 
Yes. I do have the cas on the head.
And I agree with you about the board and wire. I considered cutting it and just adding the pin. It’s not so difficult. And if you need it can be taken back out. 🤷🏻‍♂️ Just how my brain works. Idk about others. Here’s the second black box.
I did try to flash the factory ceddy onto it. It said flash was successful although it also says this…
And I have no idea what I’m looking at with the values.

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PM me and I'll email you the factory untuned version of CeddyMods with nothing changed from stock.

Then add the pin to the harness and flash that to MD359402 - 1999 GST ECU that hasn't been messed with.

After you flash post a screenshot of the whole readout from ECUFlash before you close it. Hopefully we can get to the bottom of this.
 
I just made a quick video of wha it’s doing. Also cut the wire on existing black box. About to locate a pin I can use from scrap wire pile and get it done.
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Here this. Still dies. I need a confirmation on the blue wire to be grounded to firewall. Is it a plug? Found 2, one blue, One black and side by side just above my heater core lines.

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