Ignition does not shut off truck after EBL Flash II install

[Wolvrine82]

Good afternoon. I have just installed an EBL Flash II in my 89 GMC C2500 and the truck will not shut off with the ignition key. The truck has the 5.7 with a TH400 transmission. Has anyone else encountered this problem? Thanks in advance for any advice.

 

[PlayingWithTBI]

Has anyone else encountered this problem?

Nope. Your Ignition Switch should shut off the injectors and the coil.

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[Wolvrine82]

The truck shuts off normally with the stock ecm installed. The only change has been the installation of the EBL ecm.

 

[PlayingWithTBI]

The truck shuts off normally with the stock ecm installed. The only change has been the installation of the EBL ecm.

Are you running the same ECM with the EBL upgrade? Like a 1228747 (for the TH400 trans) or is one a different PN like a 1227747 (for a 700R4)? Have you talked to [email protected]?

 

[Wolvrine82]

The truck had a remanufactured 1227747 in it when I purchased it so that is what I sent to have upgraded. I tried emailing bobr twice and have received no communication from him since delivery of the ecm. That was when I posted here and on gearhead-efi hoping for some advice.

 

[PlayingWithTBI]

That was when I posted here and on gearhead-efi hoping for some advice.

Yeah, I saw your post over there. You may wanna try here, he usually haunts this site. HTH

www.thirdgen.org/forums/diy-prom/356351-tuning-ebl-105.html?ispreloading=1

Tuning with the EBL - Third Generation F-Body Message Boards

DIY PROM - Tuning with the EBL - Hey can we start a thread for EBL tuning. The EBL thread is grown rather large and was pre release. All of us that are using the EBL could share our results and tweaks. RBob would have a place to vist on his own time and help those that need advice using his EBL...

www.thirdgen.org

 

[Road Trip]

Nope. Your Ignition Switch should shut off the injectors and the coil.

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I would be curious as to what occurs if you go to shut the vehicle off, it stays
running, and then you pulled the fuse that's circled below:

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My understanding is that once this fuse is pulled then the ECM will shut down.

Meanwhile, the fuse at the top (INJ A) provides power to the 2 shower nozzles,
so +12v sits on them, but no current flow (no work) occurs until the ECM
grounds these circuits. (A handful of milliseconds at idle, near continuous
at full throttle.)

In other words, the diagram above can visually mislead a little, making it look like
the ECM has 2 sources of operational power. But the reality is that the ignition
switch (via the 10A ECM/IGN fuse) is how the human communicates to the ECM
whether to run or not.

Check this page out from the '89 FSM. Look for the text next to the arrow:

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Of course anything is possible, but I'd want to prove that the power is appearing and disappearing at this fuse
as you would expect when operating the ignition switch. IF the ECM stops running when you pull the fuse,
then it is operating as expected...and now it's time to verify proper ignition switch operation.

But if you pull this fuse and your GMT400 continues to run? Hmmm -- either I don't understand this
circuit properly, or you do have an ECM issue where you need to talk to your tuner?

Just saw the above in the '89 Fuel, Emissions, & Driveability manual and wanted to throw it out
there for a proper kicking around. :0)

Consider giving this a try and see what you get.

Happy Hunting --

 

[Road Trip]

The truck shuts off normally with the stock ecm installed. The only change has been the installation of the EBL ecm.

PS: I'd be really interested if pulling the circled fuse on the previous diagram does affect the original
ECM as expected, but when you swap in the EBL ECM it continues to run with the fuse pulled?

This would definitely finger the EBL ECM for me. There is something strange about all this.

 

[JDGMC]

Good afternoon. I have just installed an EBL Flash II in my 89 GMC C2500 and the truck will not shut off with the ignition key. The truck has the 5.7 with a TH400 transmission. Has anyone else encountered this problem? Thanks in advance for any advice.

To clarify - it shut off normally before you shipped your ECM out for the upgrade and you do not have another ECM to rule out the upgraded ECM? If that’s the case a few questions:

1. Which accessories are still powered when you turn the key off?

2. Disconnect the ECM and check the plugs/connections - square and tight - snapped in.

3 How long did the truck sit before you installed the upgraded ECM?

4. Any wire work - tapped power wires for stereo, trailer, etc.

Hopefully, you have already solved the problem, but just in case.

 

[termite]

2. Disconnect the ECM and check the plugs/connections - square and tight - snapped in.

4. Any wire work - tapped power wires for stereo, trailer, etc.

Maybe @PlayingWithTBI knows the answer to my question along the lines of what I quoted above.

Any pins need moved to install the EBL as compared to OE ecm?