How do I open a 96 GTS PCM?

[Red Shift]

The #7 injector driver got burnt out on my PCM. I want to open it and see if there is anything visible I can fix (broken solder joint, blown up piece of the circuit...). I took out the 7 screws on the box and it's still like a solid piece of metal!

 

[Red Shift]

I learned the following:

They're pumped full of a urethane resin. Without a dissolving solvent you'll destroy the pcm getting it apart, ruining your core.

Doesn't look like I'll be getting in this one.

 

[CPPRHD265]

Ugh, that blows. I wonder if it's to protect the PCM from vibration etc, or to protect proprietary design of the board?

 

[Red Shift]

I think they can be repaired by people with the tools to dissolve the insulation. The urethane is probably for protection from vibration, heat and moisture.

 

[Tom F&L GoR]

An electronics **** might be able to use another injector driver as a signal, not an amp draw, to trigger a ground switch of the same duration. It means injector 7 would always do whatever injector 3 did (or whatever you pick) but just fractionally later. Believe it or not, I think injectors are intended to fire at closed valves because the sudden blowback upon intake valve opening and then rush into the cylinder provides better fuel-air mixing that shooting through an open valve. So your target timing can be slightly off from OEM and still run fine. It already gets the 12V, so it's just a switch. Sounds so simple to a mechanical engineer, huh?

 

[Red Shift]

I'm actually doing that right now Tom, another ME in the building, haha. I have injector driver #8 running cylinder #7 & #8. They have the same timing on the firing order, so it was an easy splice in.

I'm concerned about causing the driver to fail with two injectors on it, or possibly changing the signal to the injector. A smaller concern is the fuel adaptives will pull the 1 left bank cylinder along with the right banks closed loop operation.

 

[GTSnake]

They're potted to protect the components from corrosion. I don't think the PCM is a serviceable item. If you know there is a short or failed component on there just replace it. It's much easier than trying to take it apart and repair it.

 

[Tom F&L GoR]

I'm actually doing that right now Tom, another ME in the building, haha. I have injector driver #8 running cylinder #7 & #8. They have the same timing on the firing order, so it was an easy splice in.

I'm concerned about causing the driver to fail with two injectors on it, or possibly changing the signal to the injector. A smaller concern is the fuel adaptives will pull the 1 left bank cylinder along with the right banks closed loop operation.

You'll have to assess the risk, but since they are "merely" switches, it is a duty cycle-amperage question. Duty cycle (% on time) is same, but amperage is double. Can probably find amp draw of an injector somewhere. Wonder if some tuners that have replaced OEM injectors with larger ones would know if they draw more current. You can start to build a case where it might actually work for some time, or at least in relative mental comfort while you look for a permanent replacement.

 

[EllowViper]

So that '98 PCM I sent was AFU as well??

 

[Red Shift]

So that '98 PCM I sent was AFU as well??

Sent you a PM. I swapped it in last night and will test the outputs. That will show if anything was damaged. I will replace it/repay you if any damage happened.

Really ***** if TWO PCMs got fried.