DI Module

[Chillidoggy]

If you’re bored and looking for something to do Alan, the 4-cyl D.I. Module is NLA, and unless @sailorbobhas found a replacement in the meantime, it’s a potential time-bomb.

[swindon_alan]

I think Derek is well on the case with that one Ian. Not sure I could assist much unless I could have one to take apart (as Derek wants to do anyway).

EDIT:

@sailorbob Have you seen this post Derek? Choice 2: add an internal jumper so you can use a GM DI module? This is probably not for this forum might move these to Stevens...

[Chillidoggy]

7 minutes ago, swindon_alan said:

I think Derek is well on the case with that one Ian. Not sure I could assist much unless I could have one to take apart (as Derek wants to do anyway).

Derek and I conversed at length on this subject. I think it ended up at a brick wall, never managed to get to the bottom of it. I also think there’s a need to split the casing to modify, but that’s as far as it goes. I did buy a new unit from the US, but it appears unless it’s Lotus specific, it throws a CEL.

[sailorbob]

Thanks to a LotusTalk forum member I have a faulty Lotus DI module to take apart. I've also bought a pattern part DI module to sacrifice to try to see if there are any obvious differences to their circuitry. I just need to find some time to get in there...

[Chillidoggy]

1 hour ago, sailorbob said:

Thanks to a LotusTalk forum member I have a faulty Lotus DI module to take apart. I've also bought a pattern part DI module to sacrifice to try to see if there are any obvious differences to their circuitry. I just need to find some time to get in there...

I still have the new D1927A. Let me know if you want it to split and test. 

[sailorbob]

Thanks, hopefully I won't make too much of a balls up learning how to get into one without destroying it to need another   😀

[swindon_alan]

Are they potted Derek? Or just have a nasty lid like the KH EBCs?

How to remove epoxy potting (assuming that the chips can all take a 100C "storage" temperature).

[sailorbob]

No idea yet, but they do have thin aluminium covers that look like they will crease at the lightest attempt to pry them off.

[Barrykearley]

32 minutes ago, swindon_alan said:

Are they potted Derek? Or just have a nasty lid like the KH EBCs?

How to remove epoxy potting (assuming that the chips can all take a 100C "storage" temperature).

The reflow temperature the circuit boards would have been assembled with would have been significantly higher than that. We used to routinely heat comms kit in a thermotron to artificially age cycle the equipment to eliminate premature failures.

[sailorbob]

The internals are probably very similar to the 6 cylinder module shown here https://www.diyautotune.com/support/tech/customer/gm-dis/

[tomcattom]

What's the issue in terms of the failure observed with these units? Is it a common failure I should be worried about on mine given the time its been stood about unused?

[Chillidoggy]

13 hours ago, tomcattom said:

What's the issue in terms of the failure observed with these units? Is it a common failure I should be worried about on mine given the time its been stood about unused?

The issue is if the D.I.Module fails, there is no direct replacement GM unit that we’ve found so far. There are any number that allow the engine to run (D1927A being one), but they all cause the ECU to throw up a CEL, which means that warning is lost to the driver for any other issues that the ECU might illuminate the CEL for. I have a list of modules that don’t fit somewhere, some people reported success with Isuzu modules, others said they didn’t work, but if Derek can get into the casing to see what’s inside, then that’s the best chance there is of solving the problem.

No, I don’t believe this is a common failure.