Hi,

I cannot say that the fuel injection of the LH 2.4 is unreliable in itself.
It's more likely the peripheral things or things connected around it that cause most of the issues.

A fuel pump relay or a faulty CPS can start things off for a headache!
1989 was the first year for a CPS. Flakey shielding or insulation around the wire is one cause or the probe goes out of calibration for the ICU. The ICU is fairly bulletproof from what I have read. Windshield wiper water drips can cause headaches!
A sensor, like engine coolant one can be another cause.

In the later nineties they started messing around inside the instrument cluster speedometer giving off information to the ECU for idle or movement or both.
Speedometers, I'm finding out, are year specific in some cases.

The LH 2.0 and LH 2.2 had wiring harness problems out around the engine. That was not the fault of the fuel injection system unless you want to point to the engine bay ignition unit and THAT was back to the wiring connector, to it!

So trying to catalogue or categorize a system worse than another is not realistic.
Each have their own technological advancement, with costs, as a weigh-in factor, for that improvement.

So far, I have been very impressed with Bosch products. Considering, for all the years that have gone bye, it just proves my point, to me!

I Hope this was an answer you were looking for?

Phil