Why was there no thrust from the engines in the TACA Flight 110 incident?
To generate thrust, engines need fuel and air: a spark will ignite fuel (by getting heat, above the ignition point), which burn with the oxygen in the air.

On this (and other incidents), together with air, also rain (and hail or snow) in the engine, so the spark is not enough to ignite the fuel, and so the engines stop working. So, this is the important factor: air and rain enter in the combustion chamber. It is not a problem of fuel distribution, it is just a problem of not being able to ignite fuel. [On car you have air filters, and air compressors, but also a very different cycle compared to jet engines]

The continuous restart means that the engines will continuously add some sparks, so that if ignition fail one, at next turn the the ignition should start again.

The spinning means literary: the engines were spinning, but this doesn't mean they can get enough energy. The article in Wikipedia tell us that they never reached IDLE power. I think the problem is that rain has blocked many of the sparks in the engines, so the engines ignited only some time, enough to get the engine spinning, but not enough to get power.