1996 Jetta difficult start and wont stay running. Sensor p

Hi,
I have a 1996 Jetta GL, 2.0 L with 120,000 miles on it. It just recently got a new clutch and about a week after that it started having problems.

At first it wouldn't start, I replaced the fuel pump and the fuel pump relay, then after a lot of cranking it finally started but when I went to drive it it seemed to randomly shut itself down. I could never get further than a block and it would do this. It idles great and when I wasn't moving the engine would rev up no problem

Then I changed the fuel filter thinking that it was restricting the fuel flow and now it starts, (very hard and a lot of cranking, ) once idling it is fine, but when I suddenly give it gas it dies, a relay clicks and it takes about 2 minutes of cranking to start it again. If I gradually accelerate it works fine. I was wondering if maybe a sensor could be to blame or if you all have any ideas.
The other thing is that while I am trying to start it it seems to fire very briefly every time just as I release the the key to give the starter motor a rest. It's not enough to start the engine but I can hear at least one cylinder fire. Thanks for any help!