88 5kq - Intermittant Hard Starting

[SJ]

Symptoms:
88 5kq - no turbo - NF engine
Symptom: Intermittant Hard Starting under cold and hot conditions.
Majority of the time, the car starts up fine . .cold or hot.

Update:
At my last post, I replaced the O2 sensor and installed a gutted cat. The
results were very low O2 readings at idle. Sensor started working at revs
over 2000 RPM.
I put in the original cat, with new the new O2 sensor. Results are same as
above.
I put in an old good Bosch sensor in the original cat. Results are same as
above --> O2 sensor will start fluctuating normally only when revs are at
2800 RPM and above. At 2500 RPM the readings become slow and erratic. At
revs down to idle, the O2 sensor voltage does not fluctuate and drops off
till it reads almost 0 volts.

I'm suspecting a lean mix up to 2800 RPM. Maybe a vacuum leak, although I
checked for that and didnt find anything.
My other suspicion is low fuel pressure, which I need to test.

I'm making a fuel pressure gauge hookup.
What I need to know is what kind of adapter is needed at the lower chamber
test port? This is the port behind the fuel distributer (next to fender).