240sx Wont start after it's been running - common issue?

[Winddrifter86]

Before i get pelted with attacks saying i should have searched, I did. But there's no direct answer and i'm limited on spending money.

It's a 1991 240sx with a KA24DE. If i go out there right now, it will start just fine but shakes alot. I can let it run for an hour and drive it around the neighborhood too! But the moment i turn it off and crank it it just cranks and cranks.

I stayed up lastnight trying to diagnose and here's what results i have.

Spark Plug Wires, Cap, and Rotor were replaced last year with napa ones they are sparking against a ground when cranking

Coil and plugs were replaced last month. Plugs spark fine against ground.

Fuel Pump Harness Connector. I checked that terminal a and ground has continuity and Terminal c of the harness has continuity with terminal 3 of the EGI Relay.

Checked Fuel Pressure Regulator and Carbon Canister


Looking on the forums I saw a lot of similar complaints some were solved some were not. Some solutions were..

Distributor (Disconnecting wire 4 from the cap makes it run a little smoother less shaking. Disconnecting wire 1 doesn't affect it at all. 2 or 3 it runs harsh)
Cleaning Fuel Pump Regulator
Coolant Temp Sensor (Also After running for at least 1 hr lastnight the coolant temp gauge went up only a little.
Throttle Position Sensor
Fuel Pump (We did smell fuel from up front but cranking that much with no combustion it's a given)

Please help me. I have a pretty good knowledge of cars and I can test ALMOST anything you throw at me. I'm just not too familiar with this car. I just bought it off of a friend who needed some cash.

I do own a FSM so I can look up pages and what not as well..

Thank You for any and all input given,
Scott S.

[Winddrifter86]

Also. on youtube go to /watch?v=2YFV19GdGY8 it's EXACTLY what happens but i haven't tried unplugging the EGI Pump relay to start it. and If I did what would that mean?

[Hijacker]

Have you check all the vacuum lines to make sure there's no leaks? And double check the intake plumbing couplers to make sure none have come loose. Lastly, has the coolant sensor (2 prong) been changed? If it not, it's a $20 part and given you're having a temp dependent situation, I would toss in a new sensor to ensure that's not the culprit.