I'm working on a 1997 4.0 ohv and it has a hard start condition on first start up. any after that it will just be a crank no start condition unless you hold the gas pedal to the floor. Replaced the camshaft actuator, plenum gaskets, coolant temp sender and thermostat, fuel pressure is normal. Any advice is welcome

 

Since holding the accelerator to the floor will get it to start, that suggests that you have a flooded condition. Holding the throttle wide open (WOT) puts the PCM in "clear flood" mode and shuts off the fuel injectors.

If you changed the coolant temp sender rather than the sensor, you changed the unit that controls the gauge rather than the one the PCM uses to adjust the air/fuel ratio.

-Rod

 

I replaced the sensor that is directly under the throttle body, the connector had 2 wires going to it. I was always told that the sensor for the idiot light was the one wire sensor that wasn't touched

 

Both the sender and the sensor are in about the same area, but if you replaced a 2-wire sensor, then it sounds like you got the correct one. That's actually the sensor. The 1-wire device is the sender, and "sender" is what you typed in the original post.

If you haven't already, you might check the coolant level to make sure there isn't an air pocket that settles to the top of the engine, but I'm doubting an air pocket would cause a hard cold start since the sensor would likely be at the same temp as the air and the coolant....

Have you checked to see how quickly the fuel pressure drops once the engine is shut off? Maybe you have an injector or two that is leaking and filling a cylinder with fuel.

-Rod

 

Yesterday after replacing the camshaft actuator I started it and got 4 new trouble codes, misfire cyl 1, misfire cyl 4, o2 b1s2, and an ignition coil code I can't quite remember. Fuel pressure after shut down if I recall dropped pretty quick. I ran that test last week so my memory is a little foggy

 

I remember my fuel pressure results better now, while running it was about 30psi at shut down it would actually jump to 40 and remain there til tester was drained. This test was taken off of service port on the fuel rail