Intermittent crank no start, electrical/fuel related?

Okay, thank you, I'll try and check fuel pressure this week.
-S.R.

Hi Joe,

I am going to test the fuel pressure and replace the fuel filter today. The car probably won't start on its own, would it be okay rig up fuel pressure gauge then get it going with starter fluid to measure fuel pressure at idle? Where are the vacuum lines located? Also, I was wondering if I need to bleed the fuel lines of air after doing this, or if the system priming will do that on its own. Thank you so much.
-S

Okay, thanks so much, I tested fuel pressure today and replaced fuel filter.
Fuel Pressure > I checked fuel pressure inline after the filter and had it jump up to 40/45 when it primes, then start dropping. I tried priming a number of times and pressure continued to jump to 40/45, then fall at a rate of between 0.5-4 psi/ sec. While cranking pressure jumped around 45/50 and stayed there while cranking but truck would not turn over. The truck would not turn over with starter fluid in the intake. Replaced fuel filter and it was still not starting but did not test pressure with new filter.
-FPR - What type of issues will failing fuel pressure regulator cause? It is tucked behind intake manifold and hard to get to, are there ways to test it that don't involve removing manifold? Also - I didn't see any pressure test valves on the fuel rails, are there any on this car?

Camshaft Pos Sensor > After cranking car and not being able to get it to turn over w starting fluid, I checked codes. Had 1 code - PO 0340 Camshaft Position Sensor A (Circuit Bank 1 or Single Sensor). I have had this code come up once before, after crank no starting (due to faulty kill switch) a while ago. I tried cranking while watching RPMs and realized they are at 0, not jumping at all while cranking. Camshaft Pos sensor is in the distributor, 12V constant and ground to Distributor/Camshaft Pos sensor tested good. Would need to do more testing to see if camshaft pos sensor is producing correct signals. Are there any other diagnostics you would do relating to camshaft pos sensor and distributor?

Thanks for taking the time to read,
-S.R.

Okay, thank you. I'll check live RPM data while cranking. What does it mean if there is/isn't live data? Are there other diagnostics I should go through to check Crankshaft Position Sensor? I'll also try and pull a spark plug to see if it's flooded. Thank you!
-S

I get live RPM data stream while cranking, 0 on dash tachometer. I'm going to pull the cap off the distributor today and see if it looks like any bearings have failed in there.

Okay, yeah, live RPM signal was good just nothing on tachometer. I opened distributor cap to see if it looks like its dusty or had a failed bearing like I've seen in some YouTube videos. The optical timing disk looked clean and there wasn't too much dust or debris in there. I would like to test the camshaft position sensor more to see if it has the 120-degree REF signal, as well as 1 degree POS signal. I still need to figure out how to turn my crankshaft by hand to test this though. I don't have the right tools to pull my spark plugs at the moment, when I do pull them, I'll check for spark but may not be able to pull all 6. Do you know if the ECM is using multiple sensor inputs to calculate signal to tachometer, if so is one of them the Camshaft Pos Sensor in addition to Crankshaft pos? Thanks so much, and happy New Year!
-S

Okay, yeah, I can do that. Do you mean open the distributor cap and crank the engine from ignition? Or turn by hand? Thanks so much.

Hello, sorry I was traveling during January and not working on my truck. The distributor rotor is turning. Truck still crank no starting with no dashboard RPM data. Do you have any information about the sensors that provide RPM data to the dashboard VS to live data? I also might check injector pulse with a test light.
Thanks
-S