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Something isn't adding up here. Do you still have have a fuel pressure gauge hooked up? Do you still read 80# of fuel pressure? What does it read during these no starts, does the pressure immediately jump as soon as you turn the key or is it slow to build? What happens if you turn the key to on and just let it set for a few seconds? Will it start first try or do you have to go through a crank cycle first? If the fuel system checks out 100% then we're going to need to see some data file during the crank no starts to look for a culprit there.
I checked the fuel coming out of the bowl and it wasn’t foamy at all. Looked pretty clean. But I went ahead and dropped the tank anyway and cleaned out the screens. The pickup one at the base of the pump was very clean and the two tubed screens inside the pump housing weren’t that bad. I did notice one of the breather lines coming off the end of the tank was corroded and broken so I replaced that. It seems (maybe it’s all in my head) that it has a little more pep but nothing changed as far as needing to prime the system or it will just crank without fire. So I’m starting to think this isn’t a fuel issue. I will add that this whole thing started once the weather started to warm up. Could it be an hpop issue with my oil (delo 15w-40 with about 1k on it) being too thin or something? Starting to run out of things to check on the fuel end. Thanks
AS AN EXPERIMENT ONLY, try adding some 90wt to the crank case oil and see if it makes a difference in how it starts. If you have a pressure bleed somewhere in the HPOP system, then the engine will either start on it's own, or be much easier to get going when the engine is hot and thin due to the much higher viscosity oil. Don't get anything fancy, just the cheapest stuff you can find. If it makes a difference then you know where to look. My money is on a weak HPOP or badly bleeding injector o-ring.
Ok I can definitely get some readings on the psi during cranking to better see what’s going on there. And I’m not opposed to thickening the oil to see if that helps but first I have to ask… after reading around on here could my ICP sensor have anything to do with it? It looks like the stock, smaller one so it’s probably 23 years old and while it’s not covered in oil, there's definitely oil on/in it so I figured id ask. Thanks
Ok I can definitely get some readings on the psi during cranking to better see what’s going on there. And I’m not opposed to thickening the oil to see if that helps but first I have to ask… after reading around on here could my ICP sensor have anything to do with it? It looks like the stock, smaller one so it’s probably 23 years old and while it’s not covered in oil, there's definitely oil on/in it so I figured id ask. Thanks
A faulty ICP isn't supposed to be able to cause a no start but I firmly believe that just about anything is possible. Have you tried unplugging the sensor yet to see if anything changes? I wouldn't just replace the sensor because it's old, between the cost of a new Motorcraft sensor and the fact that even Motorcraft has started having stuff made in China, your original sensor might be as good or better than a replacement. Now if the data and testing show the sensor is bad then yeah time to rustle up 2 bills and make an order.
It’s been cooler here the past couple days so I was able to experiment with the crank so start problem in terms of the temp effecting things. I drove it for 30 min and when I shut her down it was only 60 degrees outside. I was able to restart it just fine without priming (it sat for like 20 min first). Later in the afternoon once the weather warmed up a bit I tried the same thing and it just cranked. I’m pretty confident the temp under that hood (so I assume the oil viscosity) is playing the major factor. So now should I start down that path of diagnostics and disregard the fuel path? And where to begin? I opened the hpop reservoir and can see plenty of oil in it but not sure of a next step. Any advice is greatly appreciated. Thanks
We need to see ICP, IPR DC%, injector PW, mass fuel desired, EOT, and RPM while the start attempt is going on. The ICP and IPR numbers will tell us if it's a hpo problem. If you're cranking and ICP doesn't get above 500# but IPR goes up to 64% then you got oil trouble of the high pressure variety.
my '02 Excursion with 15w40 did not like to start in low temps below 40*
it was bad enough that I put a Temperature controlled relay on the block heater, it turned on at 49*F
then if I gave the glow plugs at least 90 seconds after WTS went off, it would start and idle smooth.
next oil change, I went with 5w40 pure synthetic.
it now starts in 20*F weather w/o the block heater if I let the glow plugs warm up for the count of 100 after the WTS goes off
