I have started to have starting problems. The battery is good and the starter is good. It will start almost first time every time when clod after 12 to 24 hours. After that it gats harder to start. The engine has 306,000 miles on it and funs great! Once you get it started!
What do you mean 'harder to start" ?? You didn’t say what engine but I’ll assume a gas V8.
Long crank times? If that is the case, I’d bet the fuel pressure is bleeding off after 24 hours and your fuel pump needs to run a bit to pump it back up. You can test this by turning the key ON, listen for the hum from the electric pump, turn OFF, then back ON 3-4-5 times and THEN turn to crank. If it fires right up, you have a small leak.
Either an injector (or injectors) is leaking or the fuel pump back-flow valve is leaking or possibly the fuel pressure regulator is leaking. But not much. I’d throw some Techron fuel injector cleaner in the tank and see if that clears it up. With 300K on the clock, if the pressure regulator is original. I’d replace it ($26) as the next step. Fuel pumps are cheap but difficult to get to. I can’t imagine this thing is on the original pump. If it is, just replace it.
I have a six cylinder, but I understand what you said. I know my truck pretty good and I keep a mental track of things it is or isn’t doing. I looked up the pressure control on line and I think I found it in my truck. I haven’t tried the 3 - 5 times with the on-off and listen to the pump sound, which I hear all the time when first starting. It’s been sitting over night and I’ll start it up the way I’ve been doing all the time. Then when it gets warmer from going several miles, I’ll try it the 3-5 way and see what happens and then go from there. Hope it works! Love my truck!
How did you confirm those assumptions?
I ask because this kind of troubleshooting is easy to mess up if you go on assumptions based on the age of the battery and/or the age of the starter rather than physically testing them.
One of the most durable engines Ford ever built. Nearly bulletproof.
I know it’s been a while but I’ve been busy. Since you told me a trick to starting my truck it has worked pretty good. So Next week I’m having the pressure thing you mentioned replaced along with any hoses that are connected to it. I’ll let you know how it goes.