Starts fine the first time, then won't start.

[Brian1973]

1991 Ranger, almost 200k miles - Initial start in the morning and it fires up within a couple cranks.... any other time during the same day whether it has sat for 5 minutes or 2 hours, it will not turn over without giving some gas pedal.... Seems the longer between starts it may start a little easier but it definitely starts fine the next day. Seems an ongoing issue that has possibly worsened over the last few years. If I don't give it some gas pedal (yes, it's EFI, I shouldn't have to) it will just crank and crank. I have replaced the fuel pump and filter in the last couple years, I have swapped out the coil and put a new ecm. New wires, rotor, distributor cap. I did a check on the IAC valve after a recommendation from a member here and that seemed to pass fine. Only other thing I can think is to put in a new distributor?

 

[Eddo Rogue]

fuel pressure regulator? Spark plugs? My ranger hated NGK's, loves the autolites....

 

[Uncle Gump]

Sounds like leaky injector(s) to me. Does it huff some black smoke when it actually starts after sitting for a bit?

 

[Brian1973]

New double platinum Bosch plugs in May 2020 as well as wires, rotor, distributor cap, ecm. No change in starts. FPR was replaced with a 1992 engine swap due to a failed FPR and hydrolock in 2010 (so it's not THAT old, but aftermarket so who knows) . Wouldn't I notice other issues with any of these other ideas? Injectors etc? FPR is easy and cheap enough to just try another one but wondering the science behind the possible issue with FPR? Previous to FPR hydrolock I would get fluttering when accelerating at highway speeds. Rubber diaphram malfunctioned causing engine flooding with fuel :-( I do not notice any black smoke when it first starts but will pay closer attention to the side mirror and monitor closer. Truck runs great other than these starts after it's been running. Luckily the battery is good! crank crank crank.

It certainly feels like a fuel issue as it gets resolved sorta by pressing on the gas pedal. I sorta feather it, pump it in and out a little. Probably not important but almost feels like it needs to be pumped a little because just pushing down a little doesn't get it to turn over. Will try to pay a little better attention to what I'm now just subconsciously doing. Been doing for so long and this isn't a daily driver.... I was thinking maybe something in the distributor electronics and the pedal being pushed does something with the timing? Speaking of which I guess I will double check the timing too. Still weird how it starts fine the first time and then seems to be starving.

Really thought the issue would resolve last year with a fuel pump replacement although turning the key and priming it didn't help.... Then the heat issue affecting the ECM seemed reasonable and thought a new ecm would cure it. Nope.... Still searching!

 

[Eddo Rogue]

Mine didnt like bosch plugs. Autolite or Motorcraft are the only ones it wont run crappy on.

 

[Uncle Gump]

Would leaky injectors cause a drivability concern... of course. However the same could be said for a faulty FPR. Pop the vacuum line off the FPR and see if there is fuel present. There should never be fuel at the vacuum reference port on a FPR. If there is... replace it. Then test fuel pressure... and see if you're within specs. Also see if fuel pressure holds after you shut the engine down. If the pressure begins to fall after shut down... injectors are most likely leaking.

Next time you try a hot start... hold the accelerator pedal all the way to the floor. The will send the ECM into clear flood mode. The ECM will then stop pulsing the injectors during crank to clear a flooded condition. The engine should start perhaps much quicker then it does with the current process you are using with the accelerator pedal.

As for the Bosch plugs... if you brought the vehicle to me... I wouldn't do anything before those plugs were in the garbage can and the proper Motorcraft or Autolite plugs were in the engine. This is coming from a firm believer in Bosch plugs... I've literally sold and installed thousands of them. They have their proper place and work extreme well... but that place is not in a Ford engine.

 

[rubydist]

I have had that issue with vehicles that had leaking fuel injectors. When cold they will start fine, and run fine, but any hot restart will result in flooding and a hard to start condition. Sometimes a few tanks of fuel injector cleaner will make it okay again, and sometimes the injectors need replaced or professionally cleaned.