Cold weather + hot engine starting problems

ford
ranger

#1

2006 Ford Ranger FX4 - 124k. I’ve been having problems starting my truck after I drive it — get it to the normal operating temperature — turn it off and try and start it 15 min. to 2 hrs. later. This only really happens when it’s cold (usually below 40 degrees).

When the engine starts, it will sputter a bit and stall. Sometimes it will take 2 to 6 tries before it starts and revs properly. If I start the truck in the morning, it starts great. If I leave the truck to cool off, once again it starts fine. It’s never left me stranded and the truck runs like a top (no loss of power, mpg, etc.) other than this problem.

When I brought it to my mechanic last winter he thought it was the fuel pump going bad, but wasn’t 100% certain. I decided to wait and see if it went away with warmer weather, and sure enough it did. But with winter in full swing, the problem has returned.

Has anyone ever had this problem, or have a solid idea of what it could be? Thanks for the help!


#2

Solid idea? No. Complete Guess? Yes. lol … Seriously, cranks but doesn’t start is usually either a fuel or spark problem. This one sounds more like a fuel problem than an ignition system problem. Next time it happens, try holding the accel pedal all the way to the floor while cranking and see if that makes it start better. If so, that means the engine is getting flooded somehow. Leaky fuel injector is one possibility. If that doesn’t help, a fuel pressure test is probably the next step. Or a basic spark test at the spark plugs.


#3

Another thing to check is the plug wires if they went bad or not.


#4

A good scan tool will show the inputs from various sensors and one of them is likely at fault. The engine coolant temperature and intake air temperature would seem the most suspect in this situation but in order to recognize the faulty system you must become familiar with the parameters of the system when it does start. As an example consider that if the intake air temperature sensor signals that the ambient temperature is 99F the computer will only feed the engine an extremely lean mixture at an extremely low idle setting. If the actual temperature is 30F the engine is not likely to start in that situation.


#5

Thanks everyone! It sounds like I need to get my hands on a good scan tool to see what’s going on. Appreciate all the tips — I’ll report back with what I find.