I've had this strange problem off and on for years:

If I drive my Ranger a short distance and stop for gas or something, say a 5min drive, then when I go to start the car it will not immediately start up. It will take a few tries, sometimes I can give it some gas and it starts, or i may have a wait a min or so to try again. Once it starts it then rough idles until I rev it up and then its fine, unless I stop and turn it off a short time later. If I do that it starts up fine but rough idles for a min.
This only happens about 50% of the time, and only after a really short first drive. It seems to happen a little more often in hot weather. The car has stalled only once, it was a few mins into a drive.

The truck also will rough idle sometimes, like a bit of a shake, when I go to start it up after a long drive of an hour or so. Again, seems worse on hot days.

This has been going on for years and mechanics can't seem to pin point it. I finally took it to a Ford dealer but they just said it needed new Spark Plugs and Wires, which I replaced myself and that hasn't helped. I've also cleaned the throttle body, checked the PCV, and replaced the fuel filter.


Do I have any code reading options since there isn't a check engine light on? Its a late 95 so OBDII should work.

 

I got a similar problem, it almost starts after a short drive, then I have to floor it and crank it, (I guess it flooded out) then it will start. It can be 0 deg outside and will start right up when cold. I wonder if by chance the engine coolant temp sensor is reading lower than it should be and the pcm thinks it is cold and dumps more fuel than necessary and floods it out?

 

Welcome to FTE. This is a great site for all things Ranger.

We can help but first we need more information about your truck. What engine does it have? How many miles are on the truck? Is the check engine light on? What brand of plugs and wires did you install? Our rangers are partial to Motorcraft plugs and wires.

You may have a dirty MAF (Mass Air Flow sensor). The IAC (Intake Air Control valve) may be dirty and sticking. If the check engine light is on, take your truck to an auto parts store (Auto Zone, O'Reilly's for example) and ask them to read the codes. Then post those numbers haere and we can give you more specific suggestions.

 

I'd take it in and see if you get any codes anyway - it is possible to have codes stored without the CEL being lit.

 

Sorry, I forgot to add some info-

Its a 1995/4.0L/XLT/RWD. Its got about 160K and I installed Motorcraft plugs and wires(I read warnings about using others.) The plugs I pulled out were from the previous owner and they were some weird "Split Fire". Couldn't be helping!

I'll try to see if its throwing any codes. CEL isn't on. I haven't checked the MAF, I did recently clean out the throttle body and found it without any dirt or grime.
It does seem like it would have to do with a thermostat or something not getting hot enough to send enough air.

 

With that number of miles on your truck, you may have one or two dying or dead O2 sensors. It would be worth checking them out.

Also, you may have some carbon accumulation in the cylinder heads. Go to the Tech Info at the top of the index page and look for the procedure to clean out the carbon.

 

Is there a way I tell if that is it? Bad 02 sensor turned on Cel in the past.

 

So finally took it in to see my mechanic, who is nice enough to check codes and stuff for free.
No codes being thrown around and he drove it around for a few days and said he couldn't get it to stall or rough idle after cranking. He did say the fuel injectors could prolly use a cleaning and that could be the source of my bad mileage and loss of power. He figures the starting problem is a bad idle air control valve and says it not worth replacing until its dead.
So I had him use to pro kit to clean all the carbon and junk out and now its driving really well, power seems better, and its not doing that stalling thing after short drives...Until....

Its 1:30am and I can't get the car to start right away. It takes like 4 tries over the span of a few mins and I try to give it gas each time. Finally it starts and i can breath again...

So I'm sorta back to square one...Keeping in mind that I've been having this problem for a few years now and I can't honestly say its really getting worse, is it ok to just wait until the valve totally fails(If that is the cause of my troubles), and if it does will I be stranded somewhere or will the car just not idle/crank well?

 

Where are you at on routine maintenance - plugs, wires etc? If the malfunctioning IAC is still acting up, how much longer do you want to put up with performance and starting problems? Getting stuck in the wilds somewhere and having a big towing bill will cost you a whole lot more than spending some money on a new IAC valve now and getting the assurance that you have taken care of that problem.

 

Your right on all counts, but is there any way to test the IAC? My maintenance is pretty good, the truck is just getting to the age when mysterious and hard to fix problems start sneaking up.
I'm pretty sure a vacuum leak isn't to blame, so doesn't it have to be the IAC?