Starting Problem

[jjm0001]

I had a problem trying to start my 2000 explorer sport today after work. The car had been sitting for like 8 hours all day and it's like 50 deg outside. Turn the ignition key, acted like it was going to start for a second, but didn't. I tried again, cranked for like 5-10 seconds, the engine cranks, but it would not start and run. I tried a couple more times but no luck. So I waited about 10 minutes and the same problem, won't start. Opened the owner's manual (since I had nothing better to do) and it says if below 10 deg F, you can depress the gas pedal to start. I know it's not that cold, but I depressed the gas pedal to the floor and let go. Then I turned the key, and it started for a second, then died. So then I held the pedal to the floor, cranked it and it started right up, running a little rough. I held the pedal at about 2000 rpms, and when I let off of the pedal it acted like it would stall out, so I held the pedal for about a minute. Then after a minute, the engine idled fine. So it seems to me that the engine wasn't getting gas to start. The car has 31,000 miles on it! I can't believe this thing wouldn't start right. I read some previous threads on hard starting, but I don't know if I have the same problem. Does the computer on this model record the source of this type of problem, even if the check engine light doesn't light up? Can a Ford dealer read problems like this off the computer memory? Any ideas or experience with this problem would be appreciated.

 

[dogfriend]

You were getting too much gas to start. When you held the pedal to the floor while trying to start, you gave the PCM the signal that the engine was flooded. It responds by cutting off the injectors while cranking until it recognized that the engine was starting, then it goes back to normal operation.

You might have a problem with the IAC (idle air control) valve. It is supposed to let bypass air into the intake manifold during starting. Do a search on IAC to find lots of info on this. Here are a couple of threads:

Dead Link Removed

Dead Link Removed

 

[jjm0001]

I think you misunderstood my problem. I didn't "flood" the engine when I first tried to start it. I only turned the ingnition key to try to start the engine. After this didn't work on several attempts, Then, I tried pressing down on the gas pedal. Then it started.

Now I read some history on this forum about the IAC valve, or whatever it is. It seems that this IAC valve thing is blamed for all different types of idle, stalling, drivability and starting problems. My vehicle is still under warranty, but this problem does not repeat every time, so I was wondering if anyone has had the same exact problem and knows the cause so I can tell the Ford dealer to replace this part.

Plus, this type of failure makes me wonder if I'd be wanting to take this car off road out in the middle of no where and have some stupid $0.02 IAC valve leave me stranded. Great design Ford has!

 

[dogfriend]

You may not have done anything to "flood" the engine, but I believe that you were getting too much fuel regardless from your description. The clue to this is that you were able to start by holding the pedal down to the floor. The PCM (aka computer) interprets a wide open throttle signal from the TPS (throttle pos sensor) by cutting off the injectors to allow raw fuel to be diluted from the incoming air.

The second clue is that you needed to open the throttle to keep the engine running after you got it started.
The throttle does not control the amount of fuel going into the engine. The computer controls this by adjusting the pulse times of the fuel injectors.

The throttle controls the amount of air going into the engine. The reason I pointed you toward IAC problems is because that is one of the functions of the IAC; to regulate bypass air during starting and idling.

The reason that the IAC gets "blamed" for a lot of these problems is because it is a common problem on Ford vehicles. It can also be a perplexing problem because it can be intermittent (like in my case) and won't light the CEL or set any codes because it does not feed back to the computer.

Also, the IAC valve costs between $60 -70