I recently purchased a 1992 F-150 with the 4.9 I6 from the original owner. I'm having an intermittent starting problem. It seems to start very hard when it's been sitting for a day or two. It cranks, just won't turn over. If I run it around town, it starts every time. Once running it usually runs perfectly with a very occasional "miss", never stalls.
In the past year, it's had: new fuel filter, plugs, wires, rotor, cap, starter motor, battery, and various other unrelated parts.
I've checked the fuel pressure (running and not running) and it's fine.
This problem is very frustrating because it's intermittent. If I crank it enough times it eventually starts, after I've run it a while, it will start flawlessly.
I'd appreciate some troubleshooting advice before I start throwing parts at it.
Anyone else had this problems.
Thanks!

 

I've been having similar problems with my truck, and I'm about 99% sure that its a corroded ground wire. I'd check all the wires/cables around the battery for corrosion. If they all check out, I'd say its an alternator on its way to the grave..

-Dave

 

Alternator is new within 2 years. It cranks fine, even the battery is only a year old. Just doesn't seem to want to turn over unless it's been running.
I'll check the cables though, thanks for the tip.

 

how's the timing?

If it's been advanced, it will do just that, it won't like to start when cold but when warm will do just fine. A little more advanced and it can cause a little miss.

 

That's something I haven't checked. I just got a timing light a day or two ago and haven't had a chance. I'm also waiting for a code reader to see if anything is stored.

 

my 89 does the same thing but it's a 5.0, new battery and alt. I checked and there's no codes, fuel pressure is good also.

 

It won't start at all now. Whatever is the problem it's gotten worse. This weekend I'm going to check into the ignition system. I'm hoping it's something simple like a bad coil. I'd hate to have to troubleshoot all the wiring harnesses.

 

it's easy to check for codes, goto www.fordfuelinjection.com, basically on the driver side fender you'll see the system diagnostic plugs, theres a seperate plug thats onlt a single wire, ground that one, then get ready to count blinks on the check engine lights...I'm horrible at describing things so the website tells you how and give you pics and everything too.

 

Did you happen to notice what the fuel pressure gauge did when you shut off the key? Did it stay put, or drop?

After trying to start it (when it won't start), quickly remove a spark plug and see if it's wet or dry. If it's dry, look for a TPS code. If it's wet, inspect the ignition.

 

I went through the troubleshooting of the Haynes Manual. The check for AC voltage of the PIP sensor output was out of range (way too high, like 16 volts and should be 3-8). Didn't changed when I unplugged the ECM module.
I am probably just going to get a reman. distributor instead of trying to change the sensor.
Thanks for the help!