Today I had my truck towed to mechanic shop for repair. When it got there it cranked up no problem several times, so the mechanics are scratching their heads.

It started a week ago, for the first time. I drove home after work, no problem. Once at home, turned ignition off, after about 20 minutes I had to leave again, but the engine won't start up. It cranks but will not startup. Finally gave up, and next day, it cranked and started up no problem. But on the way to work, about 10 minutes into road at 40 mph, engine died suddenly. I pulled over and again it cranks but will not startup. I gave up and sat there for about 10 minutes, then tried again it started up no problem and was able to get to work.

Today, I was on the road for about 15 minutes at 50 mph, then it died again. It again cranks but will not startup. Tried to startup for couple of hours, giving breaks of 20 minutes or so between several attempts. I noticed the dashboard, all the meters max out (speed-o-meter, rpm meter, oil, temp, battery, everything) when key is turned. I also tried jumping from another car thinking may be the battery problem.

Called in tow truck, and after an hour my F150 finally arrived at the shop, and the mechanics were able turn it on on first try and subsequent tries afterwards. They kept it running for several minutes and no problem.

So we were talking about fuel injection problem. Then they decided to test drive it, and finally after 20 minutes it dies on them and cranks but won't startup. And of course, all meters/gages max out. They now believe it's the computer problem. But still not 100% sure.

My 2003 F150 SuperCrew is all original, and has 56,000 miles on it. Need advice... Thanks.

 

Computer problem? they always say that when they have no clue. Sounds like alternator to me.. Bad connection.

 

first you or they or whoever's gonna be working on it need to start with the basics, is it getting spark? fuel? we know its got compression because it still runs. if they have a scanner look at the crank position sensor when its not starting and see if it shows any readings while cranking. how olds the fuel filter? is the security light staying on?
and jethat may be right about a connection issue.

 

where in texas are you?

Id start by checking power and grounds for the PCM before condemning it.


Are there any warning lights that come on before it dies?
Does it die when coasting, or a certain speed, or RPM?

 

The give away here is he gets the cluster sweep on the gauges. Thats almost alway a connection. The first thing I'd do is check the connections on the back of the alternator. Thats where its likely I think. it turns over but wont start and he get the sweep. Loose wire on the alternator. I'd do a fuel pressure test just to be sure. I really doubt the computers bad.

 

Can defective alternator or connection to it cause the all the sensors on dash to max out? But then it startup again if I let it set for long time.

 

If I let it set for long time, then it starts up no problem and I can drive it. I'm guessing that's an indication there's a spark and fuel? I'll print out all the suggestions here and show them to the mechanic.

 

I'm at Killeen/Fort Hood.
As I'm driving, it just cuts off unexpected. Due to panic trying to pull out of the traffic, I failed to observe the lights. So far it happened during 40mph to 50mph, I wasn't really observing the speed or RPM.

 

I'll agree with yer mechanic, it sounds like the PCM is dying. When the electronics in it get hot, it quits and leaves no codes usually. Another symptom of a dying PCM is constantly chasing codes that you fix only to have them come back over and over. But I'd also suggest checking all other systems before replacing it. I'd also look at a NAPA PCM. They are cheaper than a Ford unit and will come to you already programmed for your truck.

 

Bad connection between alternator and battery or bad alternator. When your gauges do a full sweep that is an indicator of PCM reset caused by low voltage.

 

The mechanic wanted me to take my F150 to Ford service center for full diag. So on the way, coasting towards the stop light, it almost died again but suddenly the RPM shootup by itself and saved me from getting stuck in the middle of the road. One other strange thing I've noticed is that, the left turn signal blinks twice faster (about 2 per second) while the right one is still normal (about 1 per second), strange.....

Took it over there this morning, but they were over booked and had to setup appointment for following Monday. Meanwhile I took it to another place for more diag. We will see what they got to say tomorrow.

I've learned lot from all of your posts and helped me to talk little more intelligently with the mechanics. Thanks..

 

Bad bulb on left side. Check them all.

 

LOL, it's always good to know the talk, or at least sound like you do. The best way to get ripped off is to not know what's going on, or not know the lingo. Vehicles start solely on the battery. Once they run, it's all up to the alternator to keep it going. With your vehicle dying and not starting, there are two things it's not getting, spark and fuel. Both of those need at least 11.2 (or something like that) volts to operate. A lack of voltage can be caused by the alternator not charging. In your case, it doesn't sound like a battery issue since it does eventually start up again. It could very well be an ECU issue, which would suck because I heard those are not cheap to replace and reprogram. Either way, hopefully your truck gets fixed, and for good! Let us know the outcome!

And if the mechanic can't fix it, there are two things you can do. Kick the bumper REALLY HARD, or wrap the truck in duct tape. Works every time!

 

Yeah, First time I got that it took me a wile to figure it out but that is an indicator that tells you you have a tail or break light out.

And If they try to charge ya to much for a new pcm,
I have the one out of my truck with only about 25K miles on it.

Phil

 

Don't know about the duct tape, but I will certainly try kicking the bumper


While waiting for Monday's appointment at the dealership, I took it to Midas. After diag, the tech tells me it's the PATS, and it can only be fixed by the dealership.

So, engine cutting off while driving 50mph, then unable to start although it tries to. Sit & wait for at leat 20 minutes and it starts fine. When ignition is turned (not at crank), all gauges sweeps to top w/ service engine lighted. And the left turn signal light blinks twice faster than right. All these problems are caused by PATS?