My truck has been having issues with starting consistently over the past week. For a little background the place I work has two facilities that I have to travel between daily. The typical sequence of events is below:
1. Start up in morning and drive to facility 1 (approx. 7 miles) without any issues.
2. 30 minutes after arriving at work I have to travel to facility 2 (approx. 2 miles). Truck starts without issue.
3. Roughly 2 hours after arriving at facility 2 I have to return to facility 1 (again 2 miles). Truck starts without issue.
4. Usually 2 hours after arriving at facility 1 I head out to lunch and the truck will not start.

The same issues repeats in the afternoon. This has happened everyday this week. Each time the truck will not start i have tried to start it with a jump box without any success. I have to get a jump start from another vehicle to get it going. After starting I do not have any issues with it staying running.

Yesterday I had the battery tested and ended up replacing the battery. Today I had the same issue as outlined above, got the truck jump started and drove to AutoZone and had the alternator tested. The alternator tests good.

So far I have eliminated the battery, alternator, spark plugs/wires, and starter.

What else could be causing the nonstart issue? The first time I try to start the engine tries to turn over but acts as if it is not getting a spark.

 

Eliminated alternator, battery, engine grounds, battery cables, battery connectors, coil pack, O2 sensors, crank shaft sensor, cam shaft position sensor, water temperature sensor, fuel pump, fuel pressure, fuel filter, MAF sensor, PCV valve, IAC, TPS, and compression issues.

What else would prevent a vehicle from starting?

I do not think it could be the PATS becasue the starter does turn the engine just will not start up.

 

You said you checked the fuel pressure. Was this when the truck was running or when it didn't start?
2 things I would still check are the connections to the inertia switch as they may be loose or corroded.
And swap out the fuel pump relay under the hood with , i believe, the AC relay.
PATS will still let the engine turn over without starting,or from what I have read, the engine will start one time and run for about 20 seconds then stop and won't restart.

 

^if you try and use a non-coded key to start a PATS truck the engine will crank but it wont start

 

Thanks for the responses. The fuel pressure check was done when the truck would not start. When I turn the key I can hear the fuel pump running.

The one thing that keeps throwing everything off though is that the truck will start with a jump from another vehicle. That makes me think that it is in the starting/charging area. Also, interstingly enough the issue did not come up today and I am not certain if this was because it was warm outside all day or if I accidently solved the issue while plundering around under the hood this weekend looking for broken connections and bad parts.

Is going to the dealer the only way to confirm if the PATS is working properly? i.e. the key has not "lost" the program. I only have one key, so programming a new key or checking with a different key is not possible.

 

Get the codes read from the PCM.Since the problem is intermittent a code may be stored that won't trigger the CEL.

 

I will check the codes as soon as I can.

It was my understanding that after the PAT system stopped the vehicle from starting that the truck would be immobilized until the system was reset by the dealership. Is that incorrect?

 

Same problem here once in a blue moon. I researched and found the solution. The fuse box under the hood on driver side, has an small relay I call them "ice cube relays." Any who that relay is k4 it has something to do with the fuel injection. It gets stuck sometimes, simply knock on the fuse box a few times and I bet it starts right up. This will get you by for a while. But, the ice cube relay needs to be replaced.

The voltage from another vehicle may be enough to pull that relay in. Just a thought, but idk.

It fixed mine.

 

This may help locate it. Left hand side, 4th from bottom. Fuel Pump relay. Cheap part.

If not check the inertia switch behind the passenger side kick panel, they are know to have intermitten failures.

 

I will give that a try. No codes were found when I checked for them.

I did try cycling the key on-off-on-off 5 to 10 times and it started right up. So now it is down to PATS or the fuel relay.

Thanks for the help.

 

I was having the same problem, the fuel filter was clogged, I know you had a recent fuel pressure check, but you never know....filters are cheap and easy to change....worth a try.

 

The issue is a bad fuel pump relay. When I had the no start issue I swapped the fuel pump relay with another in the fuse box and the issue went away.

 

good to know. I get an odd intermittent long crank, usually after the truck sits for an hour or so after driving, like I'm at lunch or at the store. Long crank/no start, cycle the key and it fires right up.