has any one ever had an issue starting the truck. Starts, runs great, shut it off and then it will not start. Let it set for a spell and bam! starts and runs like a champ! Perhaps a CRANK/CAM sensor issue. Please help.
you can email me at rpny@aol.com or rpny@comcast.net (perferred email)
Thanks

 

Post in the engines forum as well - No email needed

Sounds like a PATS problem.

BTW - Fill your info in and you'll get more replies. Truck, year, motor and what you have tried to do to resolve.

 

Thanks jbrew,
what is a PATS problem?
I have a 1998 F150 4.6L V8 Triton 4x4, and I an new to this site so please bare with me, I am not sure if I am doing this right or not. Any info is much appreciated.

 

Never-mind, you don't have them.

Air filter, fuel filter changed recently ? MAF sensor been cleaned ? If so, the regulator could be over pressurizing the rail. Pressure bleeds off after awhile, then she starts.

Run fuel pressure tests. Test the pump.

Could also be the fuel pump relay. It's next to the horn relay. Feel it while she's running - If hot, it's bad. Questionable? Swap that relay with the horn relay = Same thing.

Do you have a CEL illuminated ?

Well, that gives yuh a few things to check out anyway.

 

I had similiar symptoms w/ a failing fuel pump. Listen for the whine of the pump when you turn the key. Do you hear it when the truck will start, but don't hear it when it won't start?

 

Guys
Thanks for your input, I will look into all of this. Not sure what a MAF sensor is but I have goggle so I will find out. I can never hear the fuel pump, starting or not starting, just can not hear it while I am in the truck. If you hear of any one else with these issues or any other answers please pass me the Info. Again thank you for your help I will look into it.

 

Hey jbrew
I've got the same starting problem. I've noticed when the cel is not on it won't start. When it is on it will start. What causes the cel not to come on everytime I turn on the key? What makes the light come on?
Gary

 

Not sure what exactly "On" refers to for you Gary ?? Run? Start? Works like this, with the key in the run position -and engine not running = (KOEO),- all models, - CEL should be illuminated. That's how you check the bulb - Think it's also connected to the cig lighter/pwr port fuse ? Maybe not, that might be the DATA port below I'm thinking of. Anyway, that's about the extent or relation to the CEL from Ignition off/start/and engine running.


{Key just in the run position, without engine running = CEL on.}

 

Hey jbrew
On is when I turn the key to the on position. Not the start position. When the CEL does not light it won't start. When the CEL light comes on it does start. When I get ready to start my truck I check to see if the CEL is lite up if it is I go ahead and start the truck. If it's not on I turn my key back to off and cycle the ket until it does light then it will start. On means all the lights come on on the instrument panel, not the start position. So What it does is sometimes it will light when the key is turned to on and sometime it dosen't come on until I cycle the key a few times.
Thanks Gary

 

Right , but turn the key to on and don't start it . Is the CEL on or off. Doesn't matter @ start, it should always be illuminate in the "on" or "run" - Same ignition position. Don't turn to start, just on to check the CEL.

No Cell in on position? There's a short somewhere. I can give yuh more info, bu want to make sure your pausing @ on first and that this is what your referring to..??? I'm not sure , I think you are lol, just not 100%.

 

Hey jbrew
When it's in the on position not in the start position. This when the CEL light, lights up sometime and then sometime it doesn't. I pause at the on position to see if the CEL is on. When it lights up I can go ahead and start the truck. When the light is not on I don't even try to start it because it won't start. I need to find out where the power for the CEL is and check for a short. This can happen when it's hot or cold. It always starts in the morning. It seems to be worse if I've been driving for while, if I get out of the truck for 5 to 10 minutes and then try to restart it right away it won't start some of the time . If I cycle the key for a few minutes it will eventually come on for me and start.
Thanks Gary

 

Yea, that explains it, finally lol. Right, you should have a CEL every time in Run/On positions with engine off.

Sounds like a relay problem. Turn key to run w/hood open and put your hand on the relays. Find the hot one (by touch) and replace. Check relays under the dash as well.

 

Great clue Gary, thanks

I just swapped all similar relays and positions, both under the dash and under the hood. Lets see if this works. If it does, I will replace all relays with new

 

What are you thanking him for

 

He noticed something that I did not (about the CEL Light relating to the starting issue). I am thanking him for his observation.

So far my truck runs and starts since I did the Swap. Not saying this is the cure for the problem, time will tell. If not, maybe I will replace fuel pump.