has any one ever had an issue starting the truck. Starts first thing in the morning, runs great, shut it off for a short time and then it will not start. Let it set for a spell and bam! starts and runs like a champ! This does not happen all the time but you never know when ity is going to happen, it is a guessing game. Perhaps a CRANK/CAM sensor issue. I have done some reading on this on the internet, a lot of the findings point to Crank/Cam sensor but I am not a mechanic so I do not know for sure. I posted this in another section and was suggested to post in this engine thead as well(thanks jbrew). It does not just stall when running nor do I get a check engine light, does any one have any ideas as to what the heck this is? I have a 1998 F150 4.6L V8 Triton 4x4 ext cab and this is the only issue that I am having, I love her and dont want to put her down, please help.
Thanks

 

sounds like somethings overheating to me.
does it happen often? check fuel pressure next time it happens if you can. maybe rent a fuel pressure gauge from autozone if they allow it, and when it happens check the pressure. if its not fuel then check for spark.

 

Do fuel injected engines get "vapor lock" or is that just a carborator thing? I am about to just pull the engine and put a new one in... So confused, any help is apperciated. Thanks

 

yes they can get vapor lock

 

I know they will not start with new injectors unless you hit the shrader one time.

Also, if you crank the motor more than 5 seconds and -No start. It's not going to. The PCM shuts down the injectors to protect your cats.

Either come back later (needs to reset) - or pull the PCM fuse (disconnect battery). In other words - "Re-boot".

She won't start if the regulator is acting up aswell. To much pressure at the rail will cause a No start.

I thought I told you all this in the other forum and thread you have goin ?

https://www.f150online.com/forums/19...ing-issue.html

Right ! I did. Sounds like your regulator to me.

Actually under troubleshooting , problem with warm starts it lists one thing - Regulator. So aparaently, your not taking the info seriouse? Or not telling use what or how you tested. What gives? Did the regulator pass? What were the number variations -vac on/vac off? Do you honestly want help lol?

 

I have been chasing this one down also, same exact symtoms

I verfied that the pump is not working when it don't start. You spray starting fluid in the air intake and it runs for a while.

Checked fuses, relay, and connections, all good.

I think its time for fuel pump replacement. What baffles me is when I wait it will start up. You figure when the pump dies, it's down for good.

I did not try to reset the PCM, will try that before the pump replacement