I have a 2007 ford F-150 4.2L. When I bought the truck I changed the radio to an aftermarket one. No problems. Then about 8 months later I have a tire issue so I park the truck pulled the battery and drove my other truck for a couple weeks. Now I've reinstalled the battery and it only cranks check fuel system from tank to cylinders it's getting gas. Replaced plugs wires and coil and crank sensor. Still just cranks. It's not getting fire at all So I'm thinking that it sat with out a battery long enough for the power to completely drain and reset everything now it's looking for the signal from the stock radio which I do not have. Can I bypass this some how? Or Is it something else? And my check engine light flashes 8 times when I turn the key on and the security light in windshield flashes every 3 sec with the key off

 

Open hood and take a good look around for chewed wires, mice and rats are active right now.

To confirm its not a fuel issue use a little starting fluid directly into the throttle body while cranking.

Report back with results

 

No chewed wires and when i changed the spark plugs all 6 cylinderswere full of gas it's not getting spark all

 

Take a look at this old posting for info on the check engine light flashing 8 times.

https://www.f150forum.com/f38/2010-f...-times-132082/

 

from what I gather from that. The engine will still start and run or else they couldn't complete the required driving cycle. I did not see anything on what to do if the CEL blinks 8 times and the engine won't start. I been working on trucks a long time and it's not firing I'm 100% sure of that I replaced coil, wires, plugs and crank sensor none of that helped I it acting like the pats have been threw but nothing has happened to make them throw. I have the right key. It's manual windows, locks and there's no alarm system on it. Hell it don't even have cruise control.

 

Have you pulled the Diagnostic Trouble Codes (DTCs)
Wet spark plugs could possibly be caused by clogged exhaust, possibly a failed cat. I have had success testing for clogged cats by removing the upstream O2 sensor to create a flow path and trying to start.

 

About to test cats today will post results

 

Ok so just scanned the truck and the only codes thrown was fuel rail temp/pressure sensor and fuel rail temp/pressure high.

 

Shaggy88,

It’s been a few days since you last posted. Have you resolved this issue and if so, please post the solution? Feedback is important so that we all learn solution paths to these issues.

Thanks in advance
Jimboy