Hello guys. I have an issue for two weeks now and I would appreciate your help. I have 2000 f150 with v6 engine 4.2 liter. My problem is that the truck wont start up. It crunks once and just make some kind a noice like something is spinning inside engine. I put a new battery and same thing happen again. I went to the autozone with my starter they tested and it was ok. Anyway I got new starter and replace it. Same thing again. Fuel pump cliks which means it is working. Cranks once and it wont turn on. So than I changed: starter selenoid, spark plugls, coils, oil and oil filter, fuel filter,air filter and air intake valve sensor but the problem is same. I finally got it running after 20 times of trying to sturt up. Idles fine. Test drove it. It drives fine. Kept it running for an hour and works perfectly but once I shut it off same problem again. Cranks once and thas it. So I just figured out that if I turn the key on and wait for at least 20 seconds or more it would start up. Not always but most of the time. So is there something that you guys thing I should check or change since I am not mechanic and I really need to fix this because I need a truck for my work. I would appreciate any help. Thank you

 

First, check grounds and battery cables and connection.
"Cranks once " starter turns engine, then does not turn engine? Or. ... starts running for a second, then dies. Turns over but does not run?
I hear people confusing starting and cranking all the time at work. ......

 

Thx for your reply. It does crunks but engine doesn't strats. Checked all cables and fuses. Every ground that I found I cleaned it.still same problem. I Just ordered fuel presure regulator. Could that be an issue?

 

Ok. Check fuel pressure. Check for codes.
Check the theft system.

 

With the Key on have you tried to jump the starter solenoid? Do you have an aftermarket security system? these may cause some issues too.

 

Ok guys here is a thing. First of all thank you so much for your opinions. As I mentioned before here is what I changed so far (battery, starter, starter selenoid, ignition coils, cables, spark plugs, oil and oil filter, fuel filter and fuel presure regulator, cranksaft and camshaft sensors, cleaned mass air flow sensor). I checked engine presure, spark plugs and everything is fine. Today I checked fuel presure. Runs around 35 key on engine off and ariund 40 engine on. Still no start up. I have ti try for like 20 times to start up engine. Today I figured out that when I turn key on wait two seconds and turn off than again on and off for like three or four times than the engine start up right away. So three times key on and off and it fires right way. Could that be a fuel pump. That is the only thing I did not change. And I forgat to mention I drove it today on a highway and it runs as new, way better than before. This is a work truck so theft system is original and it blinks for two or three seconds than goes away. Thank you so much for your support

 

No codes att all. Theft system blink twice than goes away.

 

Same thing happens crank it with the key or with the jumper on starter selenoid. Cranks once than make noise. After twentieth attempts engine turn on.