Ok so I purchased a 97 F150 with a 4.2 V-6 from a friend who claims it ran about a month ago. No reason to doubt him. No battery so I could not start it. I got it home put a battery in it but it would not start. I can smell fuel and checked for spark all good. While cranking it stumbles and tries to start. After a few attempts it ran terrible for about 30 seconds. Tried again and after a few more attempts it sent a flame out of the throttle body 2 foot long. Very cool glad I was"nt in front of it. I put an obd2 on it and I get no codes at all. Have no clue what it could be because I have no codes to go by. Any help would be greatly appreciated. Thanks, Pat

 

Any ideas at all. Really could use the help.

 

Had a friend who does mechanic work look at it and he claims its blown up ????

 

Sounds like it's jumped time. Start doubting your friend.

 

Yes thats pretty much what I thought. Why would a blown motor try to start and run for at least 30 seconds.

 

It'll start and run if it's jumped time till the piston breaks the intake valve or the valve holes the piston.

 

Check the key in the crank pulley. If it is sheared or badly worn it will act like it's jumped timing.

 

Ok so I checked timing chain and gears all good. I have spark and fuel. Put new motorcraft plugs in it. It tries to start but all it will do is backfire occasionally. Even tried to put starter fluid in it but it only backfires. Replaced sensor on the crank (got one for free). I put it on a Snap on scanner and get no codes whatsoever. I am at a total loss. Am I missing something, maybe something that could fail but not throw a code.

 

I am thinking I may have put the cam position sync in wrong but this still does not explain why I do not get any codes. Any ideas ?????? Thanks

 

You won't get codes if the engine won't start.

 

Good point glc. I had a hunch that the cps was in wrong and it proved to be right. The truck starts but no oil pressure at all. Looked inside the cover to see if it was splashing around but its not. When I pulled the timing cover I had to replace the oil. Now this comes up. Checked the oil due to the previous owners lack of maintinence (sludge) and found the new oil to be crystal clear. I would think it would be a bit dirty if it were circulating. What would stop the flow of oil besides a clogged pickup screen. Thanks all.

 

Probably could be a bad oil pump. Is there any way to test it. I pulled the pressure sensor and cranked the engine to see if oil came out but it did not. I am not sure if this would be a valid test but came up with it on the fly. Anyone ????