My bf and I have been working on the truck we bought a couple months ago. It’s a 2006 Ford F-150 5.4 triton lariat. We did an engine swap and now that everything is back in place it won’t start. We checked to make sure sensors and connectors were plugged into the right places. The engine turns over and has fired a few times but won’t stay running. We thought maybe it was the anti theft but it wasn’t. It went into fail safe mode and we got that figured out. It’s got all the fluids it needs. We replaced the oil filter and fuel filter. We just can’t figured out what else could be causing it to not run. Our next step is to check the timing chain. Any suggestions on what it could be or what to look for?

 

codes? spark? fuel pressure?

 

Sounds like you both did a lot of work.

Just a question, when you bought the replacement engine, was it tested and working? Any warranties/guarantees?

A few months ago a friend did the same thing with their vehicle (not a F150), but got a bad engine. They asked me to look at it, and before I did anything, I asked if they had any recourse before me looking at it. They contacted the place they bought it from (reputable local scrap yard), and they offered to swap it with another one as long as no-one opened it/fiddled with it.

I know it's a long shot and more work to swap it, but personally, I'd rather get a known working engine and be done with it, than trying to play cat and mouse with replacing parts.

 

It was a used engine that we bought. It hasn’t been throwing any codes. The check engine light is on though. We’ve checked the spark plugs and coils multiple times and they’re fine. Checked the fuse box and that’s all good.

 

If the check engine light is on there should be codes.

 

Okay we no longer have the check engine light. We have no codes. It will start and run but then it will kick out. Everything appears to be fine it just won’t stay running. Any suggestions?

 

Check the FPDM for corrosion.

 

FPDM was replaced so it isn’t corroded

 

Use a scanner that can read out the fuel pressure PID and see if it's losing pressure. I assume it dies no matter what you are doing with the accelerator pedal?

 

Even with the pedal to the floor it still dies. We will try read the fuel pressure.

 

When you did the engine change you may not have reseated the torque converter correctly, possibly damaging the front pump seal.