Does anyone know if its a good idea to swap 4.9 l i6 for a 281 (4.6) from a p71 crown vic into a 1988 f150??

 

Doable if you are wealthy enough and stubborn enough, but IMHO, bad idea.

 

it is not a good idea if you're looking for a quick, cheap, and easy project.

 

what would be. A quick, cheap, and easy project? The truck has been sitting for 10years + and it won’t start. I assume its the ECU and i bet theres a whole bunch of wiring issues. But there is spark, and fuel delivery.

 

Don't assume anything!

If you have spark and fuel delivery, it would seem more likely that that your ECU and wiring are just fine.

 

If there is spark and fuel and won’t start are you in a vacuum ie no air? Check for codes and start doing some diagnostic work. How old is the fuel? If you are trying to burn the 10 year old “fuel” that could be a problem.

 

My thoughts too. ECUs just don't go bad that often but 10 year old gas wouldn't burn if you threw a match on it.

 

4.6 in anything

Pull codes before you rid yourself of the i6 just to get it running....if you want more power, the 4.6 isn't the answer.

 

 

will do!👍🏼

 

So you are trying to draw the fuel from a gas can using the frame mounted pump?

 

yes sir i am

 

So, the fact it runs when you spray gas in the intake says you do not have fuel delivery. Check to make sure your fuel pump is running and check fuel rail pressure with a gauge.

Running off an external tank with the frame mounted high pressure fuel pump is possible, but the factory tanks also contain pumps that deliver fuel to the HP pump. It's not a great lift pump, so set your portable tank higher and set up a siphon feed or use a low pressure electric pump between the tank and the HP pump. Also don't forget your return line which is delivering excess fuel back to your leaky original tanks.