alright, first off i couldnt of done this swap ALONE ... without all of your guys' input and advice. so kudos to you

basically it boils down to tonight! eeks

ive done the swap from my 302 to a 351w (88 f150 4x4 single cab). right now buttoning everything up, and about to fill er up with some fluids... oil, tranny, ps, coolant... now heres the kicker..,,

i put the 5.8 ecu in, and kept the 5.0 harness in it. i need to know if theres ANYTHING i need to do before i try cranking her over... and PRAYING this thing works. cause i have only 1 day left before my trip.. cuttin it close.

ie: turn truck on (not crank) and let the computer read for a min or two ... you get the idea, anything i should do before the initial crank

let me know ..

oh btw.. .the only thing that didnt connect is a connection that comes off the TB air tubes (small ones on the side) , they go splice in to one tube with a "sensor" i think , and then go in to the charcoal can ... the 5.0 doesnt have that option on the harness so is it a necessity to hook this up "somewhere"?

thanks guys

 

alright.. so i finished everything and went to start it... right off the bat it fired up ......

BUUUUUT.....

quickly died there after, as in 2 seconds or so


so i tried again.. crank crank crank .. no fire

let it sit and yadda yadda...

tried again, same thing !!! fired up, died, then just crank


so im letting it sit for a bit to try again .. but any suggestions ... i know, air + fuel = running, but im just not thinkin its the fuel for some reason, the lines are hooked up and i primed the fuel pump before cranking..

any help ?

 

Let the fuel pump prime multiple times (10 or so) that's been the culprit for me in the past.

Not sure about the disconnected sensor, do you have a picture for clarity?

 

If you didn't change the computer its not going to fire. The 351 and the 302 have different firing orders. Thats gonna be a good place to start.

 

its running .. yea ...

i had changed the comp to the 5.8 but it just wasnt working.. so then i took out the 5.0 comp harness and changed that with the 5.8 i yanked out the donor.. and it works.. must be something with the pins not matching up, but i dont have time to trouble shoot..

my gas, temp guage dont work ... any thoughts?

 

You have two temperature sensors, one feeds the computer and is critical to fuel management. Its located on the thermostat housing. The other one that feeds information to the dash is located on the front of the block, passenger side, next to the water pump. Make sure the wires are connected, and the sensor is good, they are pretty cheap to replace.

 

check the colors of the wires also. I just finished putting a 302 in what was a 300. I ended up taking most of the wiring harness. And that was the donor bronco was an 80 to mine an 85 just to make it work right. any thing newer and I would be sure it would be tougher.

 

yeah ive been driving my 351w just swapped from 302. Didnt even change computer. Its running like crap though. Thinking about swappin comps.

 

I swapped a 351w in place of a 302 in a 93 f150 and had no problems i used all the wiring from the 302 and the 302 computer runs great last time to the drag strip i ran a 15.1 quarter mile smoking the tires through first gear with a spooled rear on a completely stock fuel system. I dont think it matters what computer you run unless it is a mass air truck. Speed density trucks are bank fired injection not sequential.

 

the firing order doesn't matter on that swap because any fuel injected 302 that you find is going to have the same firing order as a 351W it's the earler pre-80 302's that had a different firing order.

don't have the slightest of a clue about the rest of the stuff though

 

Wanna bet? The speed density 5.0s in trucks use the 15426378 firing order.

 

I had been looking to change my 1996 302 to a 351. All of the info I have looked at says that only the 1994 to 1996 302's and 351's have the same firing order. Now I really confused.

 

there different, but you can change the firing order at the distributor cap.So either computor will work.

* ASK ME HOW I KNOW *

 

All you need to do is change the firing order to 351W. The speed density computer doesn't care. I put a used 302 in a 90 Bronco (original engine was 302 as well) and it would not start. I tried everything, it had fire, fuel, compression, etc. Spit, sputtered, would not start. I started to wonder why I got the engine so cheap. I fooled around for several days, no start. I wake up about 3am and think "some nitwit put a 351W cam in that 302" The next morning I went out and changed the firing order to 351W and it started right up and ran fine.

 

which flywheel do you use when you swap out a 302 in a 90f150 w/aod with a 1988 351w that had a c6?