I have a poorly running 351w in my F-150 now. I found a good running 5.0L I could get and put in but, would my 4-speed bolt up to it? NP435, and what all would I have to do being fuel injected? New wiring or just computer?
to swap to fuel injection you need lots of money, a donor truck, time, patience, wiring harness, sensors, intake (both upper and lower) fuel pump, lines, filter, rails, injectors, computer, the emissions parts alone are more complicated than your entire current engine. and with fuel injection 302 stuff doesn't always work with 351 stuff.
You'll need the correct 302 flywheel for whatever tranny, clutch, torque converter etc that your truck has. Also be aware that the balance value on SB Ford flywheels changes with crank, pistons,rods, and year model.....which means that not all 302 flywheels work proper on all 302 engines.
Ass'y brackets are different. Smog stuff is different. Headers interchange but y-pipes, connectors and head pipes don't. Sometimes, the starter will be different on account of the tooth-count of whatever flywheel you end up with. Distributors are different, as-is the intake systems.
That's just off the top of my head, there's probably a lot more than what I mentioned.
It aint that hard of a swap though. Main thing is, like the man said.....get everything with that 302 motor that you can get.
First, "pull fault codes" from the vehicle computer and see what indications there are as to why the engine is running so bad, no?
If you have a Haynes Repair Manual and/or an OBD-II code reader, perform TESTS ~ KOEO = key on engine off and KOER = key on engine running...
For how to, go here: www.fordfuelinjection.com which has FREE code numbers and explanations...additional help: www.broncolinks.com.... and in doing so you'll get a better idea diagnosing rather then just throwing money at a problem that might be more "cheaply" resolved...
Do a wet/dry compression test on the cylinders and see what you come up with...
Evaluate ALL ignition and sensor components, these are integarl for a vehicle's performance...
Search for any vacuum leaks......a common indication of poor performance..
I would also stay with the OEM 351, you could probably buy an inexpensive long block rebuilt kit from Federal Mogul or somebody for less then half the price of new long block....my new 302 EFI long block cost $1,575.00 with core exchange in Sept. 2008....
There's ton of information available on this site at your finger tips to help you sort this out, this is all first hand experience from all of us here who've had similar problems like yours..
So before you do anything, invest some FREE time searching and you'll come up with the right direction and action to take....
Yeah, the PO decided it was a good idea to take out the auto transmission and 8.8 and swap for the np435 and 9in and insert 3.50 gears from the 3.73's it had
and its hard to do KOEO or KOER without the gauge cluster the PO also removed and threw away (nothing there currently, trying to buy one) , but the tests or finding a code puller or paying $30 to pull codes was happening eventually.
I've found a couple vacuum leaks and plugged them. Sounded like it was missing when I first got it, put some new plugs in, cleaned the IAC, checked the TP Sensor.
Jopes, what could be some of the running issues from the tranny swap?
Thanks again, anymore help would be wonderful, have a few other places to start now.