Engine swap

[explorer98]

I talk about the engine swap before. I'll cut to the chase. After the swap in my 98 explorer from a 4.0 to a 5.0 I had to get the keys reprogramed but when I did it wouldn't crank at the time because of a harness problem so the ford tech didn't know if it took. Well it cranks know and anti theft is good but it wont start and their is no gas. So I was wondering if I need to have it reprogramed know that it cranks.

 

[RangerSVT]

Did you research and verify both vehicles had the same pats system? If you have access to a 96-97 explorer 5.0 ECU, you can plug that in to verify that it will run...


SVT

 

[explorer98]

I used the pats, engine harness, trany harness, and pcm out of a 99 explorer 5.0

 

[RonD]

Programming is fine if it cranks.

The CKP(crank position) sensor "tells" the PCM the engine(crankshaft) is turning so it will "turn on fuel and spark", this is a 2 wire sensor located behind the crank pulley, if it was left disconnected then a crank but no start would be the result.

Can you hear the fuel pump coming on for 2 seconds when key is on?
If not check fuel pump fuse, pull it out and test it.
Next stop would be the inertia switch in the passenger foot well or kick panel.
Hook up a test light or volt meter to 1 of the wires and a good ground, then turn key to on(no cranking), there should be power to inertia switch for 2 seconds and you should hear the fuel pump.
If there is power at the inertia switch(test both wires for 12v) but you don't hear the fuel pump then you will need to check the connector for the fuel pump power, usually in the frame rail.
The fuel gauge wiring is in the same connector, does the fuel gauge work?

If there is no power at either wire on the inertia switch then pull out the fuel pump relay and reinstall, have someone turn the key to on while you have your finger on that relay, it should click(on) with key on then click(off) again after 2 seconds, repeat a few times to make sure it isn't sticking.
If no click then double check the PCM connector, the PCM grounds the fuel pump relay to turn on fuel pump, so make sure all the ground wires around the PCM are clean and tight, PCM has several ground wires that are not shared grounds internally.

 

[explorer98]

Ok I'll look at all those and see if something comes up. Thanks

 

[explorer98]

So I found that im getting gas to my fuel pressure regulator but that's as far as it will go. The fuel rail has nothing in it or no pressure, so I think it is a bad FPR but if anybody thinks different let me know.

 

[bobbywalter]

sounds like its jammed.


so i assume you put starting fluid to it and it runs good?

 

[explorer98]

Yeah, I put a few sparys to see if it would do anything and it tried starting. I didn't want to use to much its a new engine and it hasn't been fired up yet.

 

[RonD]

So I found that im getting gas to my fuel pressure regulator but that's as far as it will go. The fuel rail has nothing in it or no pressure, so I think it is a bad FPR but if anybody thinks different let me know.

Can you hear the fuel pump when key is first turned on?
They are not quiet.

'98 should still have an FPR, '99 is when Explorer switched to returnless fuel system.

FPR has a vacuum line attached, check if it has fuel inside it, if no fuel inside suck on the line(attached to FPR) and see if it holds a vacuum, if fuel pump is working there should be fuel pressure at the FPR so sucking on the line should allow fuel into the rail, if you have the schrader valve pressed open it should spit out some air and then fuel.
If there is fuel in the vacuum line replace FPR, diaphragm is leaking, or if it won't hold a vacuum replace FPR.

FPR is held closed by a spring when engine is off to hold pressure in the rail, when started the vacuum in the manifold holds the FPR open at idle(highest vacuum), returning unneeded fuel to tank, then closes as RPM goes up(vacuum goes down) and more fuel is needed.

 

[explorer98]

yeah theirs pressure to fpr but nothing in the fuel rail. I popped the fpr of and it sprayed fuel out so with it off I turned the key over and fuel spayed out so the fuel pump is working.

 

[feellnfroggy]

disconnect the fuel rail from the FPR and maybe spray it out with an air hose (tire attachement to schrader valve? make sure theres no garbage clogging it from the swap? or just replace the regulator.

 

[RangerSVT]

Swapping the supply and return lines does wonders. As far as the rough idle, how did you set the cps?

SVT