Explorere ECU and harness swapping

[JoshT]

It seems that an engine swap is creeping closer to necessity for my 99 Ranger. I'm on the look out for an intact, low cost, V8 Explorer donor but haven;t found one that meets the right criteria yet. Namely 1999-2001, AWD, and preferibly <$1000. I don't know if the Ranger is going to wait for me to find one that checks those boxes.

I actually have a 2WD V8 drivetrain from a rolled 98 Explorer, that was running good when I purchased it for another swap almost 13 years ago. I would need/want to go through it before installing it, really want to build what ever engine I use before installing anyway, but that's fodder for another thread. I'd also convert to returnless to match the truck, already have fuel rails but need to get injectors. Point is, I should have everything I need for the EFI on this engine, except that the wiring harness was butchered to make it run stand alone for use in the other project.

I spotted a complete 2000 Explorer 5.0 harness on Facebook marketplace the other day. Could I use that 2000 harness with my 1998 Explorer 5.0L ECU and electronics, or would I need to find a matching 2000 ECU and some various sensors?

As of right now I'm planning to grab the harness. IIRC they were asking $100 and it's worth that if in good shape. I just don't know if I'd need to find a matching ECU and/or other electronic components.

FWIW I actually have 2'98 ECUs, one is stock and the other has had PATS disabled and shift points tweaked slightly. Although I don't have the Explorer's PATS equipment, I should have access to everything necessary to fix a potential PATS issue.

 

[scotts90ranger]

The V8 Explorers went to returnless fuel supply in '98 (along with the higher fuel pressure) so the '98-01 should be interchangeable, I have a '98 and a '00 V8 Explorer and both look identical under the hood other than random redneckery that happens over the years. The only thing I don't know about and I know there are a couple differences is the cam sensor deal but I'm pretty sure it's the same starting in '98.

 

[JoshT]

Explorers went to returnless in '99. The '98 Explorer I got back in the day was a return system, but it can be converted to returnless just by swapping the rail an injectors to the returnless parts. Maybe some 98s were returnless, but most hould have been return from my understanding.

I know the fuel system end if what I need. Picked up a returnless rail a while back knowing that using this 98 engine in the 99 would be a possibility, just need to get the matching injectors. The harness I spotted says that it includes the injectors, but who knows the condition and I will probably need/want to upgrade to support power goals.

Cam sensor, I'll look into that. If it's the same, great. If not, it might be an issue. I should have the 98 cam synchronizer & sensor, but if a 2000 harness doesn't have the same wiring it won't work.

I'm not really concerned with the fuel system side of the equation, I've pretty well figured out what I need there. Just not sure about the electrical.

 

[scotts90ranger]

I think the sensor is the same it's just the synchronizer or whatever that pugs into the block that's different, the sensor is even the same as a 3L or 4L Ranger... There were a couple different styles, if it helps here's what was in my '00 I rebuilt recently to compare with what you have (yes, that's all I did when lining it up for reassembly, just lining up the sharpie line, pic is on disassembly which is why it's gross). I think if you change injectors and check the cam sensor you should be good to go with your plan.

Now that you mention it I do remember hearing it was changed at or after '98, I've honestly not looked at the fuel lines on the '98, one of these days I need to pull the upper intake to put in new valve stem seals and valve covers along with the cast manifolds from my '00...

 

[JoshT]

There were a couple different styles, if it helps here's what was in my '00 I rebuilt recently to compare with what you have (yes, that's all I did when lining it up for reassembly, just lining up the sharpie line, pic is on disassembly which is why it's gross).

Used engines are dirty, and if the Sharpie mark works there's nothing wrong with it. Assuming that you didn't touch the crank ( or it was lined up on TDC #1 before and after) the Sharpie mark should work just fine. The tool is mostly needed for new installation where the originan alignment isn't known.

That said, I'll probably have the tool when doing my rebuild (if I don't already have it).

 

[scotts90ranger]

Just noting things, I do sketchy stuff but have my limits . That guy is a small diameter, I'd prefer larger since it increases accuracy but I'm sure it's close enough... yes, that mark is at TDC, the tool likely lines up the right side of the vane to the center of the window. Plus or minus a couple degrees shouldn't be the end of the world, I wasn't building a race engine living on the edge... I never know who is on the other end online, some people are bright and others are the dullest spoon in the drawer, I root for everyone so try my best to help out . I learned a lot of things from here over the years, I was VERY green when I got here...

 

[lil_Blue_Ford]

So, I did a 98 Explorer drivetrain that I converted to 00. IIRC, the difference was the fuel rail and injectors and the cam sensor went from 3-wire to 2-wire and the part that went into the block was different. Of course the ECU too. Easy enough to change over other than I broke bolts at random points in my attempts to freshen up the motor some. I bought a set to align the cam sensors, the part number for the alignment tool that’s listed in the tech archives is for the 98 and not the 99-01. The set has both, I’ll have to look up what I got.

FYI, my timing chain had a stupid amount of slack and the cam sensor was actually broken, at 160k. Not the lower part, just the sensor. Darn thing actually ran pretty decent and I have no idea how. All that is fixed now.