2004 Explorer turns over but won't run

[Blazen8899]

Okay, so I'm at a total loss, hopefully somebody can shed some light on this situation.... So I bought this explorer non running from a private individual, they replaced the engine out of another 2004 explorer 4.0 and they could never get it running, their mechanic said the timing jumped a tooth which it did, I had my dad check it and the engine was low on compression (bent or burnt valves) and sure enough was out of time, we tried and tried to get this engine running but it just kept jumping time, so instead of replacing all of the timing components in that engine which we also didn't know the mileage on, we went and got the original engine from the people I bought it from that busted a timing chain tensioner... we replaced all the tensioners, guides, spark plugs, coil pack, and crank sensor... when my dad put the engine in it cranked over, ran rough for about 2 seconds and shut off, back to cranking but not starting.... fuel pressure is good, spark is good, and it's getting air... it also will not start on starting fluid, PATS system light comes on and goes off after 3 seconds like it's supposed to.... however when I was cranking on it the other day the small ground wire going from the negative battery terminal to the front of the car (above the headlight?) Started smoking and got really hot to the touch, hot enough I could only touch it for a fraction of a second... but it only did this after extensive cranking 1+ minutes.... any ideas are greatly appreciated, like I've said, I'm at a loss. It's a 2004 Ford explorer xlt 4.0 flex fuel

 

[LONO100]

Any time you continuously crank on a motor that wont start up properly those battery cables and terminals are going to get smoking hot. You don't want to crank it like that or you could damage parts and drain your battery.

When I tore down the motor in my old rodeo and built it back up years ago, I thought I had everything put back perfectly, then I cranked it and the motor looked like it wanted to hop out of the engine bay. After racking brain and thinking it was something major, I realized I had two spark plug wires crossed and it was firing out of order. Another time I couldn't get one of my cars to turn over after I had done some engine work to it, and it turned out I forgot to plug in the maf sensor.

Moral of the story is, the answer to the problem is often times something very simple and not some grand error. If you confirmed that you are getting proper spark, fuel pressure, air and compression, start looking at things like spark plug wiring order, relays and fuses, a properly charged battery, and check to see of all of your sensors are plugged in and working properly. Next check for any cracked hoses causing vacuum leaks. Once the simpler stuff is also confirmed good, then start working your way back in your install process. Good luck and update us on what happens.

 

[Blazen8899]

Well I've got it wired as
Engine Coil
3---6 1-2-3
2---5 5-6-4
1---4
Front of engine
V

I think that is the correct way.... all fuses and relays are working, sensors are all plugged in and tight.... the thing that is boggling me is that I can take out all plugs on the driver's side bank (4-5-6) and it starts and runs no problem, put those plugs and wires back in and no luck, just cranks... if my injectors weren't spraying could that cause it to not start with those plugs in? The only problem it's having is 4-5-6 not firing

 

[koda2000]

Here's a link with a diagram to how the coil/plug wires should go... The year/vehicle doesn't matter all the SOHC'S are the same.

http://www.autospost.com/cat/firing-order-1998-ford-explorer-4-0l-sohc.html

 

[LONO100]

If you have a multi-meter, check the resistance of the spark plug wires. If you aren't sure how to do this, there are plenty of videos on YouTube that will explain it.

Also, make sure your ecu/wiring is all squared away and good too. I'm literally spitballing b/c I can't physically see what the motor is doing, but lets make sure to cross all our T's & dot all of the I's before you dig deeper and start pulling things apart.

 

[koda2000]

It kinda sounds like one of the cams isn't timed right. When the plugs are pulled on bank 2, the bank 2 cylinders don't fight the bank 1 cylinders and the engine at least tries to run. What happens if you pull the passenger side plugs and leave the driver's side plugs connected? I guessing the driver's side cam is not timed correctly.

 

[Blazen8899]

Both sides run, just not simultaneously, pull plugs 4-5-6 and it runs on 1-2-3, likewise for the other side

 

[koda2000]

Weird. All I can think of is that the cams are out of sync. Probably by just one tooth, as any more than that you probably be whacking valves.

 

[LONO100]

im with KODA on this one. cam may be out of wack. i cant think of another way only half of your cylinders are firing at a time if it isnt a spark problem. have you looked over your cam?

 

[Blazen8899]

I haven't yet, but get this, the other engine that we took out because we thought it jumped time is still DEAD on time, I am almost 100% certain this one is still in time also

 

[Blazen8899]

Yes, as I expected, we are 100% in time, both cams are dead level with the heads on TDC.... so no time traveling explorer lol

 

[koda2000]

I have no idea if this is possible, but can the slots be level but a cam be out 180 degrees?

 

[Blazen8899]

They would both have to be that way.... and since it runs on both banks, just not at the same time, highly doubt that one

 

[koda2000]

Yeah, I'm just trying to get my head around this issue. For the sake of argument, let's say that one cam is 180 degrees out. The crank and pistons don't care where the cam is as long as fuel, air and spark happen at the top of the compression stroke and the valves are closed (not sure when the wasted spark occurs. Is it during the exhaust stroke?) If one bank is at the top of the compression stroke while the other bank is at the top of the exhaust stroke would it have the effect of having the plug leads on wrong on one bank and prevent the engine from running with all the spark plugs in?

Just spit-balling... It just seems like the OP is dealing with two separate 3 cylinder engines that are out of sync and fighting each other.

 

[Blazen8899]

Actually, I found out what it was today by sheer accident and other topics.... both my cats are stopped up... it would start, run for a sec then stall out and refuse to start... took my upstream o2 sensors out and she fired right up and blew out a crap ton of the cat.... soooo yeah, that was the issue the whole time

 

[LONO100]

wow, i am glad you found out the problem and posted back. this one was a straight up head scratcher. hopefully this thread helps others in the future. check those cats! i am suprised your CEL didnt go off.

 

[Blazen8899]

The only CEL I had was a forced idle code, and some shift solenoid codes... it even confused my dad who has been in mechanics for 30+ years lol. But yes, I hope this helps somebody else who might have the same problem!

 

[koda2000]

Humpf, I never would have guessed that problem was a clogged cat. So what do you think was the issue with the first engine (if anything)? The cat being clogged?

 

[Blazen8899]

The first engine my dad took home and cracked it open, well everything was right as it should have been. So yes, I believe that the other engine would have worked, had we figured out the cats were stopped up. But that other engine we knew nothing about, the one in there now is the original engine with 141,000 miles. Either way I'm just happy it wasn't timing or the computer / security system.

 

[LONO100]

i believe in my first post on this thread, i said the issue would probably be something very simple, but i never thought it would be as simple as a cat! i am going to keep that in mind if i ever run into a problem like this in my own repairs.