2003 4.0 won't start after engine replacement

[IndianaKenny]

A couple of days ago I swapped an engine in my 2003.

Everything went as expected, except the engine wont start.

I've got good compression everywhere, fuel pressure at the fuel rail, a noid light tells me the injectors are cycling, but the darn thing won't run.

I bought the truck knowing it had a broken timing chain, and expected it to run, after the engine was swapped. No luck.

Yes, I used the original injectors and fuel rail, camshaft, knock, and crankshaft sensors.

I spent today swapping other sensors around, to no avail. I also went through each and every vacuum line and rubber boot, to see if there was a crack or leak, again, to no avail.

The only odd thing I see is that my spark tester flickers ALOT more than I expected, on each cylinder. Again, crank and cam sensors swapped, but no difference. I'm gonna put another coil pack on, but this will be number 3, (Thankfully I have a box of old parts from the last swap).

Any suggestions?

Thanks!!!

The

 

[drdoom]

Do you have a strong odor of fuel from exhaust? Is that a recycled engine or a reman?

 

[IndianaKenny]

It's a recycled, and I haven't sniffed the exhaust.

 

[boominXplorer]

I had the same issue with a 2006 Explorer one time and all but 1 injector was stuck closed from sitting. It had been sitting for a year with an empty tank (luckly). I hit them all with a 9v battery and all but 1 came alive. I ended up swapping to a set of newer injectors to save a headache since I already had them on the shelf.

 

[IndianaKenny]

Interesting!!!

After your post, I have found some videos of guys who have cleaned their injectors with the 9vt battery. I'll try that in a day or two. I'm gonna take a day off from working on the Explorer, to hopefully get a list of suggestions, so when I take off the upper intake, I can check what I hope to be additional suggestions.

I've spent alot of time putting on and taking off things, and need a couple days of a break, from my frustrations.

 

[IndianaKenny]

Spent this morning removing intake and fuel injection system. Tested all injectors, with the 9vt battery, cleaner, and some pressure to the injector. All injectors cycled fine, and I had a real nice flow of fuel, from each injector, (all 4 injector holes spit out a nice stream).

I don't get it, is it possible the PATS system is acting up? I've got fuel pressure, I've got spark at each plug, I've got pulse to each injector.

The light blinks normally when the key is out. Insert the key, and it goes steady for a couple of seconds, then does not come on again. This, I think, is normal, please tell me if it's not.

Any ideas?

 

[Duranged84]

Possible bad mass air flow sensor? Try unplugging it and see if it'll do anything different. Swapped cam and crank sensors? Could also be intake bolt gaskets, if you've had intake off a time or two. The rubber gaskets on the bolts are crap and cause a lot of headaches on these and Fords 3.8/4.2L engines.

Lets start with unplugging the MAF, then if you've swapped cam and crank sensors.

Does it act like it wants to start or just crank steady like its not getting fuel?(I know you said fuel is fine, just trying to get an idea of what its doing)

On your PATS question, Im going to say probably not, I just had a dealing with one that the non-Ford programmed key went bad/dead and it just wouldnt do anything. All lights and stuff but no starter at all, no click, nothin. After checking wires and pulling starter to test/swap with one of my spares, It hit me that the key didnt feel right or have the emblem on it. Had them grab their spare key, which was a Ford original. Started right up.


Thinking about it again, If youre getting spark to each cylinder, you might be able to scratch cam and crank sensors off the list, but wouldnt hurt if you have spares. Really racking my brain here, Have done two 4.0L swaps in the last couple months, and maintain 4 of them.... One of them went from an explorer to a ranger, so fuel and intake systems were different, but all other sensors, etc were the same.(also it went into a year newer ranger, so year difference shouldnt matter as long as its a SOHC engine. All of Fords 4.0 SOHC engine long blocks will interchange with minor bolt on differences.

One other thing, but not sure if it would keep it from starting, did you double check the knock sensor wire/plug while you were in there?

 

[IndianaKenny]

I've swapped maf sensors, no change.

The rubber boots for the intake SEEM fine, my main concern were the oval gaskets that mate to the intake/block.

I've bowed my head and just had it towed to my buddy at the local Ford dealership. He's gonna check it out with his new fangled coputer. I will post the results, as soon as they come in.

THANKS to all of the enthusiasts who have been reading and commenting on this post. This group is fantastic!!! I really appreciate the struggles we have, and the fellowship of the Explorer Nation!!!

Talk to you later!

 

[Duranged84]

Keep us updated when you find out what it was, hope it's something simple and easy.

 

[IndianaKenny]

Got an update from the dealership....

It seems I have an "overfueling" problem.

They said the engine coolant sensor thinks it is only 10 degrees outside, so it has been dumping fuel into the intake, to get it to start. I understand, and was not expecting this $15.00 sensor to be giving me soo much grief!!!!

This is the only sensor I did not replace during the swap, because it was the same part number, so I didn't think it would matter. Leave it to me to buy a replacement engine, with a bad coolant sensor. I have two or three used ones laying around in the garage, but I'd have never expected the thing to be bad, and certainly would not have thought it would cause a "no-start" problem. It does make sense, how it would try to over-fuel in cold weather, but in my warm garage, where everything is nice and warm, I didn't see it coming!!!

Anyways, keep this in mind if you ever get an over-fueling issue, your coolant sensor could be the culprit!!!! Damn coolant sensors!!!!