98 to 99 motor swap. Will start then stall out

[Peoplesperson09]

So I got a 98 Explorer overhead valve I swapped into a 99 Explorer overhead valve I changed over the wiring harness the sensors the PCM had the key reprogram this morning the vehicle will start and idle then stall outwill stall out.. I'm getting codes 0102-0135-0155.. motor was completely rebuilt before reinstall.. 98 motor was running and driving before rebuild. Bad headgasket

 

[Turdle]

Check mini fuse 13 in the power distribution box under hood.

Check the square connector near firewall, make sure it's tight.

2nd gen issues? Try this first!

Sometimes a gremlin can be caused by the smallest thing. There are 2 large wire bundle connectors on the firewall. Both are held tight with a 10mm bolt. Any bad connection in either plug can cause just about any issue. from bad transmission shifting, bad o2 sensor readings, no start, no...

www.explorerforum.com

 

[Turdle]

Also, verify the wire harness conversion is pinned out correctly. There may be some needed wiring changes using a year of harness with another year pcm
Just for clarity, this is a 99 pcm converted to work with 98 harness??

 

[Peoplesperson09]

I took everything from the 98 and put it on the 99 except the O2 sensors and the fuel rail fuel injectors

 

[J_C]

How much of the engine/parts were swapped over? Are you aware that '98 had a return fuel system operating around 35PSI but '99 had returnless system running at 65PSI?

This if you put a '98 engine into a '99 vehicle, you will need the '99 fuel rail and dampener instead of the '98 with fuel pressure regulator on it, and the '99 PCM... unless I'm misunderstanding, exactly which of these parts where mixed and matched how?

Okay a moment before I posted, you posted "everything", including fuel rail, but if you swapped the PCM then it's expecting it to be at 35PSI ?

Can you include the words engine and vehicle when referring to model years? Instead of "everything", tell us in a complete list, what everything is that has been done? I am still wondering about the fuel rail/pressure issue but didn't lookup your codes because the picture is sideways. Okay I rotated the pic, and it seems like you should have (might have been easier to?) reused the '99 harness and '99 PCM, and taken parts from the '99 engine to adapt the '98 engine to the '99 harness.

 

[Peoplesperson09]

I think I got rid of the mass air flow sensor now I'm down to the 2 02 sensors. I originally just cut the plugs and swapped them would the O2 sensor make this thing run rough stall out and die. Just made a video on utube. Search Peoplesperson09 ford explorer. Should be uploaded within 20 or so mins

 

[Peoplesperson09]

How much of the engine/parts were swapped over? Are you aware that '98 had a return fuel system operating around 35PSI but '99 had returnless system running at 65PSI?

This if you put a '98 engine into a '99 vehicle, you will need the '99 fuel rail and dampener instead of the '98 with fuel pressure regulator on it, and the '99 PCM... unless I'm misunderstanding, exactly which of these parts where mixed and matched how?

Okay a moment before I posted, you posted "everything", including fuel rail, but if you swapped the PCM then it's expecting it to be at 35PSI ?

From my understanding the fuel pressure is regulated via the fuel pump that's why I I kept the 99 injectors cuz they operate at a higher PSI

 

[Peoplesperson09]

The only reason I swapped the PCM was the 98 camshaft position sensor is a three wire and the 99 is a two wire I was afraid they wouldn't match up

 

[J_C]

The fuel pressure on a '99 is regulated by the fuel pump and the '99 PCM expects it to be 65PSI. It only has a dampener, not regulator on the end of the fuel rail.

The fuel pressure on a '98 is regulated by a regulator on the end of the '98 fuel rail (has no dampener instead) and dumps excess fuel back into the tank on a 2nd fuel line present on a '98 but not present on a '99. The '98 PCM expects 35PSI and adjusts injector duration accordingly. You might check fuel pressure and look at the long term fuel trims if you can keep it running long enough, or I might just be barking up the wrong tree!

Yes, keep using the '99 injectors, and the '99 fuel rail, and the '99 PCM, and swap any other parts from the '99 engine, needed to make the '99 wiring harness work is what I'm suggesting, IF that is possible.