Same problem different Engine....Need help...

[2003Ford3.0Vulcan]

Hello
So as my luck would have it I have a weird ordeal. Let me rewind and give a bit of history on the rig. 2003 Ford Ranger 3.0L Vulcan V6 Flex fuel with around 120K on the clock. The engine was neglected and retired early. The last shop it went to said it needed an engine. It initially went in for a Check engine light staying on Cylinder 1 Misfire. So that said it has had an engine replacement. I installed new coil, plugs, wires, cam syncronizer and IAC all Motorcraft parts. I broke the engine in and on the rigs first road test I am stuck again with the same check engine light cylinder 1 misfire. The engine ran a little rough on initial start up I got the cam syncronizer dialed in at 38* as the service literature says it smoothed out a little bit. The test drive went fair but the check engine light was really discerning. I dont know if that running rough is part of the relearn process or what. Now I made sure the plug wires were on the right coil tower and going to the right plugs. I am kinda lost with this one. Literally all that money spent on the engine and it runs the same as the old one did. Fuel system has been kept up new fuel, new filter and fuel dampener. I am curious as to what any thoughts on this might be...? Could it be the PCM...? That is the only variable left I think. Any insight from the Ford Ranger gurus would be greatly appreciated. Thank you for your time.

 

[RonD]

Welcome to the forum

I think this should go back to the shop that did the engine or the place the engine came from
No, it would be hard for computer to cause ONLY #1 misfire, 1 and 5 BOTH use same spark
#1 injector could be bad, or its ground wire to computer

I don't quite follow that YOU put in new plugs and coil pack?
Why?

Where did the "new" engine come from?
Or is it just "another" 3.0l engine?

When there is a misfire on any engine the first thing you do is a compression test
All spark plugs removed
Test each cylinder and write down results

You do this first because if it IS a compression issue you will waste time and money on spark and fuel
Compression is mechanical, so good or bad there is no real "grey" area
The 2004-2006 3.0l's did have valve seat issues, and 2003 could as well as 2007

So do compression test FIRST

 

[2003Ford3.0Vulcan]

Thank you for the reply, I took the rig to a shop and they said it was in need of an engine. Due to finances and I pulled the engine and got a remanufactured engine from Summit. I looked it over before putting the tins on and saw fresh crosshatch and machine work. Torque check on the fasteners and all seemed in order. I put the tins on and married it up to the transmission. Did the install. All harness marked before removal so all went back in corresponding places. I put the stuff on the rig. I understand the concept of checking compression first as it is mechanical and like you say it is what it is no grey area. I will double check that when time permits. I just find it so weird that the engine is running the same as the old one did with the same check engine fault.