Hello Guys, new here. This is my first post! Been lurking for a bit but I just picked up my third Ranger and I'm in a pickle. It's a nice, 1999 2.5 litre with 278k miles on it 1.6k of them belonging to me. Purchased it for $200, needed a fuel pump. I work in a shop, mainly at a GST/C tech level so I know some basics. The issue follows!

I recently changed the fuel pump, both coils and all the plugs and wires. What lead to me changing the plugs and wires was the vehicle running rough as hell, losing power and just cutting off while driving. I ended up dropping the gas tank again, cleaning it completely and getting fresh gas. I also checked the injectors they were all reading at 14.7 ohms. None obviously bad. After reinstalling the tank I put injector cleaner in the half tank of gas and just kept the rpms up for a few minutes. After I let her idle down she ran beautifully. It smoothed out it wouldn't big down or die out on application of the throttle. It ran nice.

Welp, that was 3 days ago and now when I shift into gear it's sputtering again. It almost feels like a clogged cat but I know it isn't that. I have no experience on this engines and it seems like they're isn't alot of info out there on them. I'm wondering if I should just tear the upper manifold off and replace those injectors. I can get them for a decent price offline and I would like to replace the plenum gasket too. Could my issue still be injectors despite them measuring good ohms wise?

Thanks fellas. Sorry for the long one. This is by far my favorite ranger that I've owned. It's fun to drive. Just put new tires on it and I'd really like to see what she can do this winter. Any help at all is appreciated.

 

Welcome to the forum, first post

2.5l SOHC Lima engine is exactly the same engine as the 2.3l SOHC Lima used in Fords since 1974, so loads of info on them

2.5L just has longer connecting rods and different crank, so a Stroked 2.3l, it was only used for 3.5 years, 1998 to 2001.5, so yes 2.5l searches won't turn up much

One of the benefits of the dual spark plugs is that the engine can run on just 4 on one coil pack, so you can test spark plugs and coils that way
Both spark plugs, in each cylinder, fire at the same time for better performance

Unplug either coil pack's 3 wire connector, start engine, see if there is a misfire
Then reverse it, use the other spark plugs and coil pack

Its good to test injector OHMs but it will only show a bad coil inside the injector, if injector is clogged up it will still test OK, but would cause steady misfire, not random misfires(multiple cylinders), you can usually tell the difference

Use a vacuum gauge to test if exhaust might be clogged

Compression test is always a good FIRST test, these are black and white, so once its taken off the table you can safely spend time and money on spark and fuel, lol.
If there is a compression issue you can waste alot of time and MONEY on non-fixes
Yes, new plugs will work great in a lower compression cylinder, then start to misfire, i.e. the 3 days
So don't assume compression is OK, best to test it and forget it, or............fix it

 

Hey Ron,

Thanks for the info. I did check the compression on each cylinder when I pulled the plugs. Everything was good on that end. I drilled a hole behind and in front of the cat and installed a pressure gauge and it seemed to be flowing fine. I was thinking perhaps it may be clogged injectors. No telling when they were last changed. When I ran the cleaner through after putting new gas and filter on it, it ran better than it has since I owned it but now it's acting up again. I might just through some injectors at it since I've ruled out coils, compression, plugs and wires.

 

Any running difference when cold(open loop) and after warm up(closed loop)?

 

There's always the possibility that the cleaner knocked something loose, and it clogged up a new hole...

More cleaner, and running WFO up a hill a few times, might blow it through...

I would give it an extra strong dose of Techron, or Lucas, or whatever your favorite flavor is... And then run it hard! Look for hills where you can floor it.

WFO throttle, under load, might clear it all out. You want to have the revs up, but she's gotta be under load too.