I have a 99 ranger with the 2.5. Here are my ussues-1 rough idle but clears up when pressing pedal2 no power on flat ground, up hills or down
3 spark knocking like crazy
4 when first got it the cam shaft was 90 degrees out of time with crank
5 when removing wires from coil cylinder 2 offers no change in how truck runs however check plugs and it's burning fine no build up
This is what I've already done1 replaced IAC valve
2 replaced down stream o2 sensor
3 set timing to proper specks
4 replaced rear ABS sensor in rear end
5 replaced cat
Only code I'm getting is still saying bad speed sensor. I really like this truck but I'm close to scraping it because it's driving me crazy

 

Welcome to the forum

Lack of power would mean compression test would be warranted, just to take it off the table, waste of time and money trying to fix a compression issue with other parts

2.5l SOHC Lima engine should be 160+psi in each cylinder, if it gets much under 140psi power drops pretty quick

Engine would not run if cam was 90deg off, 10-15deg maybe, 1 or 2 teeth on cam timing gear

The 2.5l can be pingy(spark knock) from carbon build up or vacuum leak, vacuum leak should set a "lean" code

Do you also replace upstream O2 thats the main O2?
downstream just tests if Cats are working


After engine is warmed up
Let it idle and unplug the IAC Valves 2 wire connector
Idle should drop to 500 rpms or engine should stall
If idle doesn't drop then you have a vacuum leak

NEVER adjust the anti-diesel screw on the throttle linkage, it is NOT an idle screw, if you have adjusted it then say so and I will tell you how to reset it

 

Already done the IAC valve it's new and engine dies after warmed up. A little history about myself I am mechanically inclined and I know certain things are set and needed to make these engines run properly. I appreciate your help I've already gone over the most common recommendations provided here. I truly don't mean to come across as rud or anything like that. It's just iI've tried everything. Timing belt replaced, egr replaced IAC replaced checked timing 4 times truck runs and here is the really weird thing. Unplug the wires for cylinders 2 and 3 and there is no change in how truck runs no change at all. That's what's got me so ticked off I've spent over 1,000 bucks and nothing changed. . I just can't figure this **** thing out and it's a self pride thing now you know. It's beat me. Don't understand how it can run on only 2 cylinders but it does

 

Oh one more thing replaced the Rear abs sensor and.the only dtc code is saying that same sensor is still bad. Truck is for sale 1999 extra cab with only 120509 miles ton of new parts has custom wooden bed. Will post pics when gets day light. Unless I can get it running today on all 4

 

What brand of IAC Valve?
Motorcraft(Ford) or Hitachi are the only ones that work on Fords, the other brands seem to be stepper type and can be a real pain because they are "new" so should work but don't

And compression, hate to see you spend more money or trash it for a compression issue

Cylinders 2 and 3 are both at TDC at the same time, so the both are sparked at the same time and so share a coil in each coil pack

If you have a old timing light you can check for spark pulse on each, it would happen 180deg on crank pulley from 1/4 TDC timing mark

2 and 3 spark plugs are wired in series so pulling the wires doesn't really test any thing usually, because both should quit working in theory, lol

On the dual spark engine you can unplug the 3 wire connector on 1 coil pack and start the engine, that tests if all 4 spark plugs and the one working coil pack is indeed working
Repeat test using other coil pack
This engine ran fine for 14 years with just 4 spark plugs, the dual plug setup gives better performance, same as it does on the Dodge Hemi's

 

Well sir that may very well be the problem. The IAC I put on is a MasterCraft that the sales clerk at the parts store slipped by me because I requested Motorcraft. I will be speaking to him shortly. Why I didn't think of #2 and #3 cylinders firing off at same time is embarrassing for I knew that deep down in the lower memory bank of my brain. Let frustration cloud my thoughts. I truly appreciate you taking the time to talk with me and for giving such sound advice and helpful information. I will replace that with a new Motorcraft part today and also going to due full tune up even though plugs and wires have less than 500 miles found out yesterday that truck sat for 18 months before I purchased it and that the engine was installed right before parking it. Previous owner ran into this trouble after installing this engine which is out of a 2000 model that only has 58,000 documented miles on it. Let you know what happens. Oh and my timing light is a snap-on