Ranger sat for a while.... Engine now rough?

[twintips_16]

Hello everyone! I have just purchased my first Ranger(98 2.5L fleet truck) to add to my truck collection(Screw and Powerstroke). I purchased this a month ago on the premise that it would be a get around little truck to drive to work and back to save wear and tear on my screw. When i bought it the owner said it ran when he parked it (2 years ago) and that it didn't run now. And to boot, even if i got it running it wouldn't drive as there were issues with the clutch.

I was able to get it running in his yard and it sounded ok with a little miss. But i never got to drive it. I trailered it home and pulled the tranny to find a bad slave cylinder. Replaced that and then it was time for the open road!!!

Right off the bat i noticed it had a slight power issue. Not huge but it was there. I drove it for a day and got all the bugs out of it and old fuel. When i bought it the guy gave me a full set(8) of autolight plugs that were brand new and a couple of oil filters and quarts of oil he was using. So me being the guy i am went home and proceeded to change the oil and replace spark plugs. I dont know which is worse, my 5,4 or this.....

Anyways as i was doing this i also checked the air filter and i was going to replace the wires but the set on there look like they arnt that old and he said he did plugs and wires 30,000. The plugs i pulled were in ok shape but were wearing uneven on one side of the electrode.

Still im having a miss and i cant find it. I have since put 300 miles on it thinking that if i work it loose it might work better. I just went through my first tank almost all highway driving and it bot 20.6 mpg's. When i talk to the guy at work who has the same exact truck(6 months apart in build date) he says he gets about 28 doing the same driving.

When im on the high way i struggle to get up to 65 and maintain 65 in 5th gear. But it seems as the engine warms up it gets a little more power as im able to creep up to 75 after the coolant gauge goes up. He came up with the idea to start swapping easy stuff on both trucks till his ran worse and mine ran better. We did the EGR valve and coil packs. No change.

Where would you guys start looking? Is there any common problems with this truck that might cause it? When at idle it is kind of rough. At 1000 RPM's it purrs. Driving around town is good to go. But it is power less on the highway and struggles to get above 55. But it climbs right to 55 no problem.

Thanks in advance!!!

 

[mp3deviant721]

Check engine light on? I'd start there if it is. Possible plugged cat too by the sounds of it.

GS³: Carbonized, leanKernel'd, Philz'd
Have a Doki Doki ☆ Morning!! ?

 

[twintips_16]

Check engine light on? I'd start there if it is. Possible plugged cat too by the sounds of it.

GS³: Carbonized, leanKernel'd, Philz'd
Have a Doki Doki ☆ Morning!! ��

Thats what I was hoping to do. Twice i have gotten the CEL to flash briefly. Very briefly. Then it goes away. I have hooked a scanner to it and 7 out of 8 readieness checks are compleated and it has no codes or fualts.

I was hoping to push it to throw a code then it would make life easy. But its so subtle that it isn't happening.

 

[twintips_16]

Also, both times it threw the CEL breifly were going up the same hill in forth gear at 50mph. It seems to stumble at heavly load low RPM more then any other area. I think that is what is contributiing to the low, high speed, power issues.

 

[mp3deviant721]

Seeing as the CEL is flashing, you are for sure chasing a misfire...

If you have done plugs, I'd check the wires, someone saying the wires have been done 30k miles ago doesn't necessarily mean they are good. Injectors can cause misfires as well. I'd ohm them out for kicks. Maybe even listen to them with a stethoscope to see of they sound different.

GS³: Carbonized, leanKernel'd, Philz'd
Have a Doki Doki ☆ Morning!! ?

 

[tomw]

I would check the fuel pressure and deliver, make sure the MAF is clean, and take a look at the plug wires with the engine idling after dark. If you lack fuel, it will cause you to press the pedal, and the computer might be putting the mix 'rich' in an attempt to make up for it. The MAF will mis-report how much air is coming in, and confuse the computer if the outgoing exhaust gas is up/down on O2s floating around. Bad plug wires would/could give a slight light show in darkness if they were cross-firing or arcing to ground.
If you have a scanner, take a look at the fuel trims and if weird, mention that.
Does it require a long crank time before firing, or does it have a good idle from the get-go? Any other reportable quirks?
tom