Ranger Misfires and idles rough!!

[FordPower3.0]

Hi i have a 99 Ranger 3.0 flex fuel and i recently replaced the plugs and wires still nothing seems to fix the misfire and i used a spark tester and seems all of the cylinders are firing and if i rev the car it misses bad and has no power i got the compression check done everything seems to be fine. Any ideas out there what else i can do to check this problem out and resolve it???

 

[Rearanger]

Have you tried to access a trouble code? Is the misfire with/without e85?

 

[Dave99]

check the fuel pressure and the exhaust...i had an 89' and a 93' that had similar problems, fuel filter on one and cat was semi plugged on the other.

 

[tomw]

Have you cleaned the MAF? If you have a problem, there should be some codes stored. A MAF that is clotted can make the engine miss and lack power as the computer doesn't know the amount of air being ingested, and can thus send the wrong amount of fuel.
I am assuming you have checked and double checked the plug wire installation. It's easy to cross wires, and anyone who claims they 'never did that' is likely to have their nose grow longer...
Spark, air, fuel. Remember that's all you need. If you have compression, likely a 125 on the low end, spark and fuel, it should run. A coil can cause misfire also, so I'd put a timing light on each plug wire with the engine running and look for dropout in the flashes.
tom

 

[Big Jim M]

Yep!

Have you cleaned the MAF? If you have a problem, there should be some codes stored. A MAF that is clotted can make the engine miss and lack power as the computer doesn't know the amount of air being ingested, and can thus send the wrong amount of fuel.
I am assuming you have checked and double checked the plug wire installation. It's easy to cross wires, and anyone who claims they 'never did that' is likely to have their nose grow longer...
Spark, air, fuel. Remember that's all you need. If you have compression, likely a 125 on the low end, spark and fuel, it should run. A coil can cause misfire also, so I'd put a timing light on each plug wire with the engine running and look for dropout in the flashes.
tom

I done it! More than once too.. Over the years there has been so many combinations of just where in the Hell #2 plug is, sometimes it's hard to get a grip on where each wire goes.. Even if you THINK you know... sometimes it's just wrong.
Big JIm

 

[JP02XLT]

It is also an known issue that there are I believe 3 different coil packs for a 3.0, and the wire location per cylinder is different on 1 of the coils, 1 also has a different electrical connector. So if you have changed coils or had the wires off that could be an issue as well. A member on RPS chased a similar problem after a "tune up" & coil pack change, finally nailed it down to firing out of sequence, it would idle fairly well, but had no power and missed like crazy when you rev it.

JP02XLT