1996 3.0L V-6 ... No power

[98v70dad]

My 96 ranger has started misfiring occasionally (when accelerating up a long grade) and it has way less power than usual for the last few months. It has new plugs (motorcraft) and wires (NGK) that have about 20,000 miles on them. I'm wondering if I need a new coil pack. Last night I disconnected each wire one at a time and looked at the arc. All of them are sparking but instead of being white blue they are all yellow-orange-ish. One of the sparks is much more orange than the others. The truck only has 75,000 miles on it but I know that the coil pack is original and I'm wondering if its getting weak and should be replaced. What can you tell me?

The part is pretty cheap and easy to replace so no big deal to throw a new one in there.

 

[98v70dad]

OK - so I replaced the coil pack with a new motorcraft part, I still have the same problem - no power and slow acceleration. The misfiring is better although not completely gone on a hill with the accelerator pushed down to the floor. I would really appreciate some help with this. I drive the truck 100 miles every day in freeway traffic. The slow acceleration is dangerous and I can't figure it out. Anybody?

 

[Uncle Gump]

It sounds a lot like a restricted exhaust...

 

[PetroleumJunkie412]

Not familiar with coil packs enough to be any help. This is a @RonD or @adsm08 question.

 

[rusty ol ranger]

Whens the last time you changed the fuel filter?

My 97 F250 460 did these same things when the filter was so plugged you could barely blow through it.

 

[98v70dad]

Whens the last time you changed the fuel filter?

My 97 F250 460 did these same things when the filter was so plugged you could barely blow through it.

Thanks. The fuel filter was changed about a18 months ago. Also done at that time was a new air filter, coolant flush, new plugs, new plug wires, new camshaft position sensor and the tower it sits on (it was broken), new emissions system purge valve and a new emissions purge flow sensor. I removed and cleaned the EGR and put on a new dpf sensor. Most of the new parts were motorcraft but nobody had the dfp senser so I bought whatever they happened to have. The camshaft position sensor may also be aftermarket - I usually buy SMP if they don't have motorcraft.

I cleaned the MAF by spraying it with MAF cleaner and cleaned out the throttle body also. I gradually replaced the trans fluid by sucking it out with a vacuum pump about 3.5L at a time and replacing, driving a week and repeating - slow way to do it but it works and is no mess. Used valvoline Mercon ATF fluid.

It ran pretty good for about 18 months. Now it barely wants to go....

 

[98v70dad]

It sounds a lot like a restricted exhaust...

I've thought about that - not sure. The truck only has around 75,000 miles on it. Would the restriction be from a plugged cat converter?

 

[98v70dad]

Other info is that I have no scanner codes. Is there a way to tell if its in limp mode? I'm wondering if I've got some sensor that sort of half works (no codes) but is bad enough that the computer went into limp mode.

 

[Uncle Gump]

You probably won't hit limp mode without a dtc.

google testing for restricted exhaust... usually done with a vacuum gauge.

Not saying it is the problem... just sounds like it to me. You said missing for the last few months... that a lot of fuel hitting the cats... it makes them really hot... it does happen.

 

[mikkelstuff]

I'm thinking camshaft synchronizer. My 2002 3.0L at 110,000 miles would miss sporadically when pushed hard but run 80 mph (across Wyoming) with no problem. I inherited the truck from my Dad who said it "always did that." Changing spark plugs, plug wires, and coil pack did not help. Changing out the cam synchronizer fixed the miss.

If changing the cam synchronizer, pay more for a Motorcraft. I first bought a much cheaper Dorman which never made it a year.

 

[adsm08]

The single cylinder that looked oranger than the rest, pull that plug and inspect it. I have had MC spark plug insulators crack in the first 5K miles.

 

[98v70dad]

I'm thinking camshaft synchronizer. My 2002 3.0L at 110,000 miles would miss sporadically when pushed hard but run 80 mph (across Wyoming) with no problem. I inherited the truck from my Dad who said it "always did that." Changing spark plugs, plug wires, and coil pack did not help. Changing out the cam synchronizer fixed the miss.

If changing the cam synchronizer, pay more for a Motorcraft. I first bought a much cheaper Dorman which never made it a year.

I was going to check it and see what I bought. I buy motorcraft if they have it. The truck is my daily driver so if something is broken or breaks while I'm working on it I have to get something in order to get to work. I don;t like buying crap parts but some times there's no choice.

 

[98v70dad]

The single cylinder that looked oranger than the rest, pull that plug and inspect it. I have had MC spark plug insulators crack in the first 5K miles.

Thanks. I have a some new plugs I was going to put in. I was going to pull the plugs today but I lost my gap tool and nobody had what I wanted - wire gauge with 0.044 wire. Plenty of coin gauges to pick from - not so good for platinum tipped plugs.

 

[98v70dad]

You probably won't hit limp mode without a dtc.

google testing for restricted exhaust... usually done with a vacuum gauge.

Not saying it is the problem... just sounds like it to me. You said missing for the last few months... that a lot of fuel hitting the cats... it makes them really hot... it does happen.

Could be _ I'll check it out, thanks. The truck only misses when I push it hard on a hot day with the AC running going up a grade so its not missing very often or for very long.