OT: 3.0 V6 sick

[Anonymous-0]

Well gang I'm about out of ideas on this one. I've got a 2000 Ranger with a 3.0 V6 that is running badly. It idles rough and has lost what little power it had on the road. Fuel mileage has dropped down to around 10mpg. Took it to a mechanic acquaintence and he put a scanner on it. Showed a missfire condition on cyl. 4 & 6. So I replaced the spark plugs, plug wires, fuel filter and later the coil pack. None of that helped. Took it back to him again to read the codes. The only thing it showed was a misfire condition (but this time it would not specify the cylinders) and that the differential pressure sensor was out of limits. This is the sensor that controls the EGR valve. So I replaced that. No improvement. This truck has an O2 sensor after the catylitic converter. He told me that if the converter was starting to go it would show up on that O2 sensor. Will it? Next I got to thinking about the injectors. Found a place in Washington that will test, clean and refurbish injectors for $17ea. My injectors new cost $80ea. So I pulled all of them and sent them off. Testing showed that they were not that bad and cleaning made them better. I put it all back together last night and no improvement. While I had it apart I looked at the EGR valve and it looked clean. I didn't find any vacuum lines broken or off. I have sprayed around the engine with brake cleaner to try and find a vacuum leak. The vacuum only tests at 12 inches at an idle and is very shakey. It does come up some if I raise the engine rpm. I think that the vacuum is that low because of the rough idle, but I'm not positive. I think I will take a compression test on it tonight. Any ideas???

 

[Revredneck]

It sounds to me like your exhaust is plugging up. The catalytic converter is the most likely candidate. Loosen the pipes at the manifolds and see what your vacuum gage reads. You might even drive it for a short distance and see if it improves. There are more technical ways to test it, but that way is easiest.
Good Luck and God Bless,
Tommy

 

[Anonymous-0]

I have 2 suggestions, first is rather than throwing parts at it, take it to a dealer and let them fix it. If you prefer not to do that go to www.therangerstation.com there is a pretty sharp bunch of guys there.

 

[twopop]

my 88 2.9 was giving me fits with a flooding problem. three shops and no help.finally changed the o2 sensor and fixed.I agree about the catalictic converter,and that the o2 sensor helps plug it up

 

[dhermesc]

A Ford dealer fix a problem that doesn't show up on a computer? You got to be kidding me. You'll pay two "mechanics" $60.00 an hour to scratch their heads and their ***es for 4 hours to tell you that's how it runs.

Trust me, I've been there in more than one Ford dealership.

 

[Bob]

The compression check is a good idea. Let us know what you find.

 

[bradk]

Flex fuel? If so,are you sticking to one fuel or the other? I would want to see the live data.Specifically the long and short term fuel trims and the 02 sensors voltage.

Does your friend's scanner have reading capabilities?

 

[Anonymous-0]

He was able to get real time data as the truck was running. I'm not sure what all of the readings were. He just told me that the O2 sensors were reading okay. I do remember seeing readings changing at different throttle levels though.

 

[Howard H.]

What color is the exhaust??

I had a Ford pickup that went to a lot of black exhaust and running like you described when the fuel pressure regulator failed.

Had a V6 T-bird that blew a head gasket and running like you said with white smoke exhaust...


HH

 

[Anonymous-0]

Yes it is a flex fuel, but I don't run 85e in it. I have run the low percentage ethanol in it though. 10% maybe?

 

[Anonymous-0]

It doesn't smoke and the tailpipe isn't sooty. It doesn't burn any water or oil either. I haven't checked fuel pressure yet so that's a good idea. I know it will hold pressure because I got a little bit of spray out of the shreider valve on the fuel rail after shutting off the engine and letting it set for a couple of minutes.

 

[onefarmer]

With a low vacuum reading and low milage leads me to think pluged converter. I'd pull the O2 sensor that is ahead of the converter or loosen a connection and take a reading.

Also do a compression test.

My 95 F150 was giving egr error readings and would sometimes go into limpin mode (really rich, second gear only, no power) I grabbed up the torch and cut a patchable hole ahead of the converter and it all cleared up.

 

[Howard H.]

One time on our Suburban, it also would spray fuel out the valve, but the pressure was not close enough to being correct to even run.

Does the exhaust smell like gasoline??

There's no chance the plug wires are out of sequence, is there??

Let us know what you find - I like tucking away all these stories for ideas when trouble comes!


HH

 

[Anonymous-0]

Is it the (E) SOHC or the (X) push rod engine?
How many miles?
Do a compression check to verify cam timing if it is an SHOC. Chain could have jumped time.

 

[Anonymous-0]

A couple of other things to check. A plugged fuel filter causing low fuel pressure in the fuel injection system. Check fuel pressure at the rail. If fuel pump is worn providing low fuel pressure to the fuel injectors it will also loose power. Seems dumb but must add that a plugged air filter will not allow the proper amount of air into the engine.

 

[Anonymous-0]

Sorry about previous post I just realized you said 3.0 Liter not 4.0 liter.

 

[Anonymous-0]

I have replaced the fuel filter with no change in performance. I also thought of the air filter. In fact that was one of the first things I checked. It has one of those washable K&N style filters. I cleaned it up really good and no luck there either. In fact one day after a lot of rain so that there was no dust in the air I tried driving it down the interstate for a ways with no air filter at all. Still no change.

 

[Anonymous-0]

I have a 96 chevy blazer that did the same thing The dealer replaced plugs wires dist. cap fuel pump and did not fix it still had a multible cylinder missfire they said it had to be internal charge me $1500 and wanted to put in a new engine I said I would drive it till it blew up only had 51000 miles on it They would not warrenty it .I then took it to an independent machanic and he replaced I think the CAM sensor if it wasn't The cam sensor it was the CRANK SENSOR . It runs like new and only cost $65

 

[Anonymous-0]

I've wondered about that myself. This motor has something where the distributer should be. A small plastic deal with wires coming out of it. I assume it is a type of magnetic pickup for ignition timing, but I haven't dug into that yet. The experience that I've had in the past with a magnetic pickup is that it is good or bad. Good motor runs. Bad motor has no ignition. I suppose it could be bad, but not completely dead.

 

[Anonymous-0]

Contaminated mass air flow sensor. The K&N filter passes a lot more dirt that a Motorcraft filter and that mass air flow sensor is sensitive to dirt and then it makes the engine run lean.

Two years ago a Ford V-8 mass air flow sensor was $375 less a $75 core if I recall correctly. Today at NAPA its more like $120 and they have some magic cleaning elixur, I've heard.

Gerald J.

 

[Anonymous-0]

Would contact cleaner for electronic parts work to clean the coils on it? I looked at it to make sure there was no visible contamination, but small stuff might be hard to see.

 

[Anonymous-0]

Contact cleaners tend to leave a residue to slow corrosion of contacts. That will gather dirt and make the MAF get dirty quicker.

One Ford garage did clean mine and it ran for a year. The engine smelled like carburetor and fuel injector spray cleaner. The sensing parts are platinum wires and are very delicate.

I've heard that NAPA has a product probably from CRC espially made for the purpose of cleaning MAF. Now that I'm running on a new MAF with a new Motorcraft filter, I've not looked for that cleaner.

If you break one of the wires in the MAF, you are walking until you buy a new one. I'm not sure the computer showed anything for the contaminated MAF either. Certainly there was no consistent check engine light.

Gerald J.

 

[02XLT4X4]

The K&N will also get oil on the MAF if you put a tad too much on when you clean it. The advantages of those things are few and far between.

 

[Anonymous-0]

The sensor tells the computer when to fire and when to advance or retard fire and I was told when they get bad they most of the time retard fire before they go dead.