Hi folks. I'm new here and I hope you can give me some info.

2002 Ranger 3.0 V6 auto, 33k miles. Never an engine problem until yesterday afternoon. Doing some errands. Shut down and re-started several times all with temperature in the normal range. On last start before heading home it started to run bad.

First indication was a shudder or jerk on the 1-2 upshift..was kind of subtle and I almost didn't notice. Next stoplight it was worse and then it started idling and running really rough with black smoke coming out of the exhaust. Obviously, I think, it had just suddenly started to run very rich.

Made it home (only about 3 miles) and it never stalled but the black smoke continued. No CEL. As bad as it was running I figured it had to set a code but no codes came up on my Innova 3100c. I did get a yellow light and a blinking EV status monitor (?).

Didn't have time to mess with it last night but when I started it up this morning the black smoke was gone and it was running like normal EXCEPT it would not rev over 3k either in gear or in park. Since I really need the truck next week I dropped it off at the dealer so they could look at it on Monday. Funny thing is that when I got there I put it in park and it rev'd to 4k+ just like good as new but I figured I better have them look at it anyway.

So what I'm curious about is what to expect. I've read on the forums that the FPR is a common culprit for a rich condition. Do these things usually fail suddenly? And what would cause the problem to appear after a day of normal driving and then disappear the next day...and maybe come back tomorrow?

 

Welcome to FTE.

Can the Innova 3100c read PID's ???? If so, what did it read the fuel pressure as????

How did the O2 sensors switching look????

Are you running a oiled foam or cotton gauze air filter???? If so had you recently cleaned & oiled it????

You said you didn't have any hard codes set, but did you look for any pending codes, that may be stored, but not matured to the point of setting a hard code yet????

Sounds like it was running rich & seeing as how it hasn't set a CEL, so you may be on the right track to suspect the FPR.

 

I'd suspect the cam sensor and synchronizer. The cam signal is dropping out at higher RPM's. The reason that it isn't setting a code is because the monitor gets disabled at RPM's higher than 2500RPM.

Usually when you experience rev-limiter type symptoms while driving, this is the cause. I think there's even a TSB on the issue.

I believe the fuel pressure regulator is built into your pump, and the part under the hood that looks like a regulator is just a dampener, with a vacuum hose attached so if it ruptures fuel doesn't leak all over the place. You might pull that hose just to be sure it isn't ruptured (look for gasoline), but I doubt that's your problem.

Good luck

 

Thanks for the reply PawPaw

The 3100c is a code reader, not a scanner so it doesn't list pending codes or fuel pressure, etc. Hopefully there is a pending code that the tech at the dealer can use to diagnose the problem and replace whatever is needed to avoid a repeat of the problem. My understanding is that running rich for very long will fry the cat converter.

The air filter is stock and doesn't have many miles on it, less than 5k. And like I said the rich condition came on suddenly and went away just as quickly so I don't see how a dirty air filter could cause that.

 

Thanks MazdaRAngerGuy.

Would the cam sensor typically experience an intermittant failure? The 3k limit occured after the rich condition cleared up and then went away a few miles later. My first thought was that running rich had messed up the cat and was restricting the exhaust but when I could subsequently rev higher I figured maybe I had just temporarily fouled the plugs. If the cam sensor is the problem is it a simple R&R or does it involve major work?

If you are correct and the FPR is in the tank with the pump I presume that will be somewhat more expensive parts and labor than if FPR was in the engine bay. Will have to look at my service manual later today.

 

The cam sensor is like most any other sensor, it can flake out, or the circuit can be damaged, which in both cases could cause intermmittent problems.

The 3.0L vulcan engine is somewhat prone to cam sensor/syncronizer isses. Replacing just the sensor is simple, replacing the whole synchronizer assembly is a little more challenging. See: https://www.ford-trucks.com/forums/2...placement.html

The FPR is indeed in the tank and your assumptions are correct: that equates to higher costs for labor and parts.

 

Well with regard to the air filter type question, I was thinking that maybe the MAF sensor could have been fouled up from over oiling those type of air filters, but seeing as how you don't use them, a oil fouled MAF isn't likely, BUT a otherwise misbehavng MAF may still belong on your suspect list, seeing as how the problem seems to be intermittent.

I kinda like MazdaRangerGuys idea about the fuel rail damper, so why not check the fuel rail damper's vacuum line & see if fuel is present. If so that would mean it's diaphragm likely has a problem & that could add unmetered fuel to the engine through it's vacuum line.

I think he's right about the fuel pressure regulator being part of the fuel pump & it's in the tank.

A scan tool that can read PID's or a fuel pressure gauge, that'll hook up to the fuel rail, will tattle on the fuel pressure regulator.

I suppose with the problem being intermittent, it could be a electrical connector problem with one of the systems sensors.

If you still have the vehicle handy, why not see if you can make loan of a scan tool, from a friend, or autoparts stores "Loan-A-Tool" service, that'll read PID's & look for any stored, or pending, trouble codes & monitor a few things like, fuel pressure, MAF sensor, O2 sensors switch rate, ect & see if you can spot anything unusual, while driving the vehicle when it's acting out.
Then post all the codes you find & any suspect component PID parameters.

If you don't have the vehicle, the Dealer will probably hook up his scan tool & get some clues, but he'll likely have to charge about an hours worth of labor.

Right now without some hints from a trouble code or two, everything is just a guess about why it's intermittently running rich.

Will be interesting to find out what is found, so keep us posted on what was done & the results.

 

I'm not familiar with your specific code reader, but most have the ability to show a snapshot... list of data stored in the computer's memory when the failure occured. If yours has this ability, you can force it to set a code.. try unplugging a downstream O2 sensor and drive it a few times until your check engine light comes on.. then you can check this list of data and see if anything looks.. out of line. Keep in mind the data list from this snapshot will be far from complete...

Saturns have a neat feature... if you flip the cruise on, off, on, off, on it will set a code that won't turn on the check engine light... this way when it's acting up you could do that and have a snapshot of what was going on at that time. Unfortunately as far as I know Fords don't have this feature.

Good luck

 

According to the manual for the Innova 3100c, a yellow LED (which I got) indicates either a pending code or a status monitor that has not finished its diagnostic self testing. If there is a pending code, there should be a numeric code and the word "pending." No pending codes showed up so the yellow LED indicated the status monitor issue as confirmed by a flashing EV icon for the Evap status monitor. Not sure if that is a possible cause of my problem or just a symptom.

We'll see what the dealer says tomorrow. The most puzzling thing to me is how it could run as rich as it was running ... the black smoke was pretty bad ... and have the computer not set some sort of code.

 

Update:

Well, the dealer checked it out and found nothing. No codes; no pending codes; nothing to indicate there had been a problem. They couldn't duplicate either the rich condition or the high rpm misfire during a road test (I know they drove it at least 5 miles, from odo reading).

I talked to the service tech when I picked it up yesterday and the only possible explanation we could think of was that on the day I had the problem I had filled the gas tank in the morning when it was cool. By afternoon when it was parked in the hot sun (black truck; 80+ degrees) the gas expanded enough to load the evap canister to the extent that when I started it that caused the rich condition which fouled the plugs and caused the high rpm miss. By the next day the evap was cleared and the plugs cleaned by a few miles of driving. Plausible ???? I would have thought the evap system would be designed to not let that happen (or that it otherwise would have happened before the other day since I've had the truck through several hot South Louisiana summers).

Anyway I guess it was a momentary glitch that has gone away for now. It ran fine last night and again this morning. I know I'll be more careful not to over fill the tank and maybe I'll not have the issue again.

Amazingly enough, the dealer did not charge anything to check it :-)

Thanks for your advice and opinions.

 

OK, good feedback & yes it's plausible that over filling the gas tank could do as they suspect.

I fill at a low or medium setting, until the pump shuts off, then round off the cents figure on the pump, so as not to overfill.

On a hot day the gas will expand a lot & it has to go somewhere, so now days the evap cannister gets tapped for the chore