Fuel MIXTURE seems to vary ALL OVER the place!...??

[fixizin]

Started out as this "ROUGH AS CRAP" below 2200 RPM problem...

http://therangerstation.com/forums/showthread.php?t=161830

... which was "improving" over time, i.e. only having to drive 3 miles until it "smoothed out", instead of 5... this MIGHT have been due to running E85, and then PREMium 91 octane (E10)

... and let me admit that the lack of a CEL/MIL has caused me to procrastinate pulling OBD-II codes... my bad. The fact that it fires right up every time I turn the key also lulled me into "wait and see"...

... THEN I said, oh, let's go back to UNL-Regular 87 (E10)...

But now it's rough up to 3,000 RPM, and even HIGHER, and after driving just 5 miles, some portion of the exhaust system is getting so hot, I can smell "something burning"... gotta be super-LEAN, eh? Afraid to drive it much farther.

After sitting 24 hours, fired it up and let it idle, and the exhaust was clear, but reeked of RAW gasoline = super RICH, eh? WTH?

Summary: seems to run best (not perfect) on Premium 91, second best on E85 (90 octane??), and UNdriveable on Regular 87... ??


>>> Could one or more Oxygen / O2 Sensors cause this?

Will finally drive the 3 blocks to auto parts store for some code dumping tomorrow... should be able to watch it go thru most of the cold-start (91 degF outside) to hot-running progression... HMMMmmmm...

 

[RonD]

Catalytic converter will get very hot if exhaust is rich, cat converter is there to complete the fuel burn off, rich means extra fuel to burn off and cat can get red hot.
Lean makes cylinder hotter and can cause pinging/knocking because fuel/air mix pre-ignites from the extra heat

You could have an injector that is leaking.

Or yes, an O2 sensor that is misreading Oxygen level in exhaust causing rich mix.

You can get OBDII readers that work with smartphone or laptop via bluetooth, usually under $40, they work for any vehicle made after 1995/96, so not just for Ranger or Ford.
This will give you real time data while driving and can help ID a problem better.

Just to test if you do have a leaking injector:
have engine warmed up
Key off
push gas pedal to the floor and hold it down all the way
turn key on
try to start engine, it should NOT start or even fire a little
If it does then you do have fuel leaking in to intake

Computer has Clear Flooded Engine Mode
0 RPMs(engine off), gas pedal to floor(TPS 4.5volts) = turn off fuel injectors to clear flooded engine

As soon as you release gas pedal injectors will start again

 

[fixizin]

RonD, I read your Engine FLooded Mode test in another thread and my truck DOES pass that--not a single snap, crackle, or pop--as if all the plugs were pulled!

Also didn't know the catalytic could actually keep up the reaction-rate well into the super-rich zone... still, probably not healthy for that expensive (dual) component.

Hope all that extra fuel isn't breaking down my first-ever crankcase full of SYNthetic oil... durn.


Will return with codes...



PS: put RonD on da PAYROLL... he's worth way more than any Chilton or Haynes manual!

 

[fixizin]

... and yes an OBD-II reader that makes use of an existing interface (e.g. smartphone) makes more $$ sense than a dedicated type with its own housing, etc... will be shopping... can't expect to keep a '99 on the road without DIAGNOSTIC VIGILANCE!

 

[fixizin]

OK, the lazy know-nothings at Advanced will only do a read with the Key-on-engine-Off...

... that only pulled up a P0302, Cyl 2 misfire, which would explain the new roughness at all RPMs... that's the one Autolite Copper plug I've been meaning to replace with the OEM Motorcraft Platinum type... d'oh...

... probably time to pop on that new Bosch ignition harness I have in storage.



Will borrow high-end reader later in the week, and look at run-time parameters, O2, fuel trims, etc.

PS: Every time I mention to random neighbors that the catalytic is running hot due to rich mixture, etc., everyone says "oh, your catalytic is CLOGGED"...

 

[RonD]

A $25 vacuum gauge is also a nice tool to have in the box, works for any gasoline engine to diagnose engine health, and clogged exhaust

Good read here: http://www.gregsengine.com/using-a-vacuum-gauge.html

If you raise rpms to 2,000 and hold it steady vacuum should hold steady as well, if it starts to drop exhaust is restricted

 

[cowboycowboy91]

Don't underestimate the MAF sensor...

I am new to this forum and possibly don't know as much as alot of people on here, but the MAF sensor can cause crazy rich idles and crazy lean revs...I know you said that the plug was crap in cylinder 2, which would be for sure a rough idle issue, but if the flooding or lean problems continue, time to pull out the ohmmeter and check the MAF sensor...with engine off and key on, check the first wire on the right...should be 4 wires going into MAF (unless it has air intake sensor built into it, then 6 wires, but it should be 4 on a early 2000's or before). The first wire should read 12. The next is a ground...put the ground wire of tester on this wire and the other on the battery and you should get 12 volts..the third is a ground through the ecm...it can be tested the same, but I would bypass it because it can damage ECM. The last wire you test running and the black ground wire of tester connected to negative terminal of the battery. The voltage on this wire should vary with engine rpms. What to look for is erradic voltage jumps without increased idle or no variation at all. I should also say this as a disclaimer...I have NOT tested a MAF sensor on a ranger with this method and I would double check a wiring schematic before running this test, but basically once the wires are identified as what they go to, this test can be safely performed with little to no special tools. The volage should increase with rpms and decrease with lower rpms...anything contrary to this means the MAF should be taken out and inspected and cleaned with some MAF sensor cleaner...if the voltage is still crazy...then its time to replace the MAF. Hope I helped and good luck friend.

 

[csargents1546]

Another issue is if you where running e85. Then switched to regular, the flex fuel inferred might be still on e85 as far as the computer is concerned. As inexpensive as injector are, I would replace th all. Make sure they are flex fuel if that is what your truck was meant to burn. Can cause a whole bunch of head ache if the wrong injectors are installed. Good luck.

 

[fixizin]

... As inexpensive as injector are, I would replace th all.

I guess if by "cheap" you mean approx. $220-$360(!) for a "six pack" of injectors then

I'm not replacing anything that's not end of life...

I mean we already have Obummer and his Commie Clan driving the price of even mediocre 3-4 year car batteries up to $140 with their phony regulations on lead smelters... i.e. you're basically RENTING your battery for $3/month!

 

[fixizin]

ALL-righhhhty then... one new Motorcraft Double Platinum sparkie (gapped .044") into Cyl 2, a smear of anti-seize, and a new Bosch plug wire, and she be smooth runnin' again--tailpipe smells normal, catalytics not glowing in the dark... (you'd THINK the ECM firmware would be smart enough to stop injecting fuel into a non-sparking cylinder, eh wot?... )

... the other 5 factory/OEM platinum plugs have never been pulled, and I'm planning to let them go to 100k miles, or at least 60k, eh? Since the #2 wire is the only one that's ever been tugged on (8 years ago), that's probably why it failed first, but the remaining 5 wires will be replaced shortly--nice Bosch set from Rock Auto, already has the clear grease in the connectors.

... duh 49-month-old Advanced Auto "Silver" battery seems to be on its way out, but that seems to be an independent issue. Got a line on Motorcraft batteries at the same (Obama-inflated) price as the generic crap. Sears Die-Hard even less--not sure how crappy they've gotten...?

>>> BATTery REPlacement = good chance to reset the ECM parameters

Will have a high-end (even does OBD-I) scanner later this week... what should I be looking for, i.e. Fuel Trims, O2 sensor readings, etc.??

 

[enjr44]

Just an FYI,
I have heard great things for a long time about Motorcraft batteries. So when I decided to replace my 11 year old original battery before it left me high and dry I decided I wanted and got the same part number Motorcraft.

Been a couple of years now and the at rest battery voltage is down around 12.2 volts, not a good sign. It always starts and charges; but, 12.2 volts is an indication that it is aging fast. Here in western WA, with our mild climate, batteries usually last 8 to 10 years. Maybe just a one off dud!!

 

[fixizin]

Thank you for the real-life feedback enjr44... and while the conventional wisdom on American vehicles is that the tires and batteries installed at the factory are 2nd-rate (and indeed my '99 Ranger did come with the infamous "Exploding Firestones"), my original battery lasted 7 or 8 years (low-mileage years to be sure), all in the HOT climates of NV, AZ, and So-FL...

... then I fell into the "get it from Advanced, there's one on every corner, and they install it for you, i.e. core charge refunded, all in one stop" ... NOT impressed with their dead-in-4-years no-pro-rated shyt... plus the fubar "tech" put my battery jacket on backwards the last time...

... might go with the DieHard... always wondered what happened to the sealed maintenance free breeds... looks like Sears still has some.