stalled on highway, won't start, need FF info

[pjtoledo]

Updated: stalled on highway, won't start, need FF info

This is a continuation of my 2000 Ranger blues. Its a 2000 3.0 FF 4wd atx, 'bout 72,xxx miles. Couple of weeks ago whilst crusing up towards Ann Arbor it started bucking and stalled out within 2 miles. Did the obligatory wait 15 then crank, wait another 15 and it still wouldn't start. Had it towed to a Ford dealer near my place who diagnosed it as a bad/shorted flex fuel sensor. The sensor is a dealer only part, and lists for about $660. I declined the repair, paid the diagnostic fee and towed it home. For grins and giggles I replaced the cam sync sensor, no change in symptoms, still chugs then stalls. The metal tab under the sensor only moves a couple thousandths then has a solid click either way, so I don't think the syncro gizmo stripped the pin.

Any way, back to the f'in FF sensor. Rigged up a breakout harness and crawled under the truck with an O'scope today. Measured 12v on the blue/orange wire, ground on the black wire, and a digital output on the green/lite green wire. That digital output was at 5v and had a pulse going down to about 2v every 6ms. The signal was hi for about 5.5ms, then low for .5ms. Hmmm, that's a 10% pulse, and I'm using plain 'ol 87 regular in it. If I were one to make assumptions, I would assume that a 10% pulse may correspond to 10% or less alcohol fuel in the system.
Problem is, another site states 40-60 hertz signal for gas, 60-100 for 30% methanol, and 90-130 for 60% methanol. The 6ms I measured translates to about 166 hertz. And do methanol and ethanol read the same in the sensor???


So, my questions are:

1. is a .5 ms pulse on a 6 ms cycle correct for gas with less than 10% alcohol?

2. where does the dark green / with lite green stripe wire go?


Time to head out and rent a scanner, see what the pcm thinks is wrong.




Perry

installed replicator today, fired right up.

 

[adsm08]

Ok, the flex fuel sensor tests the conductivity, temp, and dielectric constant (what ever that is) of the fuel and outputs this as a duty cycle in -/+ .5 increments. 51 hz =0% alchohol, 67 Hz = 25%, 89 hz = 50% and 115 hz = 85% (Ford's numbers).

Your dark and light green wire is the FF sensor signal to the PCM.

Goes to the PCM connector, pin 34.

Check for 10.5V+ key on, on the hot wire (left side looking into the connector, off-centered little slot down) it yes, check for continuity to ground if none, unplug the PCM and check continuity from the FF connector, center wire to PCM pin 34 (pins numbered on the red face at the ends of the rows), if none, check continuity to ground from FF connector, center wire, if none test gets complicated and required scan tools.

If you get to that point in the test and still haven't found anything wrong, let us know and I'll put up more of it.

 

[pjtoledo]

Ok, the flex fuel sensor tests the conductivity, temp, and dielectric constant (what ever that is) of the fuel and outputs this as a duty cycle in -/+ .5 increments. 51 hz =0% alchohol, 67 Hz = 25%, 89 hz = 50% and 115 hz = 85% (Ford's numbers).

Your dark and light green wire is the FF sensor signal to the PCM.

Goes to the PCM connector, pin 34.

Check for 10.5V+ key on, on the hot wire (left side looking into the connector, off-centered little slot down) it yes, check for continuity to ground if none, unplug the PCM and check continuity from the FF connector, center wire to PCM pin 34 (pins numbered on the red face at the ends of the rows), if none, check continuity to ground from FF connector, center wire, if none test gets complicated and required scan tools.

If you get to that point in the test and still haven't found anything wrong, let us know and I'll put up more of it.

Hmmm, according to my voltmeter:


first pin, above key, is ground, black wire
middle pin, 12v, dark blue with 2 orange stripes
pin farthest from the key, output, dark green with 2 lite green stripes



I was able to measure 12v and ground at the connector while is was disconnected fromm the sensor, I may want to double check for actual zero on ground, the frame was a bit rusty there.



Managed to get an O scope on the output, here's what I got


-_----------_----------_---------_----------_

the period from pulse start to the next pulse start was 6 ms, that equates to about 166HZ, the upper is 5v and 5.5ms in duration, the low pulses are about 2 volts and .5 ms duration. I'd sure like to see aknown good signal, mine doesn't exactly look like something you would measure in frequency.
I'll check pin 34 at the PCM tomorrow, also rent a scanner and check codes.
Until now I was going by a dealers diagnosis of a "shorted" sensor.
Thanks much


Perry

 

[adsm08]

Well 5 volt on the signal line is appropriate. Since the mid 90s Ford has used a 5V reference voltage for the sensor signals since it lessens the effects of driving on the battery since 5V is the point where the engine just won't run at all.

a 166 Hz signal from the FFS signal line would equate to 100% alcohol which actually matches your symptom very well since it would basically be flooding the engine with fuel trying to achieve a stoich ratio for pure alcohol (somewhere in the area of 6 or 7:1 as opposed to the 14.7:1 air/fuel ratio for pure gasoline).

You are right on the pins, I had a dyslexic moment there and flipped the power and signal when I typed that. Center pin is power, left pin is power.

From your readings it is sounding like all your lines are good and it looks like your sensor thinks its running pure alcohol.

Hate to say it, but you just might need the sensor. If you get a scanner that can pull PIDs tomorrow post up here and I'll put up the scan tool parts of the test. Some of them you may need a Ford IDS for though. The first one is a bit mapped fault PID, and I think you either need IDS or the highest end Snappy unit to pull those up.

 

[pjtoledo]

pulled codes P0176, fuel enhancement error, and P0401 insuffifient EGR flow. The Egr one has been there for years, I'm not too worried about P0401.
When I try to start it at WOT black smoke puffs out the exhaust with some backfiring. Running real rich, so everything points to the FF sensor saying it has mostly pure alcohol in it. The actual contents of the tank should be plain 'ol 87. We started with 1/3 tank, then topped it off and immediately drove 30 miles at freeway speed, ran smooth then WAM! instant bucking. Within 3 miles it was dead on the side of the road. Since it had sucked down at least 2 gallons trouble free after the fill-up, I'm doubting fuel is part of the problem.
I ordered a FF sensor replicator today, it outputs a fixed gas-only signal. That should get it back on the road. If not, I might be forced to buy the wiffie a new truck.

Perry

 

[adsm08]

that should fix your problem.

 

[WJC97]

Yeah, it sucks, I steer people away from any Ford FlexFuel vehicle. Nothing but trouble with those crap modules on both the Taurus and Ranger. The whole FF idea was stupid to start with, in hindsight.

 

[Hopman]

Actually, the who "corn ethenol" idea was crazy to start with, given for the ammount of ethenol produces, it takes nearly that much to refine it from corn.

Now if only we could get more "clean deisels" in the USA...

 

[adsm08]

Actually, the who "corn ethenol" idea was crazy to start with, given for the ammount of ethenol produces, it takes nearly that much to refine it from corn.

Now if only we could get more "clean deisels" in the USA...

While that post was poorly written I think I know what you meant. Anyway...

With the exception of pure sugar CANE ethanol all of the "Flex Fuel" mixes are net producers of carbon since a certain amount it produced in the refinement of the alcohol, and then for each gallon of alcohol you have approx. half the energy of a gallon of straight gas.

As an example, the air/fuel ratio for optimum burn (stoichiometric) on straight gasoline is 14.7 lbs of air to 1lb of fuel.

E85 on the other hand has a stoich ratio of 9.8:1.

So not only does it produce more carbon to refine, you have to use just less than twice the fuel to go the same distance at the same speed.

Hybrids are also a joke. With the exception of a car that does purely city driving, over the course of the car's life it will get worse mileage that a non-hybrid model (Fusion hybrid vs. 2.3L auto Fusion) with the average driver. On the highway the hybrid drive just creates more weight that a small engine has to haul around and provides an insignificant assist to the engine at highway speeds.

+1 for the clean diesels tho. Turbo Direct Inject is the way to go.

 

[Original_Ranger84]

Where did you get this so called sensor replicator? and for how much? I have a 99 3.0L FFV with 95K and don't really wanna have to go through this... if it ever happens... then agina I might just swap over to a 5.0 or 4.0L if I can...

 

[pjtoledo]

tandselectronics.com


$150 +$12 s&h

it arrived today, I'll install it as soon as I get enough ambition to lay in the snow under the truck.

 

[pjtoledo]

While that post was poorly written I think I know what you meant. Anyway...

With the exception of pure sugar CANE ethanol all of the "Flex Fuel" mixes are net producers of carbon since a certain amount it produced in the refinement of the alcohol, and then for each gallon of alcohol you have approx. half the energy of a gallon of straight gas.

As an example, the air/fuel ratio for optimum burn (stoichiometric) on straight gasoline is 14.7 lbs of air to 1lb of fuel.

E85 on the other hand has a stoich ratio of 9.8:1.

So not only does it produce more carbon to refine, you have to use just less than twice the fuel to go the same distance at the same speed.

Hybrids are also a joke. With the exception of a car that does purely city driving, over the course of the car's life it will get worse mileage that a non-hybrid model (Fusion hybrid vs. 2.3L auto Fusion) with the average driver. On the highway the hybrid drive just creates more weight that a small engine has to haul around and provides an insignificant assist to the engine at highway speeds.

+1 for the clean diesels tho. Turbo Direct Inject is the way to go.

The new ECOBoost engines may give TDI a run for their money. A big advantage diesels had was no fuel wasted during cylinder scavenging. Gas direct injection engines don't spray fuel during scavenging either. The 365 hp from a 3.5L V6 in the new Taurus SHO is quite respectable.

Perry

 

[triumphrider-1]

While that post was poorly written I think I know what you meant. Anyway...

With the exception of pure sugar CANE ethanol all of the "Flex Fuel" mixes are net producers of carbon since a certain amount it produced in the refinement of the alcohol, and then for each gallon of alcohol you have approx. half the energy of a gallon of straight gas.

As an example, the air/fuel ratio for optimum burn (stoichiometric) on straight gasoline is 14.7 lbs of air to 1lb of fuel.

E85 on the other hand has a stoich ratio of 9.8:1.

So not only does it produce more carbon to refine, you have to use just less than twice the fuel to go the same distance at the same speed.

Hybrids are also a joke. With the exception of a car that does purely city driving, over the course of the car's life it will get worse mileage that a non-hybrid model (Fusion hybrid vs. 2.3L auto Fusion) with the average driver. On the highway the hybrid drive just creates more weight that a small engine has to haul around and provides an insignificant assist to the engine at highway speeds.

+1 for the clean diesels tho. Turbo Direct Inject is the way to go.

Whats your source?

The LHV is not half of gasoline, neither is the HHV.

Ethanol has a lower stoich value because it has oxygen already in the moelcule chains, so needs less of it in a given volume.

Fuel economy drops anywhere from 10%-30%, depending on the vehicle. Mine for example is right around 10%. Emissions are also reduced in vehicles running ethanol somewhere between 10%-20%.

Clean diesels are nice, but cost a bit more. I can see a lot more vehicles coming with DI, and hopefully will see more with automatic manuals (something like the Volkswagon DSG system).

Appologizes for thread jacking.

 

[Will]

Not having to compress the fuel is another biggie.

I think diesel fuel takes less energy to make since it lower on the distilling tower and that compression ignition is still more efficient. The Mazda Speed3 is DI turbo and has been around a while and gets shit for gas mileage. We're not going to see 45mpg out of DI gasoline like you will with a Jetta TDI. The Speed3 is obviously a hotrod, but a hotrod Jetta would still get 45mpg.

 

[adsm08]

Yes the ecoBoost is a great engine. I think they probably will give TDI diesels a run for their money. As for Ethanol have a lower stoich, that's wrong.

9.8 pounds of air to 1 lbs of fuel is a higher ratio than 14.7 lbs of air to 1 lbs of fuel. My numbers come right from Fords own Flex Fuel training course materials.

The actual use of ethanol as fuel does have lower carbon emissions than straight gas, but the production of the ethanol from anything other than pure sugar cane makes more carbon than its use saves.

Are you sure you are getting E-85? Our FF s-10 drops almost 40% on E-85.