http://fordfuelinjection.com/files/H...trol_works.pdf

"What about Open Loop?" you might ask. Well, it works there too. This
fact alone is know by very few people. Most people think Adaptive only works
when in Closed Loop. This is wrong! Adaptive is only UPDATED during Closed
Loop. It would be silly to ignore changes in the air and fuel system in Open Loop
and only correct them in Closed Loop. If you have a serious fuel problem, your
car might not even start if the EEC didn't have some way of correcting things all
the time. The way the EEC uses Adaptive in Open Loop is similar to Closed Loop
except it doesn't update the table. This means it's not looking at the oxygen
sensor for feedback. It is merely relying on the information stored in the table to
make corrections. Since the Adaptive table only contains Speed / Load points
normally seen during Closed Loop, where does the correction factor come from if
I'm at WOT? Good question. The answer is; it uses the last value it was using
while in Closed Loop. Since the Keep Alive Memory has power to it even when
the ignition key is turned off, the Adaptive table retains it's information. The only way to clear the Adaptive table is by disconnecting the vehicle's battery. Do that
and you're back to working with a clean slate and the whole process starts over
again. Now there are limits to how much the Adaptive Control system can
change the calibrations. The adaptive system has a range of roughly +/- 25%. If
you had an adjustable fuel pressure regulator installed, and you needed more
fuel, you could keep cranking it up until the EEC could no longer dial the fuel
back out. The problem with this is you will set a code and the 'Check Engine' light
might come on.
A quick tip. When setting your fuel pressure, always check it with the
vacuum reference DISCONNECTED! The pressure reading with the vacuum
connected to the regulator depends on how much vacuum your engine pulls at
idle. Depending on your camshaft, this can vary quite a bit. If you have a big cam
and set your idle pressure to 32 PSI with the vacuum reference connected, you
might only be getting 36 PSI at WOT. It's VERY important to set the idle pressure
with the vacuum reference disconnected. This way you know for sure how much
fuel pressure you get at WOT.

 

Well... It is true, but EEC-IV has no fuel pressure sensor. But in case of different problems related with fuel pressure it ios difficult to understand what is going on. I installed fuel pressure sensor and fuel pressure gauge inside the cabine and I see, it what regimes fuel pressure is out of norma.

Well, my advice, use oil pressure sensor with special selfmade adapter, installed on fuel pressure port. To get well looking gauge if easy too, any car tuning shop offer it.

 

Thanks 96_4wdr. Again, you are a wealth of information.

After some pondering, I'm wondering what failure among the many inputs sends the EEC into the 'limp-home' mode? It would seem there would always be a previous, fall-back datum point to use if one or two inputs were way out of line.

Pablo, if I ever enter my Aerostar in the Paris to Dakar rally, I'm taking you along as chief mechanic. You never cease to amaze me with your mechanical talent.

 

To win Paris-Dakkar, use KAMAZ with 1000 HP engine, ZF Tranny, WABCO air electronic brake system, Webasto climat unit and 2 crazy drivers, who can drive 10 ton truck at 80 MPH on sand...... Put aero inside this KAMAZ and enjoy!

 

Pablo,
were do we put the bed-sofa, the Aero wine and the women?

probably the MAF or MAP on older systems is the major one, PCM has no input on air intake other than approx. by TPS and rpm...the PCM algorithms are so adapative to failures by using software to simulate hardware sensors that it's hard to drive an OBD system into Limp Home, especially the EEC-V

the newer systems will not even allow engine or tranny overtemp operation for long without starting to severely restrict operation and put us into a modified Limp Home, no tc lockup or OD, rpm limited to 2500 rpm, engine load limited to lower value

 

Todai is 25 dgr F today, really cold, my Ranger did not start, starter cranks the engine, but it idid not fire.... New Platinum Spark Plugs..... Yesterday Aero did not want to start, becouse the battery was low and we pushed her and start on 2nd gear.... Today aero started well. So I dont understand why 4.0 SOHC does not start when it is cold?????

 

you must mean -25d F aka -32d C ??

same fuel, out of same delivery load?
same oil viscosity? 0w30?
go to a 0w20 for winter time light load driving
the 4L SOHC does have higher crank loads because of all that spinning flapping cam shafts and long chains

our fuel here in the Pacific NW is the worst I've seen in years. Tons of benzene, the EPA let the oil gas companies off the hook here because of higher benzene levels in Alaskan oil and high import oil costs.
first winter my Aero has ever been hard starting and we've hardly been below +32d F 0d C. engine catches and dies, not it's normal fire off on 2 second crank...
fuel mileage dropped on all our rigs 10%>20%
all is at least a 10% ethanol summer and winter mix now that MTBE is EPA forced out of gas as octane add.
the garbage has no power

 

It is unusually cold here..... It was +12 dgr C last week, but this night is -20 dgr C!!!!! Oh my god!

The problem with ranger is, that starter crancks the engine well, wery well!!!!! But! No fire!!!! NO! and NO DTC CODES! Aero with old battery and not the best starter starts.... After the first turn of crankshaft.... If stareter does not crank the engine, It is enought to push it and use 2nd gear! That is all!

What a hell is going on with 4.0 SOHC????? I wanted to check for signals on Cranckshaft pos. sensor, camshaft pos. sensor, spark and signal on injectors, but it is so cold!!!!!!! Oh my GOD! so I had to haul big coutretops inside my aero with open tailgate! Having ranger!!!!! with new platinum spark plugs!

 

fuel pressure regulator problem?? ....pressure should be the highest at cold start

or failed IAT sensor...failed at higher temp above 0d C?

 

Try to start with pressed to 5-10% gas pedal... what a difference?