running rich

[muddacres]

90 ranger 4.0. It is running rich at all rpm ranges. I have changed all these, Canister Purge Valve Solenoid, Oxygen Sensor, Air Charge Temperature Sensor, Air Cleaner Temperature Sensor, Coolant Temperature Sensor, Crankshaft Position Sensor, Idle Air Control Valve, Mass Air Flow Sensor, Throttle Position Sensor and Fuel Pump. If I pull the power brake vacuum hose off it runs great. The temp runs about normal. Any ideas.
Jim

 

[black_demon69]

90 ranger 4.0. It is running rich at all rpm ranges. I have changed all these, Canister Purge Valve Solenoid, Oxygen Sensor, Air Charge Temperature Sensor, Air Cleaner Temperature Sensor, Coolant Temperature Sensor, Crankshaft Position Sensor, Idle Air Control Valve, Mass Air Flow Sensor, Throttle Position Sensor and Fuel Pump. If I pull the power brake vacuum hose off it runs great. The temp runs about normal. Any ideas.
Jim

try plugs wires and possible coil pak for starters

 

[muddacres]

Sorry, when I first got the truck, new plugs, wires, thermostat, intake gaskets, valve cover gaskets and water pump. I just changed the clutch fan and changed the coil pack from my explorer. I tried to drive it and it must have been getting 5 mpg.
Jim

 

[adsm08]

Did you check the fuel pressure regulator?

 

[muddacres]

I tried but the gauge I borrowed didn't fit. I'm going to see if autozone has one to borrow.
Jim

 

[stuntsunltd.]

+1 for the fuel pressure regulator

 

[muddacres]

I changed out the regulator pulled the injectors and cleaned them. Put it all back together it run fine for 5 or so min and right back where it was. Does anybody think that the ECM relay might have anything to do with this?

 

[RonD]

90 ranger 4.0. It is running rich at all rpm ranges. I have changed all these, Canister Purge Valve Solenoid, Oxygen Sensor, Air Charge Temperature Sensor, Air Cleaner Temperature Sensor, Coolant Temperature Sensor, Crankshaft Position Sensor, Idle Air Control Valve, Mass Air Flow Sensor, Throttle Position Sensor and Fuel Pump. If I pull the power brake vacuum hose off it runs great. The temp runs about normal. Any ideas.
Jim

No, on EEC(ECM) relay

And stop replacing sensors and controls, Sensors rarely fail, but they are often changed

Running rich means you are blowing black or grey smoke out the exhaust, correct?

And when you add more air to the mix(pull vacuum line) you get a better mix?

Vacuum line on Fuel Pressure Regulator(FPR) should be checked, FPR can leak(even new) and extra fuel will be sucked into intake via that vacuum line, so pull it off and check it for fuel.

Next after engine is warmed up shut it off(key off) and pull off air intake at throttle body(upper intake), listen for dripping and smell for gas fumes, there should be none since injectors are closed.
If you smell gas or hear dripping you have a leaking injector.
Like most things injectors can be tested with a volt/ohm meter, one of these $15 meters can save you hundreds of dollars.

If you don't smell gas, turn on key, but do not start.
Now smell for gas again, there should be no smell.

Those are the mechanical things that can cause rich mix.

MAF sensor is the main fuel/air sensor
Again it should be tested with volt/ohm meter, look here for how to test:
http://therangerstation.com/tech_library/CleanMAF.html

New no longer means "it works", new now means "never tested".

If MAF power voltage is good and its return voltage is good then computer is bad.
ioes Check Engine Light(CEL) come on with key and then go off?
Unplug MAF sensor and start engine, CEL should come on.

O2 sensors, air temp sensors, and pretty much all the other sensors couldn't cause the "5mpg" you mentioned, these are just fine tuning sensors, you might go from 15mpg to 12mpg but nothing like 5mpg, thats almost a fuel line leak MPG, lol.
Throttle Position Sensor(TPS) might if it was telling computer your foot was always on the gas pedal, but TPS is easy to test, its the same as a light dimmer or volume control, voltage goes up as foot presses down.


EDIT:
Thought of something else you can try.
On fuel injected engines the computer has a "flooded engine" routine.
If you turn the key on, then press gas pedal to the floor, the TPS sends computer WOT(wide open throttle) voltage.
This tells computer to start "flooded engine" routine, computer will not turn on injectors during cranking but will still send spark to plugs.

With foot still holding gas pedal to the floor, crank the engine, it should not start or even fire, if it does then you have leaking injectors or another fuel leak into the manifold.

 

[muddacres]

No, on EEC(ECM) relay

And stop replacing sensors and controls, Sensors rarely fail, but they are often changed

Running rich means you are blowing black or grey smoke out the exhaust, correct?

And when you add more air to the mix(pull vacuum line) you get a better mix?

Vacuum line on Fuel Pressure Regulator(FPR) should be checked, FPR can leak(even new) and extra fuel will be sucked into intake via that vacuum line, so pull it off and check it for fuel.

Next after engine is warmed up shut it off(key off) and pull off air intake at throttle body(upper intake), listen for dripping and smell for gas fumes, there should be none since injectors are closed.
If you smell gas or hear dripping you have a leaking injector.
Like most things injectors can be tested with a volt/ohm meter, one of these $15 meters can save you hundreds of dollars.

If you don't smell gas, turn on key, but do not start.
Now smell for gas again, there should be no smell.

Those are the mechanical things that can cause rich mix.

MAF sensor is the main fuel/air sensor
Again it should be tested with volt/ohm meter, look here for how to test:
http://therangerstation.com/tech_library/CleanMAF.html

New no longer means "it works", new now means "never tested".

If MAF power voltage is good and its return voltage is good then computer is bad.
ioes Check Engine Light(CEL) come on with key and then go off?
Unplug MAF sensor and start engine, CEL should come on.

O2 sensors, air temp sensors, and pretty much all the other sensors couldn't cause the "5mpg" you mentioned, these are just fine tuning sensors, you might go from 15mpg to 12mpg but nothing like 5mpg, thats almost a fuel line leak MPG, lol.
Throttle Position Sensor(TPS) might if it was telling computer your foot was always on the gas pedal, but TPS is easy to test, its the same as a light dimmer or volume control, voltage goes up as foot presses down.


EDIT:
Thought of something else you can try.
On fuel injected engines the computer has a "flooded engine" routine.
If you turn the key on, then press gas pedal to the floor, the TPS sends computer WOT(wide open throttle) voltage.
This tells computer to start "flooded engine" routine, computer will not turn on injectors during cranking but will still send spark to plugs.

With foot still holding gas pedal to the floor, crank the engine, it should not start or even fire, if it does then you have leaking injectors or another fuel leak into the manifold.

I tried the gas pedal thing and it didn't start. I got a volt meter today to check it out.

 

[muddacres]

With the engine running at idle, use a DVOM to verify there is at least 10.5 volts between terminals A and B of the MAF sensor connector. This indicates the power input to the sensor is correct. Then, measure the voltage between MAF sensor connector terminals C and D. If the reading is approximately 0.34-1.96 volts, the sensor is functioning properly

I checked the voltage and it was 14.75 and the other was 1.7. It don't mater if I unplug it, It stills runs like crap.Jim

 

[RonD]

14.75v should be OK if engine was just started, idle would be high and Voltage regulator would be outputting +2volts over battery voltage to recharge battery after using starter motor.
1.7v is within parameters

There are 2 Coolant temp sensors, well, one sensor, one sender.
The 1 wire sender is for the dash board gauge
The 2 wire sensor is for the computer

Since you have a meter now set it to 20vDC, turn on the key, engine off, remove connector on 2 wire sensor and test wire for 5vDC, only one wire will have 5vDC, the other is the "return" wire.
If voltage is OK, change meter to OHMs and test the two contacts on the sensor, cold engine should have high OHMs, start engine and warm it up, OHMs should start dropping, if not replace sensor.
ECT sensors rarely fail, but if they do fail with high OHMs then engine will run rich all the time.

All you have left is the Fuel Pressure being too high, above 40psi.
Or the Computer itself running engine too rich, don't know of anyway to test computer.
You could hook up an ODB I reader and see if computer will communicate with it, if not then computer has issues.