Trouble with reading codes

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Nov 17, 2004 | 03:43 PM

#31

EPNCSU2006

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From: Concord, NC

ECT looks fine to me - 6 = 6000 ohms and 60 = 60000 ohms if you were on the 1000 ohm scale. The ECT doesn't usually go bad either. 5 Volts sounds correct too. Are you checking the codes with the engine fully warmed up?

Nov 17, 2004 | 04:31 PM

#32

mike L

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From: va

codes

Quote:

Originally Posted by EPNCSU2006

Yes engine it was hot ( ran for 30 minutes)when doing the codes with engine running. Does it matter if hot when doing the codes with the engine off? Which codes do I check it first.

CODE 31 EVP my sensor is on the bottom of the egr on my 4.9.
EVR signal is/was low ? not list for my truck
PFE signal is/was low ? not listed for my truck

CODE 12 ISC Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) on mine i think its a Air Control Tept. sensor.

CODE 41 RUNNING Lean

CODE 33 EGR is not listed for codes while running??? egr not opening also EVP not working?

CODE 13 ISC (R) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high)

What is the ISC, EVR and PFE on mine? I can't find these in the manual for my 4.9 liter truck. When my old eec had 6 volts on the sig rtn/ ground ( black- white strip) wire would that burn out some of my sensors?

Last edited by mike L; Nov 17, 2004 at 05:17 PM.

Nov 17, 2004 | 10:33 PM

#33

EPNCSU2006

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From: Concord, NC

If the engine is cold when you do the engine off test, the computer will usually set a code for coolant temp sensor and air temp sensor being out of self test range.

EVR is the solonoid that controls vacuum to the EGR valve. The EVP is the sensor mounted on the EGR valve itself. The code is saying that the computer isn't sensing the EGR valve opening - there is no PFE sensor on your truck. Don't worry about this code until you get the truck running.

The idle speed code is due to some issue with the air bypass valve (ISC/IAC/etc. it has many names, still does the same thing) mounted on the throttle body. Clean it out really well and stick it back on. It could also be that you didn't goose the throttle during the engine running test.

I think as soon as you find what is causing all the fuel to get dumped in the engine, it might run.

Nov 19, 2004 | 08:54 PM

#34

mike L

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From: va

repaired

Brought my truck to Fords for repairs. Front fuel pump is bad. Map was bad. IAC had a bad gasket, vacuum leak. Only trouble code Ford got were bad map sensor. IAC gasket caused it to run lean and may of cause the Map to burn out. Then the Map was causing it to run rich. Wouldn't start because it got flooded. Why did I get all these codes then???? Thanks for all your help. You guys help me figure out how to read a wiring diagram. Learn how to read a DCvolt meter to test my engine sensors. How to get trouble codes. Thanks again
Mike

Nov 19, 2004 | 10:42 PM

#35

EPNCSU2006

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From: Concord, NC

I'm glad you finally got it going again! I know how frustrating it can be to not have the thing work like it should.

Nov 20, 2004 | 07:26 PM

#36

mike L

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From: va

My front intank fuel pump did not hold fuel pressure at the shop. the rear tank held pressure. I drove home on the front tank any ideas why my front intank fuel pump would drop pressure but I can still use it. Does the fuel pressure bleed out while its parked?

Nov 20, 2004 | 07:41 PM

#37

fefarms

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Fuel pressure is tested at the rail by running the fuel pump and checking for the correct PSI. Then the fuel pump is turned off and one watches for bleed-down.

So when you say "the front pump did not hold pressure", the question is whether the PSI was too low, or whether the pressure was OK, but bled down too quickly when the pump was turned off. It could be either; the way the statement is worded.

If the pressure is OK, yet it bleeds down too quickly when the pump is turned off, it is likely the pump has a bad check valve. The engine will run OK, but may take extended cranking to start due to the lack of residual pressure in the rail. You may also get crossflow from the rear tank to the front tank.

If the pressure is too low, the engine will tend to run lean. The PCM may be able to compensate by observing the lean running on the oxygen sensor and increasing the injector pulse width. Fuel delivery is proportional to the square root of fuel pressure, so a static pressure which is (say) only half of what it should be is still probably within the range of the PCM to make corrections, at least under light load. Full throttle operation and cold start would be a different story.

Nov 21, 2004 | 01:33 PM

#38

mike L

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From: va

low pressure fuel pump

All Ford was it went to 20 psi and dropped down to zero real fast. On cold starts it starts right up. I did not try it under heavy loads. Is it ok to run the tank to 1/4 tank, then I can change the in tank fuel pump. Do I have to change both low pressure pumps, what happens if i just change one. Does it make the new pump wear out faster? My rear pump is orginal and runs ok but the tank leaks a little. Thanks again