Erratic Idle and bucking

[TheWeldingFords]

I can now say the entire fuel system is new since March, I can't check fuel pressure anymore because my gauge crapped out and doesn't like to read on the rail anymore.but when I was relieving pressure last night it definitely had a lot of pressure.

I can't afford a relocation kit for the tfi yet but I'm gonna get one later, I'll carry a spare one on the road trip along with extra belts and a starter solenoid since I haven't used the pmgr starter to it's fullest yet.

Anything else I should probably carry extra on?

[TheWeldingFords]

Just put new tfi module in and timed it and still has the same problems.

Could it possibly be a MAP sensor, what else would change during idle and when using throttle?

[TheWeldingFords]

I'm getting KOEO codes of

32: EVP circuit below minimum voltage of .24 volts

67: neutral safety switch open(I have it jumped because the arm of it broke)

95: Fuel pump secondary circuit failure. The EEC senses infinite resistance to ground from the fuel pump on the fuel pump monitor circuit



Continuous memory of

22: MAP sensor out of test range

29: Insufficient input from vehicle speed sensor

33: EGR valve opening not detected

41: No HEGO switching detected always rich

54: ACT sensor signal is greater than self test maximum of 4.6 volts

What should I start with first based off this?

[Gary Lewis]

Have you done a KOER test?  I would think that would be important, but I'm not up to speed with the EEC-IV testing.

However, I don't see #32 as EVP.  Our page at Documentation/Electrical/Electronic Engine Control (EEC) has 32 as "EGR valve not seated; closed voltage low".  And you are seeing a 33 in memory that I agree is EGR.  And the EGR valve can certainly give an erratic idle if it isn't closing properly, which happens when it gets carboned up.

[81-F150-Explorer]

Start with the KOEO codes first:

As Gary states: Code 32 =

Code 32: EGR Valve Not Seated: Closed Voltage Low;  Could cause a lean condition

Code 95: Fuel Pump Circuit open PCM to motor: The Wiring is faulty or the Fuel pump could be weak. Could cause a lean condition.

----------------------------------------

Continuous memory:

Code 22: MAP sensor could be faulty and/or wiring.

Code 29: Vehicle speed sensor could be faulty and/or wiring.

Code 33: EGR Valve opening not detected.  Could be stuck open. See Code 32:  Can cause a lean condition.

Code 41: Fuel System always LEAN or Fuel System Always Lean Bank 2 or O2 Sensor malfunction.

Code 54: Intake Air Temp sensor open: Wiring or sensor fault.

----------------------------------------------

Code 32; 33;  and 95 can all be related to make a fuel system run really lean.  

Since you replaced the injectors and cylinder five is farthest from the Fuel Pump...

First check the EGR valve. It could be stuck open. As Gary suggests.

Second I'd check the Fuel Pump and related wiring.

Then go on from there to the Continuous memory if things do not change.

[TheWeldingFords]

Would the 95 code be for the intake pumps or is it the high pressure pump on the frame?

I changed out the map sensor earlier and no change I'm not sure about the map code from earlier because I just cleared it and haven't tested the continuous memory yet

[Gary Lewis]

The 95 code is for all the pumps.  In the schematic below the power comes in to the fuel pump cutoff relay on ZZ and YY goes to the ECU.  And if the ECU doesn't see the relay it'll throw the code.  And that relay powers all of the pumps.

I'm still thinking it is the EGR valve.

[TheWeldingFords]

Okay I opened up the EGR valve at the top and cleaned it up with some brake clean and moved it up and down to verify it wasn't stuck, I also ran codes again while the sensor was out of the valve to verify it does change what code it throws when its out of range on the low side. After all that I re installed it and verified voltage going to it and also ohmed the sensor and tested it with vacuum and heard it move and the ohms dropped down like it was supposed to.

Should I replace the whole EGR and sensor or just the sensor? I am on a very tight budget so money is a factor because I already have to survive off ramen for the week.

Could the reason for the fuel codes be because I converted both the EEC and Fuel pump relays over to the bosch style relay instead of the ford relays?

[81-F150-Explorer]

TheWeldingFords wrote

Okay I opened up the EGR valve at the top and cleaned it up with some brake clean and moved it up and down to verify it wasn't stuck, I also ran codes again while the sensor was out of the valve to verify it does change what code it throws when its out of range on the low side. After all that I re installed it and verified voltage going to it and also ohmed the sensor and tested it with vacuum and heard it move and the ohms dropped down like it was supposed to.

Should I replace the whole EGR and sensor or just the sensor? I am on a very tight budget so money is a factor because I already have to survive off ramen for the week.

Have you ran the truck after cleaning the EGR valve?  That may have done the trick. so to speak.

Could the reason for the fuel codes be because I converted both the EEC and Fuel pump relays over to the bosch style relay instead of the ford relays?

Are the Bosch relays of the same values as the Ford ones?  If they're not then it might fool the EEC perhaps.

Also check the wiring if you modified anything. Did you leave anything disconnected?

The EGR valve if it's being held or stuck open will cause a  leak between the exhaust and the intake, which can cause a lean condition.  Which could give you a code 41.

The 95 code could be caused by a bad ground among other things. Gary's diagram will help you trace wiring faults if you have them.

[TheWeldingFords]

Okay I replaced the egr sensor and it got rid of that code, but now when floored it bogs down like it's getting way too much air but it did fix the jumping idle I believe, it did have a bit of lack of power could barely use second to move.

Relays look like they are the same specs between the Ford and the Bosch style.

Just left with code 95 because the 67 one is unimportant.

How crucial is the engine to firewall ground?

[TheWeldingFords]

Well I just pulled out the ground strap and it may have been the problem just looking at it

[Gary Lewis]

The engine/firewall ground strap is crucial. In Bullnose trucks it is the only way the cab gets grounded. In later years Ford added several more grounds because of all the problems when that ground failed.

[81-F150-Explorer]

Gary Lewis wrote

The engine/firewall ground strap is crucial. In Bullnose trucks it is the only way the cab gets grounded. In later years Ford added several more grounds because of all the problems when that ground failed.

Ditto!

[TheWeldingFords]

well I made a new ground cable with some 2 gauge, still throwing code 95.

I'm gonna try a different fuel pressure gauge tomorrow because so far its sounding like it might be a fuel issue because of the stumbling over itself when going over 2500-3000 and it lacks a bit of power.

[ArdWrknTrk]

If you made a new ground cable, how is the pigtailed ECM (injector) ground that comes from the battery ground terminal to the radiator support where it connects to the computer's harness?

[AmericanSavage]

I had some electrical pulsating problems a long while ago. The ground strap looked "OK” but I replaced it anyway—cured ALL my problems.  Crucial piece!

[TheWeldingFords]

ArdWrknTrk wrote

If you made a new ground cable, how is the pigtailed ECM (injector) ground that comes from the battery ground terminal to the radiator support where it connects to the computer's harness?

I'm not seeing a harness that connects from ground to the radiator support, I only see the ground from the battery connect to block and then the block to the firewall.

I rented a different fuel gauge and the highest pressure it would read was 30 psi because it kept leaking at the adapter and that was with the pump constantly running

[81-F150-Explorer]

I'm leaning toward more wiring faults somewhere, and/or weak windings or grounds to the fuel pump or pumps.

First I'd check the wiring going to the EEC from the fuel pump cutoff relay. Wires ZZ and YY in Gary's schematic.  

There should also be a connection through the fuel pump cutoff relay between wires ZZ, YY and the inertia switch wire 787 pink/black, or 37 Yellow wire when the cutoff relay is closed.

Make sure these wires are working correctly, or fix the problems, and work forward from there if needed.

[TheWeldingFords]

Also I forgot to mention that when I first started it up cold it ran great no weird idle and plenty of power throughout the rpm range no bucking but then a minute later when it made it out of the cold temp into the beginning of normal temp it started it again.

The distributor is a bit hot but the coil  is only a tad above room temp

[TheWeldingFords]

I checked for codes again

KOEO
---------------------
67: not a problem, jumped the NSS
95: Fuel pump circuit open, PCM to motor


Continuous memory
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29: no Input from vehicle speed sensor
33: EGR valve not opening, insufficient flow detected
95: same thing as KOEO code


Based off this from my last drive because I cleared codes before I did it, once engine gets to beginning of normal temps it begins having problems, so something is getting warm and messing something else up

Where should I check next for getting rid of code 95, how would I test it?