So I ran the KOER test this morning. All I ended up getting was a code 25 ( no knocked detected). I didn't feel like testing this futher because reading on here. People seemed to say ignore it if there is no pinging noise. I was hoping I would get some sort of codes.

Than I decided to check out sensors with my volt meter. I checked the TPS it checked out. Than I checked the EGR position sensor, that one checked out ok. Than I checked the Idle air control valve, which checked out correct.
Than I was trying to figure out the timing. I have read about the SPOUT connector. You disconnect the SPOUT connector and than the timing reverts to 10*. I went down to remove the connector. I may have removed the wrong one. There is a 2 pin connector down near the ICM Plug, it has this grey plug in it(the wire was yellow with a green stripe). I removed the little plug. Went to start the truck and It wouldn't Start anymore!
Than I went to check the KOEO and it showed the code 96 Fuel pump secondary circuit failure battery - PCM. And sure as **** the fuel pump isn't turning on when the key is turned to run.
I went to check on the relays. One of the relays had water in it. I Vacuumed(dried) it out. It looked good after wards. I tried to run the fuel pump from the Diagnostics port. Connecting the 2nd pin with the 6th pin. The fuel pump would not come on. I could see a tiny bit of corrosion on the underside of the relay. Tried to remove the connector to look at it better. Than the wire came loose from the connector. It was the yellow wire going to the green relay.

In all honesty the Haynes manual i have is so difficult to read in regards to testing the EEC-|V. It Also doesn't have a good wiring diagram of the Fuel Pump circuit. I have a single tank.

I am a little lost. All I was trying to do was determine why it had a rough idle. I have started to replace Vacuum lines. Rockauto only sent me 6' when i had ordered 24' So those will be replaced soon.

I haven't been throwing money at it. What would you test? The haynes manual I have is not very good.
I have cleaned the IAC, Cleaned the Throttle body, new gasket for throttle body. Replaced the distributor rotor. New Fuel filter, coolant flush, oil change. Did my best to clean up all of the electrical connections.

 

Did you momentarily press the gas pedal to the floor during the KOER test? If so I wouldn’t worry about that code.

Did you remove a connector that looked like this?

 

yes that is the connector I removed. I also pressed the gas pedal. However i didn't goose it to 6000RPM.

I am going to spend some time working on the relay. I have power to it. With the fuel pump relay(the one that had water in it) plugged in the sixth plug on the self test plug only shows 5.40~V. I would assume it would show closer to 12volts. I am tempted to bypass the relay to see if the high pressure pump works.
I have a relay which looks like it fits the EEC power plug. It will not fit the fuel pump one without a little modification. Do not know the state of this relay.
I would really like to upgrade all of the wiring on this truck.

Does anyone know of an online source for diagnosing the EEC? Something with resistance numbers, voltages, wire sizes. I find the one column in the haynes manual really confusing and dense.

Last but not least I live remote and cannot go to the parts store easily. I will most likely order from Rock auto. Takes about a week to get here. I have a 1990 toyota truck which has a relay/fuse box on it. I could do that, however it will mess with the wiring diagrams..... wire colours and all. I would like to bypass these fuse able links.

Got to go. thanks for the help!

 

So i replaced the fuel pump relay with the one of unknown use. I needed to modify the relay for it to fit. Truck started. It is running super rich. No cold start like before, it used to raise to 1600rpm for a few seconds than drop down. Now it rocks between 600rpm-900rpm. Loping.

I did get the KOEO
51=ECT sensor signal is greater than the Self-Test maximum of 4.6 volts.
22=MAP/BP sensor out of self test range
53=TPS circuit above maximum 4.5 volts
54=ACT sensor signal is greater than the Self-Test maximum of 4.6 volts.
35=PFE or EVP circuit above the maximum limit of 4.81 volts
67=Neutral safety circuit failure

I am going to test each sensor. My plan is to unplug all of the sensors in circuit 46 sig ref. These all share a common wire. I will plug each one back in and see what the voltage at the 2nd plug on the Self test Plug. Hopefully it will drop...
I forgot to mention i have replaced the ECT sensor.




Also big news I now no longer have a 2g alternator! 95amps, it was putting out 40amps with this loping idle. I bought an alternator from a 96 4.9L Wiring was super simple. I needed to grind one bolt on the alternator bracket. It was in the way.

 

so, I started removing sensors connectors, I was reading the voltage at the self test plug, part of that circuit i mentions above. I would ground it to the ground near the radiator. The voltage kept increasing as i removed sensors. I wasn't really sure what that meant so i stopped doing that.

According to the haynes manual the VREF for these sensors is supposed to be around 5v. Well none of them were. I am not 100% sure i was testing it correctly. I removed the IAT sensor connector and the resistance of the connector was 0.2ohm. Manual said it should be 32.7ohms at 68*F. I supose it would be worth changing the IAT.

Another thing i noticed was the truck ran better with a vacuum line removed. It at least idled up. The truck ran really crappy cold. I suppose if the IAT sensor is telling me its very hot it would be trying to run without a cold start....

Yea i am going to take the ECM out. Its also running very rich. Its hard to be around the truck when its running.... Maybe I also should check the O2 sensor...

Anyways alot of weird issues which pop up after i replaced 3 vacuum lines. I will wait until i receive the remaining vacuum line before I rule that out.


Any suggestions anyone? I do not have a vacuum guage. I also do not have a fuel pressure guage. I have a new fuel filter which i might change out. I change the fuel filter 2 years ago. The old fuel filter came apart internally. You could shake it around and it would clunk!!!

 

From your resistance results the truck thinks it is very cold outside so it is adding fuel. That is the resistance when testing the sensor? You weren’t testing the wiring side of the plug, correct? The reason it ran better when you disconnected the vacuum hose is because you added more air to thin out the fuel ratio.

 

correct. I was testing the IAT sensor.

 

So i am getting fairly inconsistent results. I must have not had the probe on the IAT. It was showing good resistance this morning. Very likely as its a hard sensor to probe.
The voltage was low for Circuit 46.. I started taking sensors off on that circuit. When i removed the EGRP sensor. The voltage returned to within spec on the remaining sensors in that circuit.

Next i decided to check the ECM. Why not?. Well it turns out in between the pin 46 near the connector and the Capacitor, the wiring(wrong word probably) is broken. Probing it with my Fluke meter, i do not get any connectivity... I get connectivity where the wire has broken through.
Is this repairable?


Burnt 46 pin, also known as VREF

 

Also Do I need a different ECM? The part number is E8TF12A650Y2B. I cannot find this other than from ebay where it is 300 bucks US!

 

So i found an ECM from a 91 f150 with an AUTO 4.9. The Number SD20a was something like SD47. I pluged the board in. Truck started for about 5 seconds than stalled. It wouldn't restart after that. I did visually inspect the ECM before i installed it. This ecm wasn't easy to take apart. The one in my 89 used torx screws. this one looked like it was pressed together.
I do wonder if the different speed density numbers would affect it. I did get codes from the KOEO, however the engine was not warmed up...

I have a line on another ECM from one of these junkyards which take the part out for you, and than charge $$$$ The ecm takes about 5 minutes to remove!!!
anyways its 125$
Does anyone know if an ECM from a different code would work? They have one with E8TF-12A650-X2B for 95$.
I am almost tempted to ask for both of them.

 

So small update. After much deliberation I decided to buy the ECM from Cardone. I will probably open it up and inspect it before installing it. I can always buy the ECM from the junkyard and replace the capacitors, i doubt junkyard ecms are flying off the shelf for these trucks...

I also found a vacuum leak near the vacuum actuator(i don't know what its called) Its above the alternator. The vacuum hose had a crack in it. I replaced it with a new silicone line. I also found the coffee can had a large hole in it. It wasn't there until i tried cleaning it up with the wire wheel. I am going to patch it with chimney roof silicone and a hose clamp. I will keep my eye out for a better vacuum canister.

It will be about a week before the ecm shows up I suspect. Rockauto usually takes about a week to get here. I also ordered the fuel injector repair kit. So i will have that to work with when it comes.

 

So the ECM came. I plugged it in and it would not start. I went ahead and started diagnosing as it appears to be the same as before. I pulled #1 spark plug out and it was covered in fuel. The exhaust smells rich. I didn't check anymore spark plugs. Than I decided to check the ignition coil. Well the node was covered in corrosion. I took the ignition coil out and wire wheeled it clean. It tested within spec based on the Haynes manual. Than I decided to check the KOEO. I got code 22 and code 67.
22 is the map sensor out of self test range of 1.4v-1.6v and yes back probing it I get 3v~. VREF is 4.9VDC

So i unplugged the MAP sensor and truck still doesn't start. I can buy another one, it looks like testing it requires special tools.

Anyone have any suggestions? I can test the resistance of the spark plug wires. Any one have a good way of testing the TFI. I will need to study the haynes manual more...

 

found https://easyautodiagnostics.com/ford...module-tests-1 for testing the TFI

 

So doing this test has led me to believe the pip sensor is bad. I am getting no signal at all. Nothing showing up when cranking the engine. I used a test light to determine it wasn't working.

Reading on here has led me to believe it could be either the TFI or it could be the PIP sensor. Any suggestions? I feel quite lost when I consider taking the Distributor out. I have the haynes manual. Ill try to find a video.

 

Im looking forward to seeing your problem being fixed. The PIP sensor puts out a square wave that can be viewed on an oscilloscope. A normal multimeter can be used too with limited resolution. Connect the multimeter to the PIP wire, Pin 1 on the ICM or Pin 56 on the PCM, and the other multimeter probe to the positive battery post and crank the engine. You should see atleast 2-3 volts on a multimeter set to AC voltage.