So I used the truck last week. Moved a load of firewood. Truck moved it fine. I did notice when it started it would sort of think, before the IAC valve would come on and than the idle would shoot up to 1600rpm or whatever.

Went to start the truck and check on the battery voltage today as the truck has been sitting for about 2 months prior to moving the firewood.

The truck wouldn't start. Truck turns over. I noticed the fuel pump has been on the whole time. I than cleaned the battery connections just because. I than took the ecm out and it appeared normal. It was just replaced about 6 months ago. I didn't smell anything or notice and leaking fluids.

Than I went to run the Self test and It would not show me any codes on the dash. I turn the key to on and nothing happens with the code light. The code light is on.
SO I tried a few different methods. Tried different wires for the test. Tried grounding the second terminal to the sti terminal. Tried just grounding the sti terminal to the battery.

Nothing happening.

Came on here to see if anyone can guide me in a direction. I am wondering if the connection to the computer is suspect... I am not looking forward to opening that plug. There is also a possibility that it is a relay...

thanks in advance

 

So i just went to test the EEC relay. First test showed me that I am not getting voltage where I am supposed to be.

https://easyautodiagnostics.com/ford...-relay-tests-1

I tested the second pin and found I was only getting half a volt. 0.5VDC. Test said it should be getting 10.5VDC - 12VDC.

might be the Power (from ignition switch)....

 

Anytime the fuel pump starts to run all the time, after working normally, points to a bad computer.

It may be a recent replacement but another example of the poor QC the common "rebuilders" utilize these days.

Add in no code retrieval, points to a bad computer (PCM).

 

I think the most amusing thing to me is this truck has been used about 6 times since the ECM was replaced... I can start the process of returning it with rock auto.

I assume the pump runs the whole time because the computer leaves the injectors open?

 

could try unlugging the spout connector and see if it starts, it takes the ECM out.
Heres one that test ECM-->Fuel Injection Technical Library » No Codes?

 

No, the computer keeps the fuel pump relay energized because the internal clock is not working. Common failure mode.

As previously stated another example of the rebuilder not fully testing these PCMs, just colorful stickers on the outside and charging high prices.

Not a snub against you, the "rebuilder". Should be a class action against these offenders.

 

That is a helpful link. Ill try that out. If the pump was not running constantly I would try the spout connector.

 

I completely agree on the quality. They "repair" something. Sent it out to be sold. Give it a 1 year warranty. If the part last one year the end user is hooped.
Luckily It is still under warranty. The *******s will not even cover the return shipping for the replacement... I need to spend the money to return their failed part..

 

Does anyone know the part numbers for the Fuel pump relay, and the EEC relay? Rock auto has quite a few different relays listed....
I am hoping to have spares just incase one goes down later on.

 

dont buy the cheap crap, think stranded... part # --->Ford 5M5Z*14N089*A - Relay - 1990-2021 Ford | OEM Ford Part Online

 

Well, I found my spare computer. Plugged it in. Truck started up right away. No cranking over or waiting. Started right away. Didn't really idle right. Seemed to bog a bit when the throttle was let off.
I took the truck for a 20 minute spin and it performed well.

The spare computer is a Speed density 47. Its from a 91 auto 4.9L. It works but not well. I also do not know the condition of the truck the computer came out of. All I know is it had 426000KM on the odometer.

Ill have to keep looking for the correct motor craft relays. Even looking on that website you suggested didn't come up with anything.

 

You can go to any ford dealer and walk out with that part today, this # 5M5Z-14N089-A replaces this FOAZ-14N089-A

 

I believe that works for 92+ fords with ISO Relays. Mine is the old style relay currently. I am considering upgrading to the ISO relay very soon. I even have a bunch of tyco(bosch) relays from junkyards. I Just need a decent soldering iron. My current one is a 30w thing... Very slow with it.

 

So the replacement was received from rock auto. Truck works like normal so far... I have not driven it around, however it started and the fuel pump cut off after 2 seconds. the idle control worked. Now to see if it lasts