Computer swap issue...Fuel pump stays running
 

Previous Post on computer swap:

https://www.ford-trucks.com/forums/1...2-f-150-a.html

Well I received the used 5.8L Computer today for my 5.0 to 5.8L swap. I decided to go ahead and hook it up to test it on my 5.0L that is currently in the truck just to see if it works..

Here is the issue.

When I turn the key on, "engine off." The Fuel pump stays running and does not shut off. IT just stays priming the pump. That whining noise you here for a short moment... It just stays going... Is that normal? I don't think it is...

It cranks and runs the 5.0L engine, "but the check engine light comes on about 2 seconds after start."

I removed the 5.8L computer and reinstalled the 5.0 computer to make sure it was not another issue...The fuel pump turns off after a moment and the check engine light is not on when running...So....

I just wanted to ask you guys to see what you all think. Thanks

Bad computer :-X19

That is what I figured.... Thanks

Sorry dude. :-(

The ebay seller responded.

"It might need flashed by a dealer programmed to your truck"

I'm thinking it needs to go in one of my junk pile plastic tubs and order a mass air conversion kit.

There is no flashing on this vintage truck. You bought a door stop. Get your money back.

The seller is now asking if it is the exact same number as my old one. The only issue I should of had was the Fuel consumption being greater do to the 5.8L fuel curve.... That was what I was hoping for

He or she sold you a junk yard PCM, has no clue if it even worked right, and doesn't know 1 THING about the item they are selling!

As RLA pointed out, there is NO flashing needed on this vintage PCM and its NOT a Chevrolet/GM PCM!

Tell him your PCM works fine and you bought this one as a spare. The seller doesn't need to know what your Catch Code for the PCM is. When they state, "It may need to be flashed by the dealer" they don't know diddly about these PCMs we are dealing with. Demand your money back! Open a complaint file immediately! Get the ball rolling.

Let us know who the seller is. I'm curious and want to see his or her feedback.

If they we want your Catch Code for the PCM, then just tell them its the exact same as the one I bought!

He said he will send me another one if I send the other one back...I'll have to ask him whats the number on it to make sure its not one for a AoD...That would be my luck...

I went to the Local Ford Dealer and talked to one of the techs....He said that some of those older style OBD1 computers had a continuous loop circuit for the fuel pump for heavy duty use similar to the 460 big blocks. After a few minutes of talking and explaining that it does not shut off with KOEO at all.

He then said, "Although it should shut it self off after about 30 seconds." The only way to know if it is bad is to test it.

I tried again to see if it would shut off and the fuel pump continued to run with KOEO...

I went ahead and sent the computer back...

The seller is sending me another one...The seller said, "I know for a fact this is a good computer I am sending you." He has been pretty cool about the issue I am having with it.

Never heard of that before. Personally I think that mechanic is full of BS.

Seller Sent same model EOD computer to replace the one that was broke...It works perfect. Fuel pump shuts off after a second and no check engine light even when testing it on a 5.0L just to see if it works.

It was a bad computer

Glad to see the issue was resolved.

FYI.
You may want to check the capacitors in that PCM before trusting it indefinitely. I would check the 5.0l PCM too. And while your not using it, just get those capacitors replaced. It'll be worth its weight in gold, if this 5.8l PCM starts giving you problems and then turns your project into a boat anchor.