'99 5.0 in a '96 Ranger, PCM and fuel pump issues.

[540milotalon]

None of the above has been happening. I went back and verified the wiring, connections etc.
I will look over it all again and report back.

 

[540milotalon]

Rechecked all connections as good, all wiring as the downloaded PDF. There is continuity between all connections back to terminals on the ends.
I have to assume at this time either there is something wrong with key or PCM.

Is there some other step I missed like repinning at the 42/104 connector?

The donor vehicle started and ran before I purchased it, it suffered a right front collision that bent the frame and passenger floor board, deployed airbags but she started just by previous owner turning the key like she was supposed to.

 

[Mechrick]

Would it be easier to change a couple sensors and use the '96 PCM? Is that even possible?

You could swap in the cam synchronizer and sensor for the '96, but you are jumping ahead. The engine will run with the sensor unplugged. One bite (byte?) at a time.

Both the '99 and '96 PCM's control the fuel pump in the same manner. Since the '96 doesn't have PATS, I would do all your diag with it installed first.

Do you still get fuel pump codes?

Will the pump run with pins 30 and 87 jumped at the relay?

 

[540milotalon]

The pump did run with pins jumped out using the previous’96 PCM. I had the Autoparts swap out another one with me. I have not tried to cycle the pump by jumping the relay pins with this "new" '96 PCM but did try starting with cam sensor unplugged.
When I put the first ‘96 PCM in, it started so suddenly it really caught me by surprise. It would run until it ran out of fuel, jump feed the fuel pump, fill the lines, it would start and run until it cleared the fuel lines. Maybe ten times total, showing a friend or two that stopped by to pick up something, etc., Then, for no reason I can determine, it quit starting up. I let it run out of fuel the several times I started because she has no coolant. I had the system open, putting in the additional temperature sending units for the electric fans. System is closed today, ready for water.

But I guess the questions are; "Why does it no longer start?" And, "Why does the fuel pump cycle during the KOEO test but not to start it using the '96 PCM?"

 

[Mechrick]

At the fuel pump relay there are 4 pins.

pin 85--------------12v coil power in start or run
pin 86--------------pin 80 at the computer supplies ground for 2 seconds (prime pulse) at key on, and also when crank signal present
pin 30--------------12v power all the time
pin 87--------------fuel pump

-Since you can jump the terminals and make the pump run, the secondary (high current) side of the relay seems ok.

-Check the primary (coil) side with a voltmeter while cranking and see what you get on pins 85 and 86.

 

[540milotalon]

Well, when you forget to the check the basics?? All fuses good, all relays good, Fuel pump can NOT be heard running with key turned on, not even a couple seconds initial startup, pump can be heard running when terminals jumped out.
With pressure gauge hooked up there is ......ZERO pressure! The brand new, from Twilightzone auto parts fuel pump is running but producing ZERO pressure! That is why it quit running with fuel lines full, they weren't full anymore!
An engine needs air, spark and FUEL!

Still doesn't tell me why the pump wasn't working with key on, we'll figure that out as the saga continues.

 

[540milotalon]

Two (2) out of box BAD fuel pumps after the initial one that went bad after like 10 starts, I have a truck that sends an approximate 2 second signal to the fuel pump and then starts and runs!
Xxxxzone has junk parts!
It has a Carquest pump now.

Thanks for all the help. sorry to get y'all working on my wasted time project. I just expected their junk to work and never verified that was the problem. Trouble with swapping stuff around, you figure it has got to be something else you did wrong?

 

[RonD]

Good work

Thanks for the update, AND THE FIX

Yes, "new" used to mean "tested and works"
Now it means "you test it for us and we will replace it if it doesn't work"

Labor to test, i.e. quality control, is expensive now-a-days, so to cut costs manufacturers just don't do it

Ford, GM and other car makers require quality control, as they can't afford to install new parts that fail
This is why a Motorcraft fuel pump is $450, and a 3rd party pump is $150, 3 times the price in this case