I replaced my trucks computer with an exact used one. Now, truck will turn over but will not start. I also put the old computer back in and same thing happens. The only other change I made was to run a new "check engine light" wire from pin 2 of the computer to pin 9 of the cluster connector. Do I need to have the new computer programmed?

 

So does the CEL now work?
Does it come on with key on?

50/50 test
Spray fuel into the engine manually and see if it fires/starts
This will tell you it is a spark issue or fuel issue

 

Ron, I put the new (used) PCM in and installed the connector at the PCM and installed the 3 connectors on the cluster. Turned key to "on". All cluster lights came on EXCEPT the brake and check engine lights just like original problem. I grounded the wire going to pin 2 of the PCM and check engine light still does not come on. I also checked the bulb with an ohm meter and it is good. So, I have ordered another cluster that says it was tested and everything works. It should be here on the 17th. So yesterday, I thought I would just start the engine to charge up the battery. It turns over but will not run.

The only thing I have changed is running a new wire from PCM pin 2 to the cluster connector pin 9 and putting in the new used PCM. I even swapped the new one with the old one and the engine still will not start.
I will give your suggestion a try and see what happens and let you know.

 

Well its not THE ONLY thing you did, because none of that would effect starting, lol

Without the CEL you won't know if computer is actually powered up
As before you can test pin 2 to see if its a ground with key on, that means computer is powered up and ready to start engine, start spark and injectors

Fuse 19 in cab fuse box powers the coil pack, fuse 13 in Engine fuse box powers computer

 

Ron, I ran your test. Sprayed fuel into air intake. Engine starts and runs for a few seconds, so I have a no fuel issue. I checked the fuel pump relay by swapping it with the AC relay. Still won't run. Checked the fuse for the fuel system and it is good. Not saying it didn't, but I just don't see the fuel pump working one day and not the next. I hope it's not the pump. I slid the bed back to replace filler hose and I don't look forward to doing it again!!!!. I read where someone suggested to take a biece of wood and bang on the gas tank to shake loose any dirt that may be plugging the pump. Seeing if the pump is running when key is in start is my next check. If it is then I will try the bang the tank idea.

 

Ron, I know you are busy helping others, so I will make this short. Where in the engine compartment can I open the fuel line from the tank to see if the gas pump is pushing fuel to the engine?

 

Engine OFF
There is a fuel pressure test port on the engine's fuel rail, looks like a tires air valve........because it is, its a schrader valve, may have a cap on it like a tire's air valve, take the cap off
Has a pin in the center, press it, but watch out, should be 30psi pressure in there if pump is working, so fuel should squirt out

You can cycle key on and off a few times to build up pressure then test again

Well 99% of the time a fuel pump just quits one day, no warning
Hardly ever quits when driving, just one day on start up, no fuel pump

1% of the time it can be intermittent, starts to work again, banging on the bottom of the tank can work, but pump is done if that does work, lol, change it or you WILL be stranded


Long shot but free to look
In the cab, passenger footwell, up on the firewall behind the glove box is the Inertia switch, fuel pump power passes thru this switch
if there is a sudden stop(accident) or rollover, the weight inside this switch will shift positions and "TRIP" the switch, cutting power to fuel pump

Picture here: https://www.therangerstation.com/for...lug-jpg.51618/

It has a RED button on the top that will Pop Up if switch has been tripped, it can be pressed down to reset the switch, but it will trip again if you slam a door hard or go off a high curb, lol

 

Hi Ron, just to bring up to date. Looks like we will be holding a fuel pump funeral. I am almost positive it is dead. I found the test port (after some hard searching) and when I pushed the pin nothing came out. I turned the engine over several times and checked it again. Still nothing coming out. Next I had my wife, who by the way, can hear a cricket scratch his *** a block away, super sensitive hearing) listen at the filler cap while I turned the key to start and no pump motor sound.
The only other thing I will do is: 1. Remove everything out of the truck bed, remove the shell, remove the bed bolts and wiring connections and slide the bed back enough to get to the fuel pump. I will then use a test light to see if there is voltage at the pump connector. If there is I will then remove the old pump, order a new one and do it all in reverse. I thought about dropping the tank but it is full and I don't have enough containers to hold all the gas, so as I had slid the bed back to replace the filler hose I know exactly how to slide the bed back enough to get to the pump. I am also waiting for the new cluster, hoping it will fix the two cluster lights that will not come on.

I should become a mechanic, but at 75 I don't think so.
Phil

 

The fuel pump only has power for 2 seconds, when key is turn from off to on, never has power in START
So just turn the key on and off a few times when testing for voltage, should see 12v but just for that first 2 seconds when key is turned to on(RUN)

 

RON, Thanks for all your help. I will try to keep from bothering you until I get these issues solved and fixed. Today and tomorrow I will be emptying the bed of the truck, removing bolts and taillight wiring and sliding the bed back. Once I have access to the gas pump I will test the wires to determine if I have power to the pump. If I do then I will order a new one and replace when it arrives. The new gauge cluster is due to arrive Friday so I can work on the two bulb issues while waiting for the pump.

Thanks for all your help.
Phil

 

Ron, I said I wouldn't bother you again but I just need to verify something. I just ran a jumper from the positive battery post to the pink pin on the pump. I then used a tester with a 12volt bulb and touched the pin that would be pump ground. The bulb in the tester lit up but I did not hear the pump run. Can I take this to the bank that the pump motor is bad?
Thanks,
Phil

 

Sorry for the late replay

Yes, pump is bad

 

Thanks Ron. I will order a new pump today. I can get it in 3 days.
Phil

 

A loose connection allows oil vapor and dust to infiltrate the 104 individual connections to the PCM. Clean the connector and the PCM pins thoroughly, and then do it again. Tighten the bolt securely to get the best contact and environmental protection. The way it is designed it would be the hard to over tighten the bolt without trying.