Okay, so I swapped out the 3.9 in my '97 Club Cab 4x4 for a 5.9 out of an '01 Ram Van.

Went pretty well. Pan was correct, flex plate came with motor, got a throttle cable, dipstick and fan shroud at the yard for $30. Got a computer on ebay and had it flashed by B&G. Added the wiring for the #7 & #8 injectors to the 6 cyl. wiring harness and got a new lower radiator hose.

Buttoned it all up today and hit the key. Fired right up, ran about 4 seconds and shut down like it ran out of gas. Same scenario repeats every time I start it. Starts VERY quickly...idles smoothly for 3-4 seconds and shuts down. No CEL, no codes, 50 lbs. fuel pressure.

What am I missing? Somebody out there must be able to diagnose this. Any ideas?

Rick

 

I would imagine the PCM you have is "security" enabled. That's what it sounds like , anyway. I did the same swap, and used the PCM from the 3500 Ram. I have no dash, only a message saying "no bus". However the truck still runs. I think any non-security PCM for a 5.9 should work, at least to drive. I ordered a reman from ebay and we'll see if it works in a few days.

 

agree. It's the security shut-off. Do you have the "gray key" that is grayish-brown (usually rubber) and kinda fat, or the "black key" which is hard, thin plastic?

When i had spare key made for my truck, i had the same problem. I had a gray key, they made me a black key. lo and behold, it would run for 4 or 5 seconds.

 

Well I dont know when they started doing chipped keys but even on my truck I noticed if you lock the doors the remote and then try to start it my truck will shut down after 4 or 5 sec and it wont start till I unlock with the remote when it does do this security flashes on the dash.

 

my mom's firebird is like that, but worse. If you lock it with the fob, you have to unlock it with the fob. If you use the key, the alarm will go off until you put the key in, and it can read the chip.

 

Thanks guys,

I'd have gone crazy trying to diagnose this without your help.

I'll call B&G in the morning and see what they can do.

I'm a little disappointed that they weren't aware of this problem when they did my programming....but they never even asked.

 

Called B&G today....they said to send it back and they'd reflash it. So its on its way. Just wish I'd known about this beforehand, but at least I know it'll run when I get it back.