Just replaced IP, not starting and still getting p1688 and p1689

Gravy

Gravy

Giggity Giggity
Joined
Apr 24, 2006
Messages
535
Truck died last weekend, went out and bought a new IP from FBD, put it on today, and the truck still wont fire. It is still pulling codes p1688 and p1689. Could it be an ECM or (if there is one) injector pump relay? Kinda pissed I blew the $1200 on a new ip and it didnt fix it but I guess its insurance and I feel safer about bombing it now. Any help, as always, is greatly appreciated.

And for those that dont know:
P1688
Internal Fuel Injection Pump Controller Failure

P1689
No Communication Between ECM & Injection Pump Module

-Greg
 
I did the clear codes and the lift pump did not die as I am getting good pressure. Gauge is not installed but will be tomorrow. Diesel shot about 15' when I primed the pump without the lines attached.
 
I do have a Banks Big Hoss Chip in there. I am going to try and find the wiring schematics on that to take it back to stock to see if the chip up and quit.
 
Stock IP getting 11.6 PSI @ startup. Still not firing.
 
did you crack a few lines to get the air out. We have almost ran batteries dead trying to get these trucks started after installing new pumps.
Jay
 
daytondiesel said:
did you crack a few lines to get the air out. We have almost ran batteries dead trying to get these trucks started after installing new pumps.
Jay
Click to expand...

Would that still give me codes those though?

Well, I take the Fp thing back. At prime, it reads only 4, maybe 5. After I try and start it and stop turning the engine over, it builds to 11.6. This seems kind of low to me. Am I right in thinking that?

So, I am taking tomorrow off work to finally get my vulcan big line kit and holley blue pump on there. if that doesnt work along with really bleeding the lines again, she is going to a shop.
 
leave lines 1 3 and 4 wide open and see if you get any fuel to any of them. Once you get fuel coming out of one of the open lines then close it and crank until the next one starts shooting fuel.
 
Air in the pump will not set those codes. either there is loose connections or you got a pump with a bad board.
 
You are definately gonna have to crack the injector lines to start it, at least two or three. You are gonna make a big mess but you can't avoid it. And you don't want a lot of pressure when cranking or it will start harder. That is why your computer bumps the LP when you hit start and then turns it off until the engine is running to the best of my knowledge.

Edit: On second thought, call Gus, tell him it is all his fault, and make him buy you beer! :hehe:
 
GRotman said:
Air in the pump will not set those codes. either there is loose connections or you got a pump with a bad board.
Click to expand...

Is there anything else in the electrical system that runs hand in hand with the IP and LP? I have checked all electrical connections at the IP, APPS, and ECM, cleaned them, and reinstalled them. I am thinking about ordering an injection pump relay for the main fuse box to see if that fixes it. Any other ideas?

-Greg
 
Check pin 7 on the injection pump harness for power, if that has power, then check pin 6 for ground. If you have both of those the truck should start and idle.
 
Just a crazy thought....but
I would take off the big nut on the pump shaft and make sure that the key was properly lined up in the keyway. It would throw things off time = no start and codes. Wouldn't be the first time this has happened.
Just a thought, probly not it.
 
I have verified the timing on the shaft numerous times, but I will check again. I will also look into getting power at the IP via pins 6 and 7. Thanks.

-Greg
 
Did you recently hook up the banks box? if so and you mixed up the ground and another wire you can fry the solenoid in the pump as soon as you turn the key on...don't ask me how i know this.

But basically by doing this you take a brand new perfectly good pump and turn it into a hunk of junk instantly as it ruins everything.
 
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