Lost lift pump and this morning I have the p1689 code.  Truck still starts but guess the airdog took out the injection pump also.  I think that it is just barely under warranty. Ill have to check.

P1689 code is more of alternator issues than a lift pump. I would test the alternator for excessive AC noise first. Then dive into the P1689 code article and do a bit of bench testing. 

 

Thank you  Mike.  I have been thinking that I should do that anyhow.

The lift pump failed and I was driving in very heavy traffic in Phoenix, AZ pulling a car I just picked up. it was at slower speeds  so I didn't notice it for a long time.  I think I drove about 80 miles or so without it.  I am sure it didn't do the injection pump any good but it will still start and run.  The lift pump is an Airdog FRRP  and is under warranty so I am waiting to hear from them while working on my new (to me) SUV.

No worse that the truck sitting in my yard with a dead lift pump ZERO fuel pressure and it was driven from east side of Wyoming to west central Idaho with zero fuel pressure. Still starts a runs fine so far, no codes, no problems but really does need a good lift pump. The owner is going to be getting a FASS 150. Just waiting... 

That does make me feel a good bit better.  The truck  isn't going to move though until a new lift pump arrives.  Not taking any more chances.  Back to work on the Isuzu Trooper for now.

Thanks

FWIW I lost my oe lift pump at 150k. Truck just died. I had no gauge to even no how low the pressure was. I ran that pump another 70k before replacing it. It had not died but went thru another bout of low fuel pressure with the in tank pump dodge gave me. I had extra money then and just replaced it not wanting to get stranded somewhere. All this was before finding Mike's farm here. Knowing what I know today I dont think I would have replaced when I did. But you really never know, I have seen folks loose both at the same time and others such as myself loose one and not the other. Kind of a crap shoot. Good luck with yours.

Thanks.  I will talk with Pureflow tomorrow and see about getting a warranty replacement on the way.  For some reason the lift pump just quit.  I went out this morning and unplugged the pump and then made a direct connection to the battery to verify that it wasn't in the truck wiring and the pump wouldn't make a sound so its definitely DOA.  It'll be running by next weekend.  

Got the replacement Airdog from Pureflow and it is running great again.  Thanks for all the advice.  

I have not tried the alternator AC check yet.  I do not know if my meter is sensitive enough. And it has not thrown another P1689 code.

As soon I Pureflow the serial of the failed lift pump the sent one right.  I had to pay the extra $68 to get it second day delivery though. They didn't even ask for the old one to be returned.

Thats the same experience I had. Good to hear a satisfactory conclusion.