It started completely out of the blue giving me trouble. The truck runs like a scalded dog once it gets going but randomly, off idle it seems to have a lack of power. It's like the power kicks in all at once. The idle does seem to be a bit irratic and not as smooth as before. It has also failed to start a couple of times but has had fuel at the injectors. I gave it a short huff of starting fluid and it cranked right up. There is no visible smoke from the tail pipe that is out of the ordinary.

The lift pump is fairly new and seems to be providing good flow and pressure to the injector pump. The check engine light is not on. I've ran it with the programmer on and with it off and there seems to be no difference. The truck has 365k miles on it and has the original injector pump (knocks on wood). I've never had to replace a sensor or any injectors/seals.

Ideas? Thoughts?

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Ok, I've done some more reading and it sounds like it might be the APPS. I'll follow the reset procedure and see if that does it.

1. Set parking brake
2. Disconnect negative battery cables on both batteries
3. Turn ignition key to run(to drain any remaining capacitors)
4. Let truck sit for 30 minutes( this is the recommended minimum)
5. Return ignition to OFF position
6. Reconnect both batteries and secure, not a timed event
7. Turn key to run position(not start) and depress accelerator pedal slowly all the way to the floor
8. Allow pedal to return to top position slowly
9. Turn ignition switch OFF
10.Release parking brake

 

APPS shouldn't affect starting.

Codes?

Any modifications?

 

365000 on stock injection pump...??? Really and its chipped thats awesome when you get the fail start i would recomend hot wiring it the get the ecm possiblity out of the way if all the other things have been checked ...filter.liftpump.bleeding.ect i would see what the hot wiring of the pump will do and if it still wont start you got a bad pump ...my opinion

 

It's cranking fine most of the time. When it doesn't crank, it stumbles and then stops. I let it sit a while and it starts up fine. The last two days it has cranked perfectly, it just has power loss at lower rpm, and then it bout gives me whiplash when it kicks in.

The only mods are a straight exhaust, a tuner, and a K&N. I just checked and the only codes are P0460 and P1693. The fuel gauge has not been working for a while so that doesn't surprise me.

I should add, all of this started when I was rebuilding the front end. I had the truck up on jack stands and was firing it up to cycle some fluid through the PS pump and that's when it started acting stupid. Completely out of the blue, while I'm giving her a cool $500 worth of steering parts.

I'm going to check for loose connections and such today and maybe do the above procedure just for the heck of it.

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Umm, I've never adjusted the valves. I'm an idiot. I probably should do that too...

 

Well, it's back to running like it should.

I adjusted the valves and they were surprisingly close to spec. They were all out just a bit though so I'm hoping to see my mileage go back above 20mpg. The cover gasket was still in good shape thankfully. I had no idea those were $125!

I did the APPS reset too. Honestly, I'm thinking that wasn't the problem either. I think it was all because one of my negative battery terminals was partially corroded. I cleaned all 4 and I'm planning to replace the cable ends. They are all the way tightened and aren't clamping good still. I think these batteries have slightly smaller terminals nowadays, not to mention the 14 years of wear on the leads. I may end up having to replace the cables altogether as there isn't much slack for cutting off and replacing the ends.

Thanks for the help.

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Well crap. It started doing it again tonight. Idles perfectly now though. It just randomly won't start without a short shot of ether and randomly has half power off idle and kicks in all at once. I cycled the switch and the only code it's showing is P1693. I know, that's the companion code but I watched it twice and that's the only code it is showing.

 

Well I scanned the codes tonight and it's got the injector pump death code. It just doesn't make sense that it runs fine most of the time and then cuts to half power. It won't crank on occasion but with a tiny shot of ether it fires right up. Time to shop for a pump I guess. I will probably find out it's the ecu after I swap it out.

 

Blue chip diesel is pretty awesome they loan you the tool to pull pump