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ScottG's avatar
ScottG
Nomad
Oct 13, 2017

Should have used Fuel additive

Just picked my truck up from the shop. It was having to spin more and more to start this past year. After that it ran great but the slow starts were starting to worry me.
I'd heard that we should use a fuel additive because ULSD has such poor lubrication properties but I blew it off. After all, it always ran great although my mileage has gone down. And how bad could it be with only 108K on it.
Boy was that a mistake. Shop said high pressure pump (CP3) was digesting itself and sending metal through the injectors. They told me it was purely a lubrication issue with ULSD.
So to go along with my new pump and injectors, I have a case of Stanadyne that I will use religously.

In order to get something out of this, I had the shop (DDP Monroe, Wa) install a set of their Honed and flow matched 50 HP tips. We'll see. I don't know if I was down on power before the work but it sure pulls nice now and has tremendous throttle response. It's very quiet too. According to everything other owners have observed, I should see improved fuel efficiency with these tips.

I hope new trucks can deal better with ULSD's lousy lube quality.

YMMV!

52 Replies

  • Scott, that's very unusual I think. I don't know anyone who's lost a cp3, ever I think. And we all run the same fuel.
    Are you certain it was not just injectors?
    Failing IP wouldn't run strong, low fuel pressure. Hard cold starts but runs fine are classic injector high return rates. IP can't make enough pressure to trigger the injectors with high returns when cold, but once it kicks, the IP can keep up.
    Well should run like a top again.
    Did you have lower injection pressure than commanded?
  • Gov't said USLD was much better for you:)

    Most fuel out of the pump is filtered at 20 micron. According to brother in law, retired tanker driver. I have additional filtering down to 2 micron. I've got older version than you... VP44 which is junk IMO. I've done a bit of reading on the HFFR or the lubricity of diesel fuel and ULSD doesn't score to good in the lube dept. (ULSD does score high in metal wear dept though) Thought the CP3 system solved much of that problem, even though there injectors are a fortune. DPP injectors I understand are true quality (the in house ones he makes special)