Trouble after pump install

[MEDiesel]

I need some advice. 4 weeks ago, I got water in my 2000 3/4 ton 6.5 .It got by a 3 day old filter and destroyed my IP. I had my pump rebuilt to spec,the GM mechanic put it back in,after flushing the system,here's my problem. The truck has a very rough idle. Starts good, but I took it out around the lot,it feels like it's missing or out of time.I need help. What can I suggest to my mechanic to help resolve this?Also, no codes. Thank you in advance,I need my truck back.

[gmctd]

Initially, it sounds like air in the fuel lines. Hopefully he purged the fuel tank, filter and lines of all water.
Have him re-purge the fuel filter, supply line to the inj pump, and the injector lines for a start.
A Tech II may show cylinder imbalance codes, which may not be stored.

jd

[MEDiesel]

Thanks, I'll try that. Any other thoughts?

[tom.mcinerney]

Agree w GMC. Bleed all air from filter cannister; but it's probably air in an injector line. Not uncommon(from posts this forum) for a fitting to loosen on the fuel injection pump soon after an installation; but start by cracking injector lines till they bleed fuel at injectors, in turn.

[ucdavis]

Air is suspect since system was apart.
Also did you get new fsd w/rebuilt pump? If yes & if this symptom is new w/rebuild, could be bad fsd even tho new.

[MEDiesel]

Just came back from dealership. They found the harmonic balancer key sheared off,and it was turned 180 deg. They will have it back together in the morning ,I'll post the results. Has anyone heard of this happening? Can someone give me details of the best water separator setup? I have a Fleetgard sep. coming,thinking of setting it up before the lift pump. Any help would be appreciated.

[ucdavis]

As long as the HB is off, I'd have a new one put on if it was me and I had any serious mileage on.

[MEDiesel]

I only have 82,000 miles on it. I don't think I can stand waiting any longer for it to get out of the shop.

[ucdavis]

82K is a great time to do a new one; over 100K they get suspect, and when they go bad you get some really great noise then a broken crank if you don't catch it in time. Just my $.02

[tom.mcinerney]

The 'best' separator setup is a matter of dispute. There are lots posts on filters / lift pumps, here, but especially in Duramax forum. Some filter assemblies are designed to operate under pressure, others under vacuum.
Strongly suggest careful inspection of both harmonic balancer and crankshaft-serp-belt drive pulley. It's possible that crank pulley failed, causing HB key to shear. As UCalDavis suggests, this generally results in broken crank/block.
More Power compiled a couple outstanding articles about the crank/HB. The cranks last indefinitely if the attachments fore and aft are in good condition. With a bad HB, crank pulley, or flywheel, the cranks crack....

[MEDiesel]

Went to the dealer, Lee GMC in Auburn, ME ,and drove my truck this morning. Seems real good. I think I got Lucky that the HB sheared when it did. Tomorrow they are putting in a new HB ,then I should be good to go. Should the HB and any trouble arising from it,be Under warranty? The mechanic that took it apart said the HB bolt was loose, turned it out with his fingers. Why would that happen? Thank you in advance. BTW,if anyone here is in my neck of the woods, Lee GMC in Auburn,ME has some great mechanics,Notably Kevin Blazer. He actually cares about doing things right,and he's quite knowledgeable.

[MEDiesel]

Got my truck back Thursday. Going good so far. Trying to get GM to warranty the harmonic balancer. Doesn't make sense that the bolt was loose. Going to put a Fleetgard filter assembly with sensor + heater in before the lift pump. Once I get that done, I think I'll put exhaust + gauges in. What is the difference between Kennedy + BD exhaust ?

[MEDiesel]

I meant Banks exhaust.

[MEDiesel]

Truck is going good so far. I'll fill up tomorrow,using Stanadyne Treatment. Hope my mileage is up. Learned my lesson with small fuel stations.

[96turboSuburban]

ME,
I have the kennedy in mine and it runs great!
Really has a lot of get up and go and turbo breathes really well, now I have to replace my HB!!! :eek:

[MEDiesel]

I also lost my H.B. , luckily while it was at the shop. It is running great now. I think I will go with the Kennedy Exhaust.Did you go 3 1/2 or 4" ? Good luck with the balancer. Todd

[MEDiesel]

Last week,I finally got my Fleetgard filter set up .It is located on frame of bed,before lift pump. Has a water sensor in plastic bowl,hooked to factory sensor wiring. Hopefully this will warn me before it's too late.Truck is running great. Think I'll do a Kennedy exhaust + gauges next.