New here. Been reading alot but thought I should ask before i throw a bunch of parts at the truck. I bought the truck 4 weeks ago. I have a 96 k2500 with 300k km on it. Not sure when the injectors were done. Problem is when under full throttle if the RPM stays above 2500 from a stop, it blows black smoke only after it goes into 3rd gear, and it stumbles untill I let off the throttle. The pmd is on the pump and dont know when or if it was changed. The lift pump is rusty but works good. There was a guage on the lift pump when I bought it and at idle it read 6lbs. I have a home made cold air intake that sucks from the hole in the fender with a huge, new clean filter and a 3.5" straight through exhaust. I changed the gas cap cause there was excessive vaccume in the tank and im going to change the fuel filter tommorrow. On idle I cannot move the waste gate. I do not have a boost guage on it yet, but I can hear the turbo under low RPM's up to 2500. Runs great untill sustained RPM above 2600RPM. Any help would be greatly appreciated.

I would want to know the fuel pressure when it is stumbling. If you can move the gauge at the LP to the cab.

Mine starts to stumble under load when the fuel pressure drops too low.

Is this happening under normal driving or are you pulling something? My guess is after you change the fuel filter and see what the PSI of fuel pump is under wot, you will find your problem.

Yes, it sounds like low fuel to the IP at WOT. Most likely cause a plugged filter. Could also be a bad Lift Pump, wiring/relay to the lift pump, kink/clog in the fuel lines, clogged tank, etc.

But as always, start with the simple stuff first. If you just purchased the vehicle, you should change all filters and fluids to get a baseline for change interval if there are no records.

I changed the fuel filter today and it is better but still does it. I have only done WOT without a load. I will put the guage back on it tommorrow and see what it does under WOT.

put the gauge pre IP inlet,there is where it matters what you see on the gauge.

And as I suggest to every new 6.5 owner, check the harmonic balancer NOW (avoid a broken crankshaft) and get that PMD mounted (with a cooler) anywhere but it's stock location (avoid getting stranded on the side of the road). You may also want to seriously consider a new set of injectors ASAP as well - old injectors will cook pistons, especially under towing (and even WOT like you are doing) situations. 300,000 Kilometers is about 186,000 Miles and they are a "Replace" maintenance item at much less then that, and typically a lot of 6.5 owners neglected to do that because of the cost at the time. Now it's cheap (<$300) and a lot less costly then rebuilding your engine.

I put the guage on and at idle it is 5lbs and at 2100 rpm (cruising) it's 2lbs. Under hard acceleration it drops to zero. Could it be the sock in the pump on the bottom of the suction tube in the tank or the lift pump? If its the lift pump which one will work without killing my wallet. Can I use a gas fuel pump or does it have to be for diesel?

Also, How much PSI is too much for the IP?

ck in the pump on the bottom of the suction tubeI put the guage on and at idle it is 5lbs and at 2100 rpm (cruising) it's 2lbs. Under hard acceleration it drops to zero. Could it be the so in the tank or the lift pump? If its the lift pump which one will work without killing my wallet. Can I use a gas fuel pump or does it have to be for diesel?did you try a new filter?
Idle should show 6 min.
Cruising should be 4 or better
WOT should still be at least 1

A 93 stock LP gives the best pressure,wont break the wallet.

plugged sock in the tank is possible,blow the line Pre LP back to the tank(compressor),see if it improves things.

Any vac in the tank at a refill?

did you try a new filter?
Idle should show 6 min.
Cruising should be 4 or better
WOT should still be at least 1

A 93 stock LP gives the best pressure,wont break the wallet.

plugged sock in the tank is possible,blow the line Pre LP back to the tank(compressor),see if it improves things.

Any vac in the tank at a refill?
I changed the filter friday and the gas cap on wed. What about that mr gasket 12d fuel pump? http://performanceparts.com/part.php?partID=414573

Nice looking pump,price is right,min pressure is to low IMO.
Quality may not be there ? Only way to find out is to try it
Stock 93 does better.

its your call

I'm also new to the 6.5 OWNERS. I purchased my '99 GMC K3500 CREW CAB DUALLY a year ago with 84K miles on it. I have a tad bit over 101K on it in that year. I've installed in the last 2000 miles- NEW LIFT PUMP, PMD KITw/ cooler, WASTEGATE SOLENOID, NEW ROTORS AND HUB BEARINGS; FUEL FILTERS every 6K and ROTELLA every 3K. I'm aware that the 6.5s require severe maintenanced attention every 100K. So next on my list is the MARINE injectors, harmonic balancer.Question is, what brand is the best and is there a HARMONIC BALANCER available that I will not have to change every 100K? I would like to add some power along the way as well and wrestle with these DURAMAXES and CUMMINS'.

Search for "Fluid Damper" here in the 6.5 forum - there is a great fluid based harmonic damper (hence the name) that is well regarded and sold by a vendor here. It's pretty much (based on what I've heard) the last harmonic balancer you'll ever have to buy and is better then any standard model. I don't personally use one but have heard nothing but good things.

IMHO, don't bother with the "marine injectors" - little to no performance improvement, possibly worse MPG. Make sure you go with genuine Bosch/AC Delco/Stanadyne - no eBay junk.

IMHO, don't bother with the "marine injectors" - little to no performance improvement, possibly worse MPG. Make sure you go with genuine Bosch/AC Delco/Stanadyne - no eBay junk.

Most of the time the "no e-bay junk" is correct. However I just got some Bosch, made in India, injectors, had them pop tested and they all came out uniform at 2200 PSI. They cost me $235 shipped and were shipped very quickly. They do not come with the copper seals or return lines so you'll have to find another source for them. The source I found online and was for less than $30.

I did not just randomly order off e-bay. I got info from several other satisfied purchasers on another diesel forum before my order. Several of these purchasers had their injectors pop tested with good results. Some installed them without pop testing and gave excellent reports. I think I still have the sellers info if anybody is interested.

Don

I ordered mine directly from Kennedy Diesel in 2008 for about the same money, got the copper seals, all new return lines, and intake manifold and turbo gaskets (presumably in case you decided to pull the manifold/turbo for the job) all included.

IMHO, a more reliable source, probably a bit cheaper in the end, and less hassle then trying to source multiple items from multiple places.

That, and if you have an issue you just give Kennedy a call - they know their stuff and will gladly spend a few minutes with you on the phone to help out.

Okay. Thanks to the both of you for the info. I was eyeballin' the FLUID DAMPER unit anyhow, but needed some reassurance from the masses. What is KENNEDY diesel's web address or phone number?

What kind of additional horepower numbers are available with these TD 6.5s? Is there anyone making a DIRECT INJECTION conversion kit for these engines?

I would love to be able to obtain 350-400hp from this engine. Is this crazy talk, virtually impossible, or a dream?

What is KENNEDY diesel's web address or phone number?

http://lmgtfy.com/?q=kennedy+diesel

Is there anyone making a DIRECT INJECTION conversion kit for these engines?

Nope.

I would love to be able to obtain 350-400hp from this engine. Is this crazy talk, virtually impossible, or a dream?

Possible if money is no object and you're handy with rebuilding it from the ground up to handle that sort of power but not very realistic otherwise.

@handcannon- Where is the link for the $235 injectors.

@privatepilot- kennedy diesel's injectors are $600 these days unless I'm looking in the wrong location.

Please advise.

I don't know anything about making a link, but he goes by moneyslave and the sale number is 140393596399.

Don

Just to update about the injectors, they are now installed. My truck runs good, seems to idle smoother. I don't know how long the old injectors were in there. But, my PO had the truck for over 60k miles and had never changed them.

Don