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View Full Version : 6.5TD Will Not stay running, Hard to start, then shuts off after bucking/kicking?



97Suburban
01-07-2015, 11:53
Hello Folks,

(is the DieselPlace & TheDieselPage the same folks or competing forums or companies, i have no clue?)

I am in need of some desperate help http://www.dieselplace.com/forum/images/smilies/confuzeld.gif

My truck the past several months was seemingly loosing power, if i pushed it harder, but i thought it was a dirty fuel filter...?? (last time it acted like this, it was the FSU, fuel sending unit sock assembly)

Meaning, it ran fine at startup, ran "OK" with normal driving around our rural town, but if i had an open roadway, and ran it harder in a rush &/or if i would stomp it to blow it out for a short distance(100 yards or so), and it would take off fine, but was short lived... meaning it would start to loose power and start to kind of bog/loose power, but i would let off immediately fearing a dirty filter and causing a lean condition, not wanting to burn up a piston, etc...

So i finally changed the filter, but that did NOT solve it, urggg http://www.dieselplace.com/forum/images/smilies/banghead.gif

THEN, a few weeks after changing the filter, it started doing some random bucking and kicking, so we would have to go easy and back off at times.

But then it got so bad real fast and could no longer drive it (and fearing breaking something). But then it immediately went real bad, totally unusable and bucking/kicking non-stop!!!

* Meaning, you would have to crank the heck out of it and HOLD the throttle to the floor until it fired and started up... or hold the throttle at a third to half get it to start up, but then it bucks and kicks and carries on if you go past idle; and sometimes you have to pump the throttle & hold it to keep it running, but then in a min or two, it stalls http://www.dieselplace.com/forum/images/smilies/banghead.gif

So with more testing, here are more details:
* So, if i allow the lift pump to pump up to 6 lbs, then hold the throttle to the floor, the truck will start after a long cranking session of maybe 30 seconds or more, then once i get running, i can actually let it idle and it will idle for almost 5 minutes, but get this, the pressure actually drops while it is idling, and slowly drops after a min or two and rapidly drops to zero and the truck shuts off. So this is really confusing, is the lift pump maybe heating its coil or motor up and stopping after a few mins and fooling me? (HeathDiesel.com just shipping me a new heavy duty lift pump, should be here by friday i hope)

* NOW to really confuse us, i also have another lift pump i kept from when i put the heath lift pump on in 2005, and i kept it as a backup, and it is the one doing this symptom right now. so both "OLD" well work lift pumps give the truck bucking and kicking, i suppose they both could be weak or bad, but confusing????:(

Q&A #1: should i maybe have the lift pump pull from a 5 gallon Diesel jug from the intake side of the lift pump with a short 2 foot piece of fuel hose to rule out the fuel lines collapsing of the stupid Fuel sock being the problem again?????

Q&A #2: Hmmm, you know what, could the RockAuto.com FSU / fuel pickup unit and sock be clogged and doing this starvation thing???
That would be a much easier and cheaper fix than a IP replacement !!



* NO check engine light is on, and i do NOT have a code tester, but would there be any codes if no check engine light is on??

*where can i obtain a cheap code reader for this generation truck, what is it OBD or OBDII or something?



So Not sure what it is, but i suspect one of the following???
1. So with the parts so far, i am kind of hoping maybe the fuel sock again,

2. and i really hope that it is NOT the Injection Pump, it was replaced as noted below at 98k by the GMC/Chevy dealer and now at 195,392 miles, so less than 100k miles??????????????
(Does Chevy or Stanadyne warranty the Injection Pump for 100k miles (someone said they did???)http://www.dieselplace.com/forum/images/smilies/think.gif

3. or could it be some other Fuel starvation issue causing it to drop from 5lbs to 2 lbs while bucking and kicking and then shutting off?



Parts replaced and work performed since, but no success:
1 replace fuel filter
2 replaced the OPS (Oil Pressure Switch)
3 replaced starter relay (i know, but someone said it is par of circuit?)
4 replaced fuel pump relay
5 cleaned up the 3 grounds to intake manifold and ground strap on frame.
6 hooked up a Fuel gauge to the T-valve
5/6psi = turn key on
3/3.5/4psi = once it starts after 2 mins of cranking
2psi = as it bucks and kicks for maybe a min or two, the pressure actually drops slowly from above pressures to 2 lbs then shuts off.
Then the truck will NOT start for maybe 10 or 15+ mins....????


Past Info/Repairs
** Today 1/6/2015 the truck has 195,392 miles on it.

** In 2009 it was falling on its face and i think some bucking and kicking or something strange going on, so the gentlemen of HeathDiesel.com had me change the OPS & Relays and that fixed the issues & ran PERFECT!!!!

** Then about a year ago, it was bucking and kicking & heath swapped out their PMD under warranty and that fixed the issue, ran PERFECT!!!

** Fuel Tank pickup replaced = 10/08/2012 182,100 miles swapped out the Fuel tank pickup unit/sock assembly for the 2nd time. (1st time was 1/11/2010 with a RockAuto.com unit). This fix SOLVED a lack of fuel & ran perfect once again!!!

* 1/11/2010 Replaced rusted fuel lines with fuel rated NAPA rubber lines, from fuel tank unit and up the frame to 6" of lift pump for the one line and all the way up to engine frame curve for other line. Ran fine starting up and driving around town lightly, but would starve for fuel if i stomped it, and this solved the issue!!!!!

* Both New 900cca Batteries this past summer.

History of my Truck
* Always ran extra oil in the fuel tank or the AMSOil Diesel Fuel treatment at first, that or cheap motor oil, then I switched after a year or two to 2-stroke motorcycle oil (to not build up carbon on the pistons and heads)

I shopped for 6 months in 2005 before i bought this 1 owner 1997 GMC Suburban 6.5TD with 120k miles on it !!!

I got most of the records & dealer repair info from the woman who babied this thing. She had massive work done to it at 98k miles, and she knew everything about this truck, mint condition, new fuel tank, new Injection pump, new a/c front & rear, all dealer serviced, and she used Stanadyne fuel treatment, etc.

Since owning it, Heath Diesel set me up with their parts:
1. ECM for fuel economy 123k
2. Heath Turbo controller arm
3. Heath Remote mount PMD at 123k miles and mounted up under front bumper, on that plastic plate where Heath have us mount it.
4. New harmonic balancer (i bought directly from dealer) 123k miles
5. Heath Diesel Heavy duty Lift pump
6. I added 3 column gauges: Boost, EGT & Trans temp
7. I replaced the injectors Jan 2009 at 155k miles

** Full Trans & converter flush via local shop every 3 years.
** Trans Shift kit & new solenoids from same trans shop (so that it would shift quick and clean and not drag tranny because i wanted to tow enclosed 5k trailer up and down PA & New York mountains, etc)

* 410 gears
* clear CAT
* I have used AMsOIL, Rotella-T, Dello, etc...
* Mobile 1 best filter
* Prestone 150k fluid full flush at 134k miles, now 195k miles 1/2015
* Rear fluids replaced with AmsOil fluids 123k miles 1/2006
* Afe Air filter, then AmsOil Air filter, now commercial Baldwin Heavy Duty Air filter fall 2014
* Replaced Oil cooler lines twice now, using RockAuto.com lines (Feb 2008 RockAuto & then again 5/1/2013 RockAuto) (and OEM dealer oil line fittings to engine block)
* Replaced brake lines on frame with high end NAPA coated brake lines winter 2010.
* oil filter housing 'O' Ring, but still weeps, what a pain...why? http://www.dieselplace.com/forum/images/smilies/banghead.gif


* Glow plugs Never changed by me, and not real sure if the former owner swapped them or not???? so either new glow plugs by owner at 95k or maybe originals now at 195k here in Jan 2015...? (I guess i should do this asap this winter)


Thank you in advance for all your help!!!
http://www.dieselplace.com/forum/images/smilies/thumb.gif

zrocket
01-25-2015, 12:47
I didnt read the whole post.... but did you check the return line to the tank that must be clear not kinked or it will cause that .

JTodd
02-11-2015, 19:46
Sounds very similar to an issue I had and it turned out to be the short length of rubber hose just behind the fuel filter canister. There is a hard line from the lift pump, but about a 9" length of rubber hose that transitions between the hard line and the canister. The rubber hose makes a 90* bend from the hard line to the canister and it had kinked. Over time it got worse and worse as the line kinked more. Once found (by shear happenstance) I replaced the line with two shorter pieces and a barbed 90* fitting. No more problems. It sure sounds like that is your problem.