1996 GMC K1500 6.5TD needing some insight.

[swany211501]

- Year: 1996______
- Truck model and class K1500_________
- Automatic or Standard - AUTO__________
- Mileage: 246000 KM _________
- Replaced parts and mods - To date Front to back - Battery terminal mod, 2/0 gauge battery cables, block heater cord, glow plugs, cooler lines, pmd on heat sink behind front bumper with PMDcable cable, #9 resistor, oil cooler lines, glow plugs, lift pump (93 HO oem replacement) regular filter changes, glow plug bypass mod, ect fooler, new alternator, new starter. 2.5 inch x over 3 inch down, 4 inch straight through. Tranny pan, ___________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? S, Turbo
- Ambient outside temp: (indicate *C or *F) From -50*C to +10*C
- What fuel are you using? CO-OP winter grade
- What fuel additives are you using? Howes, ND-30W or 2 stroke
- Where are you located? Estevan SK Canada

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter 4 months ago checked clean
- Fuel filter 1000km ago
- CDR Valve? unknown
- Coolant – last flushed/replaced at unknown
- Oil – synthetic/regular, changed at - Synthetic, Petrocan 10-40W 1000km ago
- Batteries – state of charge, (matched set) replaced at - Unknown, matched, good
- Battery cables and grounds (removed, cleaned and tightened): Just cleaned and tightened during alternator and starter change
- Glow Plugs - how many miles on them?15000km What type?Bosch
- Injectors - last changed at - unknown


History: (Describe how the problem first appeared.)
- What were you doing when it happened? ______________
- How was the truck running fine before this problem appeared? It's becoming apparent that this is the reason the truck was sold.
- Has this problem ever happened before? _______________________
- Describe any related factors that might be part of the problem.
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) Y And? P0406 P113


Diagnostics:

1] Starting:
1a] Does the engine start? Y
1b] Does the engine crank over? Y
1c] Are your batteries fully charged?Y
1d] Have you removed, cleaned, and tightened all battery connections? Y
1e] Does your Wait to Start light come on for a time? How long? Y 10 SECONDS
1f] Does your glow plug light come on? _________ For how long? _________
1g] Do you see smoke from the exhaust while cranking? What color? Greyish, followed by a white plume in the middle, very rare it's black.
1h] Does the Service Engine Light Glow during Start/bulb check? Not sure, dont remember
2] Fuel Issues (if not running):
2a] Can you hear your lift pump working?
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? _________
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? ___________
2d] Loosen an injector line and crank the engine - does fuel come out? _________
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? ___________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) ___________
3b] Condition of Extension harness (if used) Vendor or Homemade? _________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. _________
3d] PMD Make: ___________
3e] PMD Age: _____________

4] Stalling Issues
4a] Do you experience stalling only when hot? ____________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) ______
4c] Does pouring cool water over the IP seem to help with restarting? _________
4d] Is stalling momentary (engine recovers)? _________
4e] Does SES light come on when engine hiccups? _________
4f] Does cruise control quit working when engine hiccups? ___________
4g] Does re-starting seem to reset engine, restoring cruise and power? _________
4h] Changes to dash lights or instruments during stalling events? ___________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? Not sure
5b] Any bubbles or oil film in coolant overflow tank? N
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? N
5d] Excessive white smoke from exhaust on cold start? N
5e] Excessive black smoke from exhaust under hard acceleration? N

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? Acquired not installed
6b] Maximum boost under load? ____________
6c] Have you added a performance PCM (reflash) or Chip? N
6d] Have you changed exhaust / downpipe / crossover? Y
6e] Wastegate – mechanical or vacuum (OEM)? OEM, soon to be a mechanical

7] Temperature-related Issues:
7a] Single or dual thermostats? Single I think.
7b] Have you replaced them lately? Manufacturer of replacements? No, next on the list with hoses and a flush.
7c] Have you pulled and cleaned Radiator and coolers lately? Washed with pressure washer in truck when oil cooler lines were replaced
7d] Have you replaced the fan clutch? Manufacturer of replacement? N
7e] (winter) Have you tested your antifreeze? Good to what temp? Y -40*C
7f] (winter) Are you using a winter grille cover? N

List and describe any other factors which are not addressed in this checklist.

I've replaced lots, repaired lots and I'm starting to loose my mind on what seems to be needing fixing, replacing. I just finished replacing the alternator and the starter, both original, when the vacuum pump decided it should take a crap on me. I'm positive it is this, as I took the hose off of it and the thumping like noise got louder.

While doing the most recent oil change, I had a few issues. The cruise wouldn't work, there is an oil leak, and I needed to grease.

So I dropped the oil, found my leak - coming from between the TC cover and the pan, figuring rear seal, but the oil was old and probably getting thin so it leaked. Moving on. I got my new PMD cable so I removed my PMD and cable, which was an EDAM ebay one, the PMD and cable were both corroding at the pins. I installed my PMD that was on the truck when I bought it, a DTECH, installed a #9 resistor and the new cable, new ground and lots of dielectric grease. Cruise works, truck started good stuff. Changed the oil, checked the air, changed the fuel filter, bled the lines, forgot bleeder was open, hosed truck with fuel, closed bleeder truck runs good. Finally had my pressure gauge there, so I plugged in on the return line going to the water drain. Opened that up, put the gauge on the hood and started up. 2 psi at idle, vacuum at 2200+/- rpm. I've always had this problem with hard starting in the mornings or after sitting a few minutes so I got some clear line and put it from the #1 injector to the return line. Started the truck, ran it for 20 minutes, and watched a steady stream of pin bubbles and a big bubble the size of a dime u-tube through the line.

I know this is a huge post, lots to read. Help me decipher what's wrong here please? I have all the parts to do many mods. I bought enough 3/8's line to go from the tank to the FFM, I have a drill bit and tap for FTB, I have all my fittings to go from manager to IP. I have a new lift pump that the mechanic at work gave me. Stewart Warner 6-8 PSI. With the vacuum pump going to pasture, I figured I would make myself a TM and block plate my egr and get a shorter belt. But with all of this, I want to make sure I'm not throwing money away at a problem when it was something simple in the first place.

Edit - I have not yet done away with the pump. The codes are not the problem. I have a pump on the way out, bubbles in my lines, I have a hard starting truck, and looking for answers. My questions are what to do. Should I replace the fuel line from the tank, or should I investigate further, should I replace the LP with this Stewart Warner or stick with my factory first. Is there something else I should be doing here, or should I just replace everything because I have the parts and it won't hurt to do so.

Thanks for the look, any helpful input is generously appreciated.

Frank

 

[ak diesel driver]

So I assume the issue is the codes? Not real clear what your asking. At least 1 of those codes is egr related and you said you did away with the vac pump which is needed for the egr. Personally I'd go with a chip with egr delete.

 

[buddy]

I think your time replacing fuel lines and the lift pump will be well spent. Although I would offer the suggestion to use a stronger lift pump. the stock unit from 1993 is better, or something aftermarket could be much better, such as the Walbro FRB5 or the latest FRC10 that PMDCable.com is selling (although Leroy is traveling back to the states in the next week and its not up on his site yet).

The air in the lines will cause all sorts of havoc. Had you tried seeing if the air bubbles can be seen on the IP inlet?

If inspection does not reveal an issue with lines to the fuel tank, a crack in the Fuel Sending Unit inside the tank would also casue this grief, and good to make sure the tank sock isnt clogged as well if dropping the tank.

 

[tanman_2006]

x2 start with a new LP atleast a 93 model which should be good unless towing alot or wanting to push the limits, if not go walbro. That should bring up the pressure at the water drain.

If there are bubbles at the IP inlet then I would drop the tanks and plan on installing the Metrum Rod from PMD Cable and a sending unit.

Next the lines are your problem.

If the Vaccum pump goes down then the egr will go out and you also wont have boost. Block off the egr and start looking for a vin F intake and a tune. Replacing the vaccum pump would be cheaper if money is an issue and a tune is out of the question.

 

[WarWagon]

I guess it doesn't matter if you get bubbles on the INJECTOR return lines. It does matter if you get bubbles coming out of the IP being returned to the tank. Clear 1/4 line from the top of the Injection Pump to the return fuel rail.

2 PSI idle means your lift pump is shot or you have a restriction. But, check voltage at the pump with the pump connected and running as the OPS or relay may be failing and not passing enough current to run the pump. For example 7 volts means you have a problem that isn't solely with the pump. (Relay or OPS depends on year.) This low pressure will cause hard starting. I can't recommend a Walbro FRB5 enough over the junk factory lift pumps because I hate taking diesel/biodiesel baths changing them out so often.

 

[ak diesel driver]

ops isn't an issue for him

 

[JMJNet]

He already changed the LP with 93. He said it after the mileage line.

I suspect, the tank sock is clogging? Most probably cause.

Also check the bottom of the fuel filter housing. The o-ring of the heater may be leaking.
Leak is difficult to see since it is buried on the back behind the manifold.

 

[swany211501]

Easy ones first. My ffm has zero leaks. Lift punp was changed in November to a replacement OEM for a 93. I will be changing all the fuel lines for piece of mind, also to incorperate my Stewart Warner pump. The fittings are npt thread so I will just remove the old lines instead of hacking them to bits trying to bastardize it. Now, the return lines off my injectors tee together with the return line off the injection pump which led me to believe same return line. That was the only reason for that. I just did the home made turbo master with a piece of 1/4" ready rod and a 5/8's spring 2 3/4" long .074 thickness. I'm getting a small puff of black when I mash the throttle but clears up and I have an average 9-10 lbs boost and 2-3 cruising. Used a 100.5" belt.

So I'm away from home for a week. Keep the ideas coming. If its parts related, that's good because where I'm headed for work parts are cheaper then at home. I'm actually heading to Calgary if any members know where a wrecker with some 6.5's are PM me.

Also I got my hands on a 98 K47 box with the MAF sensor. What is recommnended for intake tubing? Just abs pipe? I measured 3" and figured I needed a street *90, regular 90 and a 3" rubber coupler. Let me know if there is something better to use.

Frank

 

[WarWagon]

I agree to check other things for low lift pump pressure. However, new parts do not mean you solved the problem - if I changed the lift pump in November it would be due for second factory lift pump replacement since then... Check your local laws on diesel fuel as some states require biodiesel to be blended in and bio eats the valves out of the factory lift pumps quickly.

If you have bubbles out of the IP return hose that could be the cause of low lift pump pressure - sucking air.

Do you have a tune to handle the homemade TM? Otherwise you can de-fuel from high IAT and boost.

 

[swany211501]

Funny you mention defueling. I freshly install it and my tri pillar and take it for a rip. Boost set to peak at 12 lbs. Deciding since I have an eye on things now, I should see what I gained by the seat of your pants test. I'm just rolling coal being very proud of the boost and the peppy feel and it was like hitting the speed limiter in a gas job. So I threw the brick on it, cleared the codes and turned the boost down to peak at 9-10. I'm going right by Lyndon's on the way to Calgary so I might pick up an ecm from him.
I always suspected the lift pump being either faulty or having holes in the lines after reading various threads about the troubles others had. Now that it is nice outside it's not so hard to work on my truck.
I love Canada for our lack of by laws and emitions regulations. I don't run bio though. When I buy diesel in ND I get #2 because I don't know what bio does. Now I know and I won't be running it. The PO is a farmer and judging from the inside of the ffm he didn't run dyed fuel either.

What is needed to drop the tank? I have a motorcycle jack that would work great to stabilize the tank. Can I get it low enough after I undo the 3 screws that hold the filler tube on to unhook the sender and lines? Loosening the straps, what's the chances I will open up a bunch of pin holes on the tank? It's not like the east coast with salt. worst this truck seen was 15 years of gravel roads. What other hoses should I change? What are the id's of the hoses? Supply I was going 3/8" all the way. Those plastic lines that tee everything in on the front like injector return tied to IP return do they fail?

Thanks

Frank

 

[WarWagon]

If you replace the fuel pump with a Bio compatible one and replace the hoses at the back of the engine you will be fine in a bio mixture. Too cold to run it straight up in your area.