smokey haze

[Drillman]

One issue driving me to distraction.
1997 sierra 2500 6.5ltr 320000kms, cold start results in coughing and sputtering and a thick haze of white smoke for 15 to 20 seconds then smooths out and all good. Not hard to start, just a couple of cranks and away it goes, just runs like a dog.
Replaced lift pump (wiring all good )
Replaced fuel filter
New injectors
New glow plugs (again wiring all good)
No obvious fuel leaks
Compression test came up all good

Getting embarrassing in public (try to be the last to leave the rodeo, hard when you're trying to get to the next one)
Where to look and what to do next, please.:(

Remote PMD, #9 resistor, new GM8 turbo, manual waste gate, 2.5" cross pipe, 3" dump chamber, 4" turbo back exhaust

[a5150nut]

Bout the only thing left is air filter.

[Drillman]

Thinking air filter would result in black smoke. Not enough air in the mix .
What's the odds that fuel can bleed back overnight causing a push of air in the fuel at start up.
Am I on the right track thinking that this could be the issue?

[DmaxMaverick]

Welcome aboard!


Thinking air filter would result in black smoke. Not enough air in the mix .

Correct. Black smoke, among other symptoms.


What's the odds that fuel can bleed back overnight causing a push of air in the fuel at start up. Am I on the right track thinking that this could be the issue?Yes. This is quite common, especially on older (well used) vehicles, for a number of possible causes.

The first thing to do (unless already done), is replace the fuel filler cap. Make sure it is a "Diesel Fuel Only" cap, usually green in color these days. The gasser cap doesn't vent correctly (and will cause air-in-fuel problems). The Diesel caps vent in both directions to prevent excess system pressure or vacuum, due to (among others) expansion and contraction with temperature changes (day/running/heating to night/idle/cooling). Similarly, a Diesel cap won't work on a gasser, due to the venting. A (1990+ for many, 1996+ for most) gasser with a Diesel cap will have emission system fault issues.

If this simple step doesn't fix it, you'll have to begin diagnostics to look for the leak that's allowing air into the system. Any "wet" spots would be a first indicator, but not all leaks that allow air in, will allow fuel out (such as the fuel manager/filter or any quick-connectors).

[Drillman]

Thanks for the feedback
Next step is going to be inlet manifold off to start working back from IP through to tank.
Would this also cause power loss when out of boost range ?
Another issue but started at same time.

[DmaxMaverick]

If you are having a fuel leak or air related power loss, it may be better starting at the tank, then moving forward. The fuel lift pump will normally overcome any pressurized leaks (between the LP and IP), while prior to the LP, air will continue to leak in. Although, leaks prior to the LP won't normally cause only starting issues, and usually continues after warm up. Loss of power once up to operating temp may or may not be related, but less likely if the condition clears up rather quickly (less than a minute or so).

Also consider fuel quality/contamination. Enough petrol in the mix can (and does) cause exactly what you describe. More than about 20% petrol will cause cold starting issues, and more than about 15% will cause noticeable power loss. 10% petrol with #2 Diesel is comparable to straight #1 Diesel, in regards to cold starting and power, and quality decreases as the concentration increases. While lower concentrations aren't harmful, higher concentrations can cause long-term serious issues.

[Drillman]

Think I may just replace all lines from one end to the other to rule this one out.
I'll let you know in a couple of days how I got on.

[DmaxMaverick]

That's one way to do it. Good luck!

I generally don't like to throw parts at a problem, but considering the age it's probably due or close to it, anyway.

[Drillman]

Okay so that didn't fix it.
Next step? PMD or pump?
Possible that PMD playing up and not advancing timing when required?

[DmaxMaverick]

The PMD has nothing to do with timing. It' s a slave, and rarely has issues that don't continue after a successful start. The pump however, also a slave controlled by the PCM, does.

Verify the presence/absence of air in the system at the time of a start. If no air and the condition persists, the injection pump is suspect. Still, fuel quality is also suspect.

[Drillman]

Fuel quality is fine and I have run a sight glass in the line with no signs of air at all.
Pity I was hoping it would be that easy.
Looks like the pump may be my issue then, at about $3k over here I've been trying to avoid that one.
I'll keep you posted on the results as I go.

[DmaxMaverick]

$3K USD? Wow. How much would it cost to ship it? Rebuilds and reman's can be had for less than 1/2 that. Many suppliers ship international, as well. For example, Kennedy (http://www.kennedydiesel.com/categoryresults3.cfm?Category=1&SubCategory=159&SubCategory2=101) offers a NEW 5521 pump for less than $1300. Reman's are less than that, but require a core return.

[Drillman]

Sorry I should have clarified that one, I'm in Australia so in AU dollars.
Most places seem to want about $200 for freight from US but even with exchange rate Kennedy or SS diesel are looking good.
Given that this may be a timing issue (not advancing when required, may explain the power loss as well as the cold start smoke)what are the odds it could just be the stepper motor shot?

[DmaxMaverick]

It could be just the stepper. But on a high mileage pump, it's just the first failure of many to follow, hystorically. I wouldn't mess with it. I recommend sending messages to the suppliers you mentioned and see what they can do for you. Then there's ebay, but be very careful there.

[Robyn]

Thinking about this one.

White smoke at start up only with some missing and such, then fine.

This points to either a glow plug issue or some injectors that are not squirting right.

You mentioned new glow plugs ??? Which ones are installed?? AC DELCO 60G is the best choice

Do all plugs get a good 12Volts when the relay is powered on???

Make sure the plugs all get Red, especially at the tip

A couple plugs not working will cause the white smoke at start up.

You could have an issue with a couple glow plug wires.
Check each wire with a meter to be sure they are getting power.

These wires are all "Fusable" and can melt internally if there has been a problem at some time.

You mentioned New injectors ???

Were these brand new, or remans??? Source ???

If these were remans I am suspicious.

Poor pop pressure on a couple injectors can cause a real smoke job.

They should pop around 2000 to 2200 psi

Get down in the 1500 or lower with a sloppy squirt and the beast will smoke real bad til it warms up.


The fact that it runs fine after a few minutes makes me think it has nothing to do with the IP

The other possibility is AIR in the system after sitting over night.

Get a clear plastic tube and connect between the return from the IP and the hose and loop it by the wipers so you can watch it.

Streams of bubbles are bad ju ju


Normally a bad IP with enough issues to cause smoke and such will set a code or the issues will continue even after start up.


Check it out

Keep us in the loop mate

Missy

[Drillman]

Hey Missy
They were new injectors and not sure now what brand of glows.
Problem was there first hence doing the injector / glow change, most obvious issue. Power to glows comes up fine and have done the sight glass in the line trick with no air showing.
Issue just came out of nowhere, all running fine then thick fog on start up and noticable power loss below boost range. Researching the hell out of it from here in Aus I'm starting to lean toward a timing problem, supposedly the pump advances for cold start and I'm guessing at other times when driving. No advance on cold start would give the smoking, hoping the power loss below boost is related so I can fix both problems at once.
Purchased this truck for towing 10,000lb 5th wheel horse trailer, went well for first run of 2300kms then this problem started and been a money pit since.
Missed the finals with the truck in pieces so not giving warm fuzzy feelings just yet.

[DmaxMaverick]

Does this truck have a catalytic converter and/or EGR? What's the 8th digit of the VIN?

[Drillman]

No CAT and you've lost me on the EGR so I'll say no to that as well.
8th digit on the VIN is F
In the process of removing the IP we've found the timing chain to be worn and has a lot of slack so again leading to a timing issue. Manually advanced the pump and everything sharper with only a small amount of smoke at startup which I can live with if I have to. Going to bench test the IP seeing as things are this far along so see where it goes from here.

[DmaxMaverick]

EGR = Exhaust Gas Recirculation (more smog stuff). VIN F shouldn't have cat or EGR, but strange combinations happen, especially with exports.

A worn timing chain rarely has much affect on the EFI engines, unless the IP near it's useful life. What will happen with a loose chain is, the pump will have issues compensating, code faults, and revert to default fueling. Manually advancing the pump only varies the TDCO, which will physically limit the timing window it is able to electronically adjust (prevents excessive retarding). Ultimately, the loose chain will see it cross the acceptable limit, and it will code more faults which typically cause it to go in and out of default, and ultimately limp mode. The end result is a worn-out IP, getting more worn as the miles pass. If the pump and chain are original, they are both past-due at 320,000 Km, in any case.

[Drillman]

Okay after a bit of a break (work got in the way of play)
IP bench tested and though not shot yet it is well on its way. Replacement sourced locally range $2300 to $3000 Aus dollars, so importing is the answer.
SS diesel has good pricing but freight charges are a bit extreme.
What sort of reputation does Pensacola Diesel have ?
Is there anywhere else I should be looking ?

[trbankii]

Check with John Kennedy with Kennedy Diesel - in the advertiser’s section here. He lists remanufactured electronic IPs for just over $1K US (about $1500 for you, if I’m figuring correctly). I can’t believe that shipping would be so expensive that it would put you in the range you’re quoting.

[svcattle]

One issue driving me to distraction.
1997 sierra 2500 6.5ltr 320000kms, cold start results in coughing and sputtering and a thick haze of white smoke for 15 to 20 seconds then smooths out and all good. Not hard to start, just a couple of cranks and away it goes, just runs like a dog.
Replaced lift pump (wiring all good )
Replaced fuel filter
New injectors
New glow plugs (again wiring all good)
No obvious fuel leaks
Compression test came up all good

Getting embarrassing in public (try to be the last to leave the rodeo, hard when you're trying to get to the next one)
Where to look and what to do next, please.:(

Remote PMD, #9 resistor, new GM8 turbo, manual waste gate, 2.5" cross pipe, 3" dump chamber, 4" turbo back exhaust

mine does this to but if i give it 1/4 throttle it starts right up no smoke

[rapidoxidationman]

Electronic throttle (fly by wire) means your fuel pedal is ignored until it starts, IIRC. You could hold it to the floor and it won't do anything until the computer says it can.

[svcattle]

i dont know much about these trucks but i do know it makes a big difference to give my truck a little bit of throttle when starting

[Kennedy]

During my early years of 6.5 ownership my '96 was under factory warranty. I had the pump replaced 4 times in one summer. It did the poor start, smoked white, chugged, missed, etc.

Later there was the "cold glow plugs" deal with the old 11g. Shortly after that we started offering parts like the QH plugs and never had an issue since.

Pensacola is a 4 letter word.

I have numerous customers in Australia. Just drop me an email and I can do references.

[Drillman]

Finally back from the rigs and in civilization.
Results are:
Tested everything testable.
Replaced timing chain and gears
Replaced injection pump
All good now and picking it up today, expensive little toy but hoping for some trouble free running for a while.