Truck starts great inside, like crap outside??

[cwlehner]

This sounds crazy, but I figured someone might know why it is happening..

The weather in Michigan has got pretty cold this last week, but as long as my truck is parked inside it starts great. It started almost instantly this morning after being parked for 14 hours and the inside temp of my barn was 18F (truck not plugged in). This has been the story every day for the last week.

Now for the confusing part. It only starts after the third try when sitting in the parking lot at work for about 10 hours with temps as high as 40F!! It has done it consistantly lately (all on the same tank of fuel). It hasn't failed me yet, but it is making me nervous..

I have Kennedy quick heats, resistor mod to extend the glow cycle, Rotella Synthetic, battery connector mods, etc...

The only thing I can think of is my glow plug connectors since the problem seems to be somewhat related to precipitation. They aren't factory original and if I wiggle them, it seems to start quicker.. Is it possible that the current is not able to transfer through them as well due to moisture build up or something like that? Would anyone recommend putting a dab of grease on the connections (I just dont want it to melt and short the plug out)..

Maybe I'm off of my rocker, any ideas would be appreciated!

Thanks!!

[cwlehner]

same scenario all week... inside starts are great, outside starts make me wonder when I'm going to get stranded...

31 looks and no replies makes me think i have an enigma on my hands...

Thanks anyway!

Chad

[moondoggie]

Good Day!

parked inside it starts great
only starts after the third try when sitting in the parking lot at work for about 10 hours with temps as high as 40F
glow plug connectors...if I wiggle them, it seems to start quicker
How long have you had this truck?
Is this a problem that has suddenly appeared?
Does it make white smoke on start-up?
If so, how much?
How does it run otherwise:
-----cold
-----warming up
-----fully warmed up
How does it start after reaching full operating temp, then shut down for only a few minutes?

Since you've only mentioned glow plugs, we can discuss that. The difficulty of determining if you have bad glow plug connections is that as soon as you touch anything, you've affected it, killing troubleshooting efforts.

A quick test would be to measure the voltage across the glow plug relay while someone else turns your key to "run" (NOT "crank"). Any voltage here WHILE THE GLOW PLUG RELAY IS ACTIVATED can only be due to glow plug relay contacts that are showing wear. I have now idea how much voltage drop is too much, but certainly it should be < 0.5V.

"...my glow plug connectors...aren't factory original..." This might be the best place to start. Radio Shack connectors aren't made of the same stuff as automotive non-sealed under-hood connectors. Swallow hard & go buy the replacement pigtails they sell at the dealer. Then clip off your present connectors & either solder the new pigtails on, or use a heat-shrink-sealed butt splice (http://www.mpja.com/listitems.asp?dept=96&main=83) (Click in colored text) (scroll down to "Heat Shrink Insulated Butt Splices"), which will be as good as soldering.

If I were stuck in your situation & wanted to troubleshoot to verify where the problem really is (assuming the glow plugs have anything to do with it), I'd verify with Kennedy that really long glow times won't burn out the glow plugs. (If memory serves, these can be left on at full voltage (12V) & won't burn out, but make sure of this 1st.) Then I'd find a way to measure glow plug current draw. It's a LOT of current - I think all 8 can draw as much as 150A, at least initially. You used to be able to buy an ammeter that simply sat on the wire - somehow or other the magnetic field caused by the current flow moved the ammeter's needle. Or, an appropriate shunt can be purchased, allowing any DVM to measure the voltage across the shunt, which will be some small fraction (.001X or such) of the current flowing.

Either meter can be used on the fat wire coming out of the driver-side battery - > 99% of the current through this wire will be going to the glow plugs.

Then I'd short across the glow plug relay, monitor the ammeter, & start wiggling stuff. If you wiggle a glow plug connector & the current increases, you just found a connection that had been bad.

Let us know what you come up with. I can't follow up with you myself this weekend - my only I'net access is at work.

Blessings!

[gmctd]

Is the parking lot at an angle, where the truck is nose up?

Or is inside angled where the nose is down?

[cwlehner]

Hey Moondoggie,

I appreciate all the help. Sorry about the delay in my response, came down with Bronchitis and am now felling good enough to work on it..

Anyway, to answer your questions.

>How long have you had this truck?

1.5 years

>Is this a problem that has suddenly appeared?

difficult to answer since I have done so many glow system mods. A year ago it was impossible to start cold. GC resistor mod + synthetic oil + battery terminal mods + kennedy Quick Heats improved most of the starts drastically.

>Does it make white smoke on start-up?

Generally on the good starts there isn't a lot of white smoke, the bad starts have a bit (not a huge cloud, but enough to make the non-Diesel crowd stare)

>If so, how much?

Worst case is a cloud the size of my truck.


>How does it run otherwise:
>-----cold
>-----warming up
>-----fully warmed up

Once it starts, it always runs great.

>How does it start after reaching full operating temp, then shut down for only >a few minutes?

Above ~ 40F it starts instantaneously (<1 sec).
Below it may take 2-5 seconds of cranking. I put a temp inhibit switch bypass on it which also starts it instantly.

I went with your first suggestion and tried to get GP connector pigtales. They couldn't come up with a part number. The guy was kind enough to give me a bunch of the Generic Radio Shack style connectors, but I am hoping to get factory originals. Anyone have an idea on part numbers??

Thanks!

Also gmtcd, the truck is always parked level.

Thanks!

[gmctd]

The level stance eliminates a fuel drain-back scenario.

Use a dull pair of dikes to slightly 'crimp' the edges of the female spade connectors - gives positive electrical connection.

Try a cold-start.

Then, pull the ECT sensor connector, try a cold-start, noting the results - gives extended glow duration, greater advance.

May DTC, but not to worry - it's the results we're after.

[moondoggie]

Good Day!

Based on all your answers, I'd still try to get factory pigtails. I though I'd read of others here on the Page doing this, so I'm guessing the dealer can get these, but that's from memory (always suspect), plus your dealer's parts guys have gotta care enough to dig. My closest dealer's parts dept. is a joke - if they gotta get out of their chair or click their 'puter more than a couple times, they'll just tell you it doesn't exist; others in my area are WAY helpful.

I'd also consider the glow current test I described.

I'm thinking now that maybe your best bet might be to search & find the FSD power mod someone described. Basically, the mod involves powering the FSD through a relay that's powered through the ignition switch. So, the ignition switch powers the relay, which powers the FSD through MUCH bigger wire. A 2nd member did this mod & found additional benefits to this mod. If/when I ever do mine, I'm gonna ground the FSD right to the IM with big wire too.





Blessings!
(signature in previous post)

[arveetek]

Good Day!

I'm thinking now that maybe your best bet might be to search & find the FSD power mod someone described. Basically, the mod involves powering the FSD through a relay that's powered through the ignition switch. So, the ignition switch powers the relay, which powers the FSD through MUCH bigger wire. A 2nd member did this mod & found additional benefits to this mod. If/when I ever do mine, I'm gonna ground the FSD right to the IM with big wire too.



Don't forget, moondoggie, that his 6.2L doesn't have an FSD! Another great benefit of an old 6.2L.

Casey

[moondoggie]

Good Day!

Isn't the Page great? Not only am I a moron, but ~ 20,000 people get to read the proof. :rolleyes:

Blessings!

(signature in previous post)

[arveetek]

Good Day!

Isn't the Page great? Not only am I a moron, but ~ 20,000 people get to read the proof. :rolleyes:

Blessings!

(signature in previous post)

Oh moonie baby, you ain't a moron! Not in the least. You just forgot, that's all! :D Happens to the best of us!

Casey

[N9Phil]

Have you noticed any fuel leaks. I had a similar problem with my 88 6.2 in the last year and it ended up being a leaking fuel line. a believe a bad fuel cap can also and cause starting problems.

N9Phil

[gmctd]

Well, looks like I'm in that same spotlit area with moon-doggie - pulling your ECT, or HPCA, will disable cold-advance.

But it is possible that the HPCA sensor - which is a thermo-switch - is bad.

Pull the connector, put a jumper across the connector terminals, try a cold-start - if that works, replace the sensor.

If not, possibly the HPCA solenoid in the Inj Pump is bad - on passenger-side side of IP - jumper it to +12v, should click slightly if good