Cold (18F) startup question

[Mark Rinker]

One of my '94s with the '98 engine used to be the smoothest starter of the two. However, it now is very noisy, blue/white smoke, and you can hear cylinders 'coming online' as the truck rattles and bucks its way to warm operation.

The glowplugs connections were all recently cleaned and replaced. New batteries and starter last season, so plenty of power and crank time.

Q: Are there any other factors to consider here, other than the obvious replacement of all 8 glowplugs with brand new 9Gs?

You'd swear the thing was going to schuck a rod with the noise that comes from the engine during cold startup. Its terrible...

[gmctd]

Pull the ECT connector, see what transpires with longer glow, more advance, little more fuel for -40F scenario.

60G's are the plug of choice - they also fail eventually, but the tips don't swell up as part of the failure

The increased rattle is cold-advance - why I reset TDCO back to -1.5deg from -1.94deg.

The rough running is not enough heat for additional fuel at cold-advance

[Robyn]

Mark
How many miles on the squirts??
If they have some serious miles yank the squirts out and get them tested for pop pressure and spray.
What happens is the pop presure drops and the injectors squirt rather than mist and this is why all the rattling and missing. Once the engine gets some heat in it the injectors will work somewhat better and loosen up a little bit.
The pintle gets stuck and will either just pass the fuel at low pressure or the nozzle atomizer holes get fouled and the suckers will squirt off over into the corner.
With the cold the problem is made even worse. Glowing more may help as there is a reeeeeealy hot place for the fuel to ignite on but I dont believe this is the real fix. Have a look at the squirts. :0)
The 94 I rebuilt late spring really rattles to life with gusto now that it has a new set of injectors in it.
Just a thought.
Robyn

[ronniejoe]

Have you checked each individual glow plug to ensure that they're all working. A dead one here and there will cause symptoms like what you describe.

[Mark Rinker]

I don't know the injector history of the used replacement engine, but would guess that the original injectors were still in at 58K. I have another 32K on the motor now, so would say they have 90K on them.

Once warm, the truck runs fine with plenty of power. Its simply the rough running at cold startup I described which is 'new' to this truck this season. The truck has spent alot of time sitting during the off season, so will run a few tanks of fresh fuel through, with plenty of additive to clean things up before tearing into it.

If I replace glows, I'll replace the 'squirts' at the same time with a set of hi-pops. Will look into timing at that time as well. Should have done all this at the time of the motor swap, but had already spent enough $$$ with the engine, oil cooler modifications, batteries, etc...

Thanks for the ideas - chances are that this will come around in mid January when things get REALLY cold. In the meantime, I'll make sure this truck stays plugged in any time the snow is coming, regardless of temperature.

[Dvldog8793]

Howdy
My truck started doing the same thing this year, EXACTLY the same thing. I attributed it to weaker injectors and SLSDfuel. I think a combination of the new fuel, weak injectors, and the real cold does it. It just seems to run in a kind of "funk" mode for about 15-30 seconds. SEEMS like forever cause it sounds like the world is ending! LOTS of smoke. Anyways, if I keep her plugged in, no FUNK-time, If I double up on additive(FPPF) no FUNK-time. it will be about 0* here tonight so my rig will be plugged in. I'll tell you what happens in the AM.
L8r
Conley(up in Grand Rapids MN)

[damork]

9G glow plugs should not be used - they are problematic with swelling tips. I replaced my 9Gs at 76k with 60Gs, and just did it again at 238k. The 60Gs came out with no problem, some were definitely dead.

My injectors might need replacement @162k on them, but the new glow plugs AND a new glow plug relay make it pop to life on all 8 without the usual blubbering around that misfires cause. I think the Stanadyne blue has kept my injectors clean as it still starts well when cold and ecomony has not changed (18-19 mpg @ 60).

I think that a new glow plug relay should be included whenever installing new glow plugs. I've taken my old ones apart and based on the contacts inside them they were due for a change.

[tommac95]

I'd vote -
1) Fuel (additives+)
2) Glowplug check current to all ; ECT ; relay.
3) Injectors

Thanks for the GP relay forensics to Damork. If original relay probly time for renew.

[Dvldog8793]

OK-
Last night I had to start the rig after sitting(not plugged in) for 8 hours in about 0*, Same bad FUNK symptoms for about 20seconds. I added another dose of additive. This morning the truck was plugged in with similar temps, I started it and only about 2 seconds of FUNK, and then a nice idle. Last night I also talked to a couple of trusted diesel mechanics(amid poker and whiskey) and we decided that this problem was probably the result of the new fuel, aging injectors and the cold. Anyways, for my truck the answer seems to be keep it plugged in with good fuel.
Hope this helps!
L8r
Conley