Cold starting woes...

[Qwazert]

So here's the "problem"...well, not really a problem because she still starts and runs...but there's a few gremlins in there and I'm just curious if they're the norm or if something's wrong.

Summer starts were easy...no problem at all, other than maybe a tiny bit of white smoke if she hadn't been started in a few days.

Now that winter's coming, the cold starts are a bit more dramatic. I've read about cycling the GPR a few times before cranking over, and I do that. There's a BIG cloud of white smoke that disappears in less than a minute.
While she's sitting at idle, the engine RPM's pick up and drop off, and the DRL's seem to brighten and darken according to the RPMs.
If I give her a bit of pedal to increase the RPM's...the DRL's and dashlights really act up - getting brighter and darker...hi and low!
After the GPR has timed out and turns off, everything settles down and acts normally.
Is this indicative of a GPR that is slowly frying? It seems as though the lights are responding to an increase and decrease in battery draw, but the only thing drawing on the battery is the glow plugs...why else would the GPR be turning them on and off, unless it was burning out?
Does this make sense?
Did I answer my own question?
I will be picking up a new GPR this weekend, just a standard one since this one has lasted 172,000 km and I doubt if I'll put as many more on.
Has anyone else ever noticed this sort of phenomena? It's strange!

[desertdeer]

its normal. the surging is the glowplugs cycling on and off. usually lasts a couple minutes and then goes away.

glow plugs keep heating even after the motor is started

[backwoodsboy]

Glow plug duration is dependent on quite a few parameters, and they will continue to cycle once the engine is started.
Everything you are experiencing is completely normal.
If you are stuck on getting a new relay, check out the 56131K relay from Western Plow. Cheap and seems to last on par with the Stancor.
http://www.russopower.com/products/w...lenoid-56131k/

[madpogue]

What you read about "cycling" the glow plugs is wrong. You DON'T "cycle" them. As said above, they stay on after the WTS light goes off. If you need more glow plug time, just leave the key in RUN for a longer time.

And the surging with the glow plugs cycling on their own is NOT normal. That's def. a sign of something wrong. The glow plugs come on when you turn the key to RUN, and run for up to two minues, and then shut off, and that's it. If they're cycling on their own, something else is going on. The alternator and/or batteries are weak, or the relay is failing, or the glow plugs are pulling too much power.

And the GPR is far from the only thing drawing power. Obviously the DRLs are on, and the PCM and IDM draw power. Dunno if this would make any difference, but the parking brake turns off the DRLs, correct? If so, keep it engaged so as to keep the DRLs off, just to see if it makes a difference. Not expecting it would, but just to rule it out.

[Qwazert]

Well...now I am totally confused.

It's normal...it's NOT normal...I am back where I started!

[rolsmojave3]

All of the 7.3s I've worked on cycle the glow plugs after starting. Some trucks with weaker batterys/poor cables & connections show this more. I turn my key to "On" and let the GP's warm for about a minute, then I fire it up.

[jesilvas]

The gpr will stay engaged for up to almost two minutes. Don't cycle it until then.
Now, the gpr should not cycle like that while running. Should be constant.
Check your batteries, alternator, and connections.

I made my Samsung SGH-I997 send this.

[madpogue]

If they turn off, and turn on again, that's a problem. Doesn't matter how common it is, it's a problem. The PCM simply isn't programmed to do that.

And yes, the GPs will run after starting, since they're there to heat the combustion chambers while running cold. But again, they should run solid until the PCM turns off the relay, and that should be it.

[Qwazert]

Well, I changed the GPR out today with a BRAND NEW BWD GPR11 from O'Reilly's. Is roughly the same size as the stock offering.
Didn't make a bit of difference...still smokes for the first 10 or 15 seconds, then clears up. As for the turning on and off...I can't say for sure that's what happens, but the battery guage jumps around a bit, a few times before the GPR relay turns off for good.
Not sure what is causing the modulating...

Looks like I'll be plugging her in until Spring...

[jesilvas]

Is the gpr working properly?
Uvch and connections good?
GPs good?

I made my Samsung SGH-I997 send this.