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Glow Plugs not heating up?

treegump

treegump

Romans 3:22-24
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Location
Martinsville, IN
Has anyone ever experienced their glow plugs not heating up all the way? I only ask because I leave my glow plug override on for about 30-35 seconds and I get the same 3 or 4 turn overs before it starts, as if it were 70 degrees out (which is still wrong - I'm just saying).

Sometimes I hear a faint whirring noise that sounds like its coming from the other side of the fire wall - can you guys hear your glow plug...solenoid/controller? Also, if the engine is hot and I shut it off and immediately turn it back on, it'll usually start with no problems - but that's the only time!

I still have the injectors to change - not new - but they sure look like it. Changed the older starter for a cleaner used starter - so I suppose it could be the starter...but I really don't think so.

(side note - I love this warmer weather (35*) - I can tell in my fuel flow=acceleration (it seems like it anyways...))
 
540s10 said:
check for air in the filter manager.
Click to expand...

um...well, would i do that just by loosening the manager's lid until fuel came out and then tighten it? If that's the case...I think I've already done that. And I'm about 6k on my fuel filter, but even with a new fuel filter, that's how it starts.
 
with the lift pump on open the bleed screw on top of the filter until its fuel with no bubbles... mine was doing what you're describing and after I got the little bit of air out of the filter it started as it should.

Is it firing at all when your cranking it at first or is it cranking and then just all of a sudden all the cylinders catch?

and when it starts is it nice and smooth or rough for a few seconds?
 
Depends on what kind of GP? some GP will melt/burnt and some GP won't lit for 35 sec.

I agree with LP may not function, do a proper test. There is a procedure in the FAQ on how to do it.
 
If you figure your plugs are actin' up then I'd start with them. Figure out what type you have, check'em all for power, make sure they all are workin', etc.. Usin' an over ride for 30 secs on the wrong plug will kill'em. Then do lift pump tests and check for air.

Like 540s10, I'm curious how it acts when startin'? Is there much smoke, what colour, etc.. Need more info. Do the checklist!
 
I should have just continued this in this thread - sorry... (if there's a moderator that can do that - that'd be terrific!)

http://www.thetruckstop.us/forum/showthread.php?t=18405

edit: I unscrewed the filter manager and did what you said and it started alot better the next morning. After I turned it off at work and tried starting it after about 2 hrs or so, it went back to what the video sounded like. My GP's are ac delco 60's ? (the good ones - and I just replaced all of them no more than 12k miles ago) The coolant leak (as described on there..maybe) - its fixed - it was the quick disconnect. And as heard on the on the video - this is how its always started. I showed normal fuel pressure last time I checked with the fuel pressure gauge, and as far as I know, I've checked (and retapped/rewired) all the grounds. The batteries show good, and have good connections. And as you can hear in the video - its runs rough for a few seconds.

I guess a couple of questions:

1) can air get in the filter manager somehow, so that whenever I shut it off, air gets in?
2) how do I test my glow plugs without burning myself or frying my voltmeter
 
treegump said:
I should have just continued this in this thread - sorry... (if there's a moderator that can do that - that'd be terrific!)

http://www.thetruckstop.us/forum/showthread.php?t=18405

edit: I unscrewed the filter manager and did what you said and it started alot better the next morning. After I turned it off at work and tried starting it after about 2 hrs or so, it went back to what the video sounded like. My GP's are ac delco 60's ? (the good ones - and I just replaced all of them no more than 12k miles ago) The coolant leak (as described on there..maybe) - its fixed - it was the quick disconnect. And as heard on the on the video - this is how its always started. I showed normal fuel pressure last time I checked with the fuel pressure gauge, and as far as I know, I've checked (and retapped/rewired) all the grounds. The batteries show good, and have good connections. And as you can hear in the video - its runs rough for a few seconds.

I guess a couple of questions:

1) can air get in the filter manager somehow, so that whenever I shut it off, air gets in?
2) how do I test my glow plugs without burning myself or frying my voltmeter
Click to expand...

it sounds like a fuel issue more so than a glow plug issue

air can get in the filter manager via a worn oring on the filter, or a tiny pinhole in the line.

My issue was a rotted sending unit and a rotted line into the lift pump, it would suck up a little air in the fuel and once it made its way into the filter all the air accumulates at the top.. It doesnt take much air to affect things because the injection pump takes its fuel near the top of the filter manager.

this can also happen if you run the tank low and suck up some foamy fuel while goin up or down hills.

you can check the glow plugs just by taking them out and connecting them to a battery, they should get about 1/2 red by 15 seconds and fully glowing red by 30.
 
Ok - that gives me a few more things to try. I guess when I asked how to test the plugs...I meant, how do I test the end of the wire - that connects to the GP? I was just wondering if there is power getting to the GP. Also - I hear a faint whirring on the other side of the firewall...when I'm sitting in the driver's seat...but its very infrequent. When ya'll start your truck...do you hear something whirring on the other side of the firewall...and any ideas as to what it is, and if I should really hear, and if it should be continuous.
 
you should be able hear the lift pump working, if there is any air, it will be loud for a second and then quieter. when the lines are all full of fuel it will be much quieter.
 
well, as i said in the first thread - i can hear my pump clicking under me - up until the factory GP setting stops - then the pump stops clicking. Oh...is there a pump in the filter manager??? that would be whirring?
 
NO pump in the filter manager,,, that wiring sound you hear is probaly a electrical noise, from the glow controller. Just cause you hear it, don't mean its pumping, at full shot. You really need to test the pressure, with it at full throttle to see if it's up to snuff. If you need to replace it, get a unit for a 93 truck.
I've also been told you can test the glows for dead ones, by using a 12V tester, hooked to the Pos bat,, then touch the unpluged glow terminal. If it lights up, it's good. Never done this,, but it sounded easier then pulling all the glows. Also the glow wire should light up the tester if it's grounded, and you have someone hit the key for you to cycle the glows, More of a 4 handed test. =)
 
Hey Forest, when it's cold out, my truck always has to crank a few times before starting. To me it's just normal. As for the noise you're hearing, could be your alt. because you had your override on for 35 sec's.

Just my take on it.
 
Last edited:
Noise could be the blower motor or a HVAC door. Could also be morning sickness on the cooling fan clutch - normal till it kicks out.

Change the injectors already. Rough running and stalling were cured with mine being replaced.

If you are spinning the engine and then it comes to life. You glow plug light is not on. The spinning engine helps cool them off. So back to fuel issue. Injectors or air in the system as noted above.
 
Well, with any self regulating glow plug, what happens when it gets to a point when it is self regulating? Is it maintaining its max glow or does it start to limit its glow?

There must be a point at which more Glow doesnt help and is only detrimental. If they are fully heated at 20 seconds, no need to keep em on.

What are the best glow plugs anyway? Is there something more reliable than 60Gs?
 
The truck stalled for the first time this morning, but had no issues after I switched the high idle on. I'm going to try and change injectors this weekend, and I'm planning on changing the fuel filter sometime this week - has 8k on it...maybe? I haven't checked the air filter lately either - so gonna check that too. The LP is clicking while the engine is running - but you're saying that doesn't necessarily mean anything? I haven't noticed anything different in the running of the truck since I bought it - everything is the same...but I've always had this issue with starting it. I'm getting low 13's mpg with my heavy foot and empty load, and high 13's (or better) with a full load of firewood. I have no reason to suspect that my fuel pressure has dropped - but then again when I checked/recorded it the first time - I had it attached to the "T" valve at the front of the engine and not the fuel line between the manager and the "T" which I should have...I guess. (Need to search what I need to do that with). Thanks everyone for all the help!! Much appreciated!
 
after checking here - http://www.thetruckstop.us/forum/showthread.php?t=2647 . I have a question...
I know that when I open up the T valve or the plastic valve on top of the manager, I get a good flow of fuel. I also know that when my truck is at WTS and running, my fuel pump makes an audible clicking (you have to be within 6" of the pump to hear it after the motor turns on-nearly drowns it out).

I'll hook up the fuel pressure gauge back up, but since i have good flow from those 2 spots and I have not noticed any changes in my truck's performance, after the engine runs for a few minutes, should I still be concerned about the LP? According to the above article - clacking means it may be failing or has failed...but I have fuel flowing...so...

edit: fuel flows from those 2 points while engine is running
 
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