So I havent had a chance to buy new Glow plugs nor do I even know how to test but here are my couple questions

1. Even with bad Glow plugs can a truck still start? And if so what the heck is making it fire? I have a feeling a couple still work because sometimes when its giving me a fit i feel what seems like the same cyliner or cylinders firing if that makes sense.

2. The cold has really kept my truck down all week and it seems the block heater is working but maybe not too full function? My windshield hasnt been icing over but at same time truck seems to still be cold and having hard start issues...

If I need plugs what all do I need to order up from ford? Plugs, Harness, gaskets?

If I wanted a fresh block heater what all is involved?

Truck has 254K and all this stuff is original

I did replace GPR myself I assume it doesnt go out within a month or two? or is that false assumption.

Some days this thing runs and some days not...I guess im a touch confused. Also when I smogged it the guy said I was running rich until He really layed into it on the dyno and he recommended a bg fuel system flush. Could I just be having starting issues because the fuel system is boogered up?

Advice...thanks guys. Springs around the corner and I would like to try and finally get the needed work done Ive just been too broke to fix this bas-terd

 

Ok to test you need an ohm meter, there are two plug-ins on each valve cover gasket that have 5 pins, the two on the outer edge are for the gps, the next to inner ones are for the injectors and the middle is a common ground. you need to ohm out the two outer plugs, if they are good they should ohm out to .1 to 7 ohms. if you have a bad one they will measure something like 560 or 1500 ohm etc, annything over 7 is bad. if you have 4 or more that are bad i would replace all 8, but thats just me some say do all 8 at the same time which is also a good idea instead of having to replace 3 or 4 at a time. and to answer your other questions

1. Yes your truck will start with a few bad gps but will have a hell of a time doing it, i had 4 bad ones when i did mine back in dec. and the truck would not like starting in anything under 40 degrees.

2. What makes you think your block heater isnt working? have you tested it yet? and if you look around you can find that a 6.0 block heater should work iirc but not sure. just search and ask around for buying a new one.

3.If you test your plugs and they are bad get new ones. are your gaskets leaking or damaged, if you think they are buy new ones if not they are re-usable gaskets so no problem just leaving them there, but just be aware around here they are about $75 a piece but i didnt know how old mine were so i replaced mine so i didnt have to go and take the vc's off again. and check your uvch (under valve cover harness) to see if its burnt up or damaged if so replace it, idk where to get it since i didnt do mine, but i got my gps and fel-pro gaskets from schucks. im sure you can get ur uvch from ford or another parts store.
I can not say this loud enough do not buy Autolite glowplugs or dorman gaskets(i think thats the name) they are both terrible products for our trucks, the autolite will swell up in the head when they go bad and break of when u try and replace them and the dorman gaskets have a tendancy to short out and make the gps seem like the are not working even if they are new. buy beru or motorcraft gps part number zd-11, napa or autozone dont cary them and look for fel-pro gaskets.

4. sometimes gpr's are fualty right out of the box so theres no garuntee there, if you never want to worry about your glow plug relay for a while buy a stancor relay. a few guys around here have had them for 5 or 6 years with no problem while others who buy regular ones have to replace them every year or 2.

good luck man.

 

Yes, it can start without glowplugs, but may start hard depending on how cold it is. You can use starting fluid BUT YOU MUST disable you GP system entirely by disconnecting the GPR (be careful of hot wires) or else bad things can happen.

Diesels fire using compression, the GP's are just used to cold start. Once the engine is running, the fuel is fired by the hot compressed air in the cylinders. Once the piston filled with hot compressed air reached TDC (or maybe a little before that?) the fuel is injected and the hot air ignites the atomized fuel and sends the piston back down.

With that kind of millage, I would hope the injectors have been rebuild or replaced, but if not that might contribute to some of the problems.... ALSO may want to pull the valve covers and check for burnt/bad connections

GP's can be tested but with that millage should be replaced, check this thread for more info https://www.ford-trucks.com/forums/4...ke-thread.html

You should check your resistance at the block heater plug, and at the connection at the block itself (right above the oil filter). Should be 12-15 Ohms. If your getting that at the element above the filter and not at the plug, your plug might be bad, and you can toss a new one on from a hardware or electrical store. Generally, the block heater itself doesn't go bad, it's just a lousy connection at the plug end

If all else fails, here is a link to a new kit
Ford 7.3 Powerstroke Diesel Block Heater Kit 1994-2003 - eBay (item 250771635323 end time Mar-12-11 09:52:39 PST)

Part numbers should be in that winter start thread mentioned above

What GPR did you replace it with? Many use an aftermarket GPR from Stancor p/n 802-586-902 586-902 Stancor General Purpose / Industrial Relays

Hope this helps some. At my lunch break now or else I would have written more. Others will chime in i'm sure. good luck

EDIT Blake, you type much faster than me man haha

 

Thanks for good response...I do plan on only buying ford glowplugs. Just bummed cause our Ford dealer in town sucks you know what. But I work at a Toyota dealer so maybe I can get them bought for whatever we get charged. With the high mileage im gonna guess the valve covers never been cracked so maybe gaskets would be smart. I have not intentions of doing the plugs myself. Is this a job straight forward enough for a Toyota mechanic to do? or am I gonna have to track down a diesel guy you think? Ive been thinking its the block heater but It appears glowplugs are the issue.

 

6 yrs on mine

 

I would do this yourslef its a good experience job for you to do. If you can turn a wrench, ratchet, screwdriver and spray some pb blaster you can do this job.
And rob, you know im tired of you always trying to one up me. Im just trying to help someone and you show me up once again haha jk man

 

your heater could be cracked and not working fully.


As for glow plugs, its a misconception that glow plugs are like spark plugs, Glow plugs only help increase cylinder temperature, they are not there to cause Ignition like a spark plug would.

 

Don't EVER EVER fall for that flushing anything scam on a diesel. BG ain't bad stuff but I would never put it in a diesel. Plus for the price of it they can throw in a free oil change. It would probably do more good. Really, don't let a shop flush anything on your truck. It's a scam.
Where do you live. Sounds like yours needs some attention. If you're near me I'd be happy to help out.

Oh and with any vehicle, but especially a diesel, before you get it smogged have the engine warmed all the way up. Preferrably rag the crap out of it for a few minutes before going on the machine. When you get to the shop, do not shut it off either till they are done. running rich my butt. That mechanic was having a slow week and obviously doesn't know squat about computer controlled diesels.

 

So the heat of the Glowplug itself does not ignite the fuel? I realize there is not an actual spark of course but always thought the glowplug assisted in igniting the fuel...But cylinder temperature does make sense. Do glowplugs turn off at a certain engine temp?

Thanks again everyone.

 

The glow plugs stay on depending on the starting temp of the engine.
like, for a cold start, they would stay on for 2 mins to help assist with cylinder tempatures and keep the smoke down

So if its cold out and your extra smokey, you could have UVCH or glow plug problems.
LIke me. I have all new stuff, and one of my connectors went kaput.

Heat + Pressure ignites the fuel. The cylidner temp has to be warm enough though, so thats what the glow plug helps with.

I'm pretty sure I've read a few people on here that actual fuel contact with the gp's creates something that isn't to good.

 

They are strictly a diesel shop and it was definately hot before I pulled up too them...It just smokes white alot on start up and smokes white when full throttling usually. Yesterday I actually got it to run and ran around the mountains for an hour to make sure it was "burnt Off" and then no start today. I remember i used to loose fuel filters on a Dmax I used to own and everyone said the biodiesel I ran (only couple times) would clear out a fuel system pretty good. Is b20 safe to run on these suckers to clean out injecters and lines? Ive been adding hows and some Power service hoping it would help and eliminate possible gelling...



ON a SIDE NOTE...my Front tank hasnt worked since I bought it. When I switch too front the gauge shows near empty and after a few minutes the motor starves out like its not getting any diesel EVEN THOUGH TANK IS FULL.

Is this the switch in dash or a valve gone bad or bad fuel pump?

Thanks again everyone

 

Do GPs actually thread into the cylinder like a spark plug? or do they just heat the metal in the head?

 

That would likely be in reference to the use of ether. Ether is far more flammable than diesel fuel and has a lower flash point (meaning it will explode at a lower temperature). Spraying ether into an engine with hot glow plugs can cause the ether to explode at the wrong time and seriously screw up the works! Most recommend that if you MUST use ether that you disconnect the glow plug relay or leave the ignition off for 5 minutes or so to ensure that the GPs cool off sufficiently before spraying in the starting fluid.

 

Howes sucks. I had a double dose of that stuff in my tank a few weeks ago and gelled solid at -2. I had powerservice in the tank before that, normal dose and -10 with no gel.
Anyway, Still no flush junk in a diesel. It's just bad news.

The glow plugs thread into the head like a spark plug. I think you need to look at all the connectors for them. If it's smoking white then some of them probably aren't working. The explanation how to check them is in a sticky at the top here. It's real easy if you have an ohm meter. The pins in the connectors get loose and burn sometimes. I had a couple last winter that were just too loose to work but they didn't melt the connector.
Testing the glow plugs is easy though. Read through that thread and you'll get it.

 

Schaeffers makes a great winter fuel additive.


Yes, the GP's screw in right in the heads.
They just peak into the cylinder.


Thanks, Yeah, thats the either that does that. I couldn't quite remember.