Bad glow plugs replaced, now it starts but won't run?

So we just got done with all sorts of work to my 98 6.5. New injectors, cooling system, exhaust, and glow plugs, relay, and harness.

After we put it all back together, it started right up and ran great. After a few more starts, and about an hour of total run time, it wouldn't start even though it tried. It would start with just the tiniest amount of ether, though and continued to run fine. I only did that 3 times.

To try to fix it, we changed the fuel shutoff solenoid, tried unplugging the coolant temperature sensor, and changed the fuel filter. We bled the system by using the T-valve, and letting the air escape from the filter housing. It still wouldn't start.

Come to find out, 6 of the 7 (oone was broke) glow plugs stopped working and swelled. Stupid Autolites. That was my first mistake. Anyway, we got all those out and replaced them with ACDelco. Now, the truck will start right up but it won't run longer than a few revolutions at most. I have blue/white smoke coming out the exhaust, so I know it's at least getting SOME fuel. I can also open the fuel filter, turn the key, and diesel pours out steady.

I've tried a new PMD with no luck. Mh only thought is that there is still air trapped someehere. I know one suggestion is to crank with an injector line cracked, but with the amount of cranking we've done, I'd think the air would be gone now.

I'm going to try taking the fuel cap off the tank tomorrow just in case it's a vacuum lock issue. Does anyone have any other ideas or suggestions? It's kind of frustrating that my problems are now reversed!

Thanks for the reply, however, I think you missed the main point. The truck ran fine, but didn't start due to the glow plugs going out. I didn't use any ether on it until they wen th bad. When they went bad, they had only been used a handful of times, and like I said, the engine only had about an hour of total run time with them installed.

Once I replaced them again, and thd lift pump and shutoff solenoid, it would start but not run.

The Autolites that failed were 1112s. The glow system is now operating properly, as I have voltage at all 8 connectors. I bench tested all of the new ACDelco plugs this last time before installing them. Like I said, it starts but doesn't run.

I'd hate to think it's the injection pump, because it ran fine before this, but I'm kind of running out of ideas, and things to replace! If it's not that, then there's some really stubborn air stuck in the system somehow.

I wonder if the optical sensor could do this? Is there another fuel solenoid somewhere?

I will see if there are any DTCs today. I know there weren't when j pulled it in the shop, but maybe something was triggered between then and now.

Worse comes to worst, I'll tow it to a diesel shop and see what they come up with. Got to get it running for camping season. I have a new 37ft fifth wheel that's itching to get used this year since the only trip it's had with me is about an hour on the way home from the dealer.

What did you use for injectors? It's pretty hard to mess up a 6.5 injector, but as process of elimination...

If you want a set of plugs that works and will not swell the QH plugs on our site cannot be beat. AC Delco plugs tend to be quite slow.

Auotlite 1112 specs- 10.5V @ 68?W.
Replaces ACDelco 60g.

ACDelco 60gs specs- 10.5vt @ 200W.
Replaces ACDelco 9g.


ACDelco 9gs are 6vt @ 200WT.

Notice the voltage requirements?
The 6vt GPs were intended to operate @ 12vt in order to significantly shorten and greatly improve cold weather/engine start ups...

Glow plugs just dont go out, they are often helped along by either hastily double/triple cycle the GP system, or the GP system is malfunctioning and the GPs are remaining ON (faulty relay), but you replaced the relay too..
Id make sure it was connected properly, specially the two large post. One is the main batt power to the GPR and the other powers all the glow plugs when commanded to (via yellow wire IIRC).

Nearly all cases of swollen glow plugs were the result of misuse, and/or improper operation..
1. manual override to extend glow time when a couple GP started to fail.
2. replaced defectives with mismatched replacements (5x 9gs + 3x 60gs= no improvements) that failed to improve cold starts, see #1.

If your using anything other than a 6vt replacement GP, you will likely need to extend glow times accordingly via over-ride the PCM's precise control...

Quote:

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Originally Posted by campionc

Thanks for the reply, however, I think you missed the main point. The truck ran fine, but didn't start due to the glow plugs going out. I didn't use any ether on it until they wen th bad. When they went bad, they had only been used a handful of times, and like I said, the engine only had about an hour of total run time with them installed.

Once I replaced them again, and thd lift pump and shutoff solenoid, it would start but not run.

The Autolites that failed were 1112s. The glow system is now operating properly, as I have voltage at all 8 connectors. I bench tested all of the new ACDelco plugs this last time before installing them. Like I said, it starts but doesn't run.

I'd hate to think it's the injection pump, because it ran fine before this, but I'm kind of running out of ideas, and things to replace! If it's not that, then there's some really stubborn air stuck in the system somehow.

I wonder if the optical sensor could do this? Is there another fuel solenoid somewhere?

I will see if there are any DTCs today. I know there weren't when j pulled it in the shop, but maybe something was triggered between then and now.

Worse comes to worst, I'll tow it to a diesel shop and see what they come up with. Got to get it running for camping season. I have a new 37ft fifth wheel that's itching to get used this year since the only trip it's had with me is about an hour on the way home from the dealer.

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Well, all I can tell you is that the power to the glow plug connectors power on and off the way they should, and the replacement harness was installed one step at a time to make sure wires didn't get crossed.

The replacement plugs are 60g, but I don't see that as a real issue right now. The original glow plugs that came with the truck worked, but I could tell they were getting weak. I have no idea what kind they were. I have no explanation for the swelling of the Autolites. They weren't and couldn't be abused as they were only used 5 or 6 times. There was no improper use as the truck fired up and ran the first time we tried starting it after the first round of work was complete, before the starting issue.

The plugs are not the issue now. I know they work. The truck startd. It just dies right afterwards.

The new injectors are Standard FJ173 from RockAuto. I can't imagine them being bad either, as it ran before swapping plugs. I know there are better rated injectors, but most posts about these have been good.

I checked the fuel lines again today with no apparent problems. I still have to check for codes. I'll post them if there are any.

Maybe an issue with PMD extension harness? Crank position sensor? I know the PMD harness could be intermittent, how about the CPS?

Howdy
If the truck starts and dies RIGHT AWAY...and does this ALL the time...it could be the theft deterrent system needs to be reset. Happened to me in the middle of Oklahoma. Sounds like exactly what my truck was doing.
I had inadvertently activated the theft system by reaching in the window and opening the door...:rolleyes: Whatever...It took me by surprise and I ended up bringing it to a dealer(tow truck for the yankee:mad:) and they hooked up tech2000 and fixed the problem for free:)

Indicator was that the "theft" light on the dash would come on with the key in the run position and not go out.

The truck would fire, run for maybe 1-2 seconds and shut down just like you turned off the key.

There is a procedure of key manipulations that will clear this out but I do not remember what it is.

If your symptoms are similar then it might be worth a shot.

Good luck!

...another thing....
In my experience in USMC the 9g GPs were worthless.

They swelled and were almost impossible to get out.

They had a very limited life span and were very sensitive to voltage time cycles. Too much time would smoke them. We used to blow them in the arctic just by cycling the system consecutively so that the truck would start.

They worked only marginally OK when they were good.

The only thing worse than 9gs were autolights. Only worse than autolights are some the ebay GPs that are made in china.

I have always had great results with either the 60g or the Quickheats. NEVER burned out any of those.

I will start a fire under my truck before I use ether!!! If you do have to use it fallow the specific instructions on this web sight for use in 6.5/6.2. Using ether improperly will result in BAD things:(:(

Problem solved. The new fuel shutoff solenoid I had installed while troubleshooting this mess was defective. Replaced with the old one and it fired right up and ran with no problems.

Thanks to all who tried to help!

Quote:

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Originally Posted by campionc

Problem solved. The new fuel shutoff solenoid I had installed while troubleshooting this mess was defective. Replaced with the old one and it fired right up and ran with no problems.

Thanks to all who tried to help!

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New Stanadyne, or aftermarket?

About the only mode of failure for these is for the early ones to leak. Otherwise they seem to just keep going...

I got a new ACDelco unit.

It wasn't a leak, actually there was some sort of piece of metal that wouldn't let the plunger retract.

The one that failed came from Diesel Care and Performance from Tennessee. And boy was it fun trying to get them to take the thing back. After my email to them stating what the problem was and that I couldn't wait for them to send a replacement, they tried to charge me a 15% restocking fee. I complained enough (for about a page length) that there was NO mention ANYWHERE about a restocking fee, and I wasn't going to pay a restocking fee for returning a defective product, and how are they going to restock an item that's been installed, is covered in diesel fuel, and can't be resold because it's defective? I even mentioned that I was made aware of the games they play with their customers (thanks to forums like this), and that I know very well how to handle problems like this.

By the time I was done, I received two personal apologies, the removal of the fee, AND a prepaid return label. The person who handled this said that she "misread" mh original email and thought it was saying something else.

When I packed it up for UPS, I realized that there wasn't a brand name anywhere on it. The box looked plain, and it only had one label on it, that said, "Fuel Solenoid". LOL

In most cases I recommend GM/AC Delco stuff hands down over the rest, but in this case I can only guess that GM's relationship with Stanadyne has ended and that they are sourcing aftermarket (Dtech?) parts hence the failure of a new part and the generic packaging.

The Stanadyne stuff is not perfect and I never thought I'd be standing up for them, but they are getting better and at least their stuff works out of the box and does provide a decent service life.

I have at least one dealer friend (GM) who sources his 6.5 fuel system parts through us rather than use the aftermarket stuff that GM now sells.