6.2 starting issues

[brown82]

Ok I figured out the cranking issue(the safety neutral switch was just laying up under dash and I didn't realize what it was and toyed with it).

I have(in my mind) purged the diesel fuel system. I disconnected the fuel lines to each cylinder and crank until diesel was coming out. I then reconnected and tighten the lines up. Now I have think I burnt up the starter cause it makes a really bad noise. But not until I must of spent 5 minutes trying to get the damn thing started. It didn't once act like it was getting fuel.

I don't know much about diesels. Did I screw up something? I have 10+ gallons in the LS tank.


James

[86c20]

are the glow plugs working at all? these 6.2's neeed them for first start. they will turn over all day and not start. diesel heat and compression you need both. you may have burt the starter if you did a continus crank like that. 30 seconds crank at last 15 seconds off and the longer you do this the longder you need to let it cool still at the 30 second crank. the other thing is to use a rag with little gas on it over the intake hose or a shot of wd40 and that is with OUT the glow plugs also make sure you have all the wires on the pump hooked up as i think it is the green wire one the left (looking for the front) that it needs to start. see what you ge t and get back to us. latter, mike

[brown82]

Originally Posted by 86c20

are the glow plugs working at all?. latter, mike

I have researched(a little) about glow plugs. From what I have read "a" way to know they are working properly is to wait for the wait light and glow light to go off and then begin cranking. Repeat until it starts. Is that correct?

the other thing is to use a rag with little gas on it over the intake hose or a shot of wd40 and that is with OUT the glow plugs

Is this to help purge the air out of the lines? I'm not sure why you mentioned this. Please elaborate more for me if you don't mind.


My batteries are draining very quickly like on the very first 15 seconds of cranking. It has been in the 40/50's at night. But I just had both batteries recharged and they are under 6 months old. The truck is plugged in if that information is asked.

I plan to attack it again tonight. But would like to know first why I should use a rag. I just want to know what the outcome of it is suppose to be.


Thanks again guys.

James

[rcbildr]

Is white smoke coming out of the exhaust when you are cranking it? Check the pink wire on your injector pump for voltage. Go buy a haynes manual for diesel engines...it will say it covers the 6.2L and a couple others. That book helped me out a lot when I first got my Burb.

[Edahall]

If you have to replace the starter, an upgrade would be to get a gear starter for a 6.5L diesel. It's a direct bolt in.

[hatzie]

Pull all 8 glow plugs unplug the glow plug relay and crank it to prime it. Much easier on the starter.

[brown82]

Originally Posted by hatzie

Pull all 8 glow plugs unplug the glow plug relay and crank it to prime it. Much easier on the starter.

This is on top of disconnecting the fuel lines correct? Sorry that I'm being difficult.

James

[gmclowsierra]

Unplug all the glow plugs. Take a test light and clip it to the positive terminal of the battery. Touch the probe end of the test light to the terminal of the glow plug. If the test light lights the glow plug is ok. If they dont light you need to replace those glow plugs. If they all light then you need to test the relay. Put your test light lead on negative terminal touch the probe end to the wire of one glow plug. Cycle the key so the dash light lites. The test light should light as long as the glow plug dash light is on
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[86c20]

the rag with gas is to start the truck not perg the lines. but if you can get it to stumble it should start. do as gmc says and test them all and the relay. if you have good glow plugs and you have fuel then you need compression. what do you know about this motor? also if it is pluged in make shure the heater is working. i think they worm to about 60 degress?? some one correct me on that plz. some of the plug systems are 6 volt not 12 or so i have been told. yet to see one. check your pump wires make sure they are all hooked up, the wire on the left needs to be hooked up or it wont start. ask me how i know that one lol.

[brown82]

Ok, what is a pump wire? What is the "left" wire you are referring to that needs hooked up or it wont start located?


James

[hatzie]

Originally Posted by brown82

Ok, what is a pump wire? What is the "left" wire you are referring to that needs hooked up or it wont start located?


James

Wires on the 6.2 DB2 Injection pump. Both are hooked to the housing cover...

There is a single pink wire to the FSS (Fuel Shutoff Solenoid). It should have 12volts with the ignition on. You should hear the cutoff clicking when you unplug the pink wire.

You should also see a green wire hooked up to the fast idle solenoid and the HPCA (Housing Pressure Cold Advance).

See picture below. I believe the FSS is the connection on top of the housing and the HPCA is on the side. It's been a while since I messed with this so I reserve the right to be wrong. Please pipe up and correct me if I am mistaken...

[Corts60]

Ok, I have to step in here a second. First of all, with your amount of experience with diesels, DO NOT use WD40, DO NOT use a gas soaked rag, and DO NOT put gasoline in the intake or ATF in the fuel filter. I am an experienced diesel mechanic and I have never had to resort to any of those tactics to get a diesel started. They are dangerous situations even if you know what you are doing, so please for the love of your engine do not try these suggestions.

First, do as hatzie mentioned above and if you have power to the injection pump, do these steps next:
You need to figure out if your glow plugs are indeed working. The easiest way will be for you to completely pull out all of your glow plugs. Once they are removed, take one at a time and hook a jumper wire from a positive battery source and connect it to the male spade terminal on the glow plug. Next, take a negative jumper and lightly touch it to the threads on the glow plug. It will only take about half a second for the glow plug tip to heat to the point you can't touch it so be very careful. If you feel heat, the flow plug is working. Do this procedure with all and then reinstall if they are good. Get new ones if they are not.

Complete this step first then get back to us before you try anything else. We'll move on from there.
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[hatzie]

Did you completely disconnect the fuel lines from the injectors? If so then this may be part of the problem. The prime can drain out of the lines while you're re-installing them

You need to crack the fuel lines enough to break the seal but not disconnect them. When fuel exits the fitting re-tighten it. Hook up a remote start button or have an assistant crank the engine. ALWAYS wear a full face mask and DO NOT put your skin in the spraying fuel.

I've primed my older 1.6 IDI VW diesels and my 6.5 GM by filling the fuel filter with ATF, putting 4-6 drips of gasoline in the intake with an eyedropper (don't slosh it in), and cranking with the air filter back in place. The hydraulic fluid base of the ATF provides pump lubrication and the gasoline vapor will fire the engine for a few revs (without blowing chunks out of the ring lands or crowns of the pistons like Ether). I've usually gotten em to lope along for long enough to blow the air through on one session of gasoline drips... Yes the ATF makes it smoke like a freight train for a few seconds.

[gmclowsierra]

Wf use atf everyday to fill fuel filters when we change them never had a problem. Like i said check the gloe plugs the way i described is easier anf you wont burn yourself.
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[Corts60]

Originally Posted by gmclowsierra

Wf use atf everyday to fill fuel filters when we change them never had a problem. Like i said check the gloe plugs the way i described is easier anf you wont burn yourself.
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I don't even understand why you do this. Is there no diesel available to prime the new filters with? Besides, we need to keep things simple as the OP already stated he doesn't know much about diesels.

[hatzie]

Originally Posted by gmclowsierra

Wf use atf everyday to fill fuel filters when we change them never had a problem. Like i said check the gloe plugs the way i described is easier anf you wont burn yourself.
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I've always used fresh unopened ATF to prime the spin on canister fuel filters on my diesel cars, trucks, tractors, and loaders. All three of my trucks have all been upgraded with or already had 1995+ OEM GM electric fuel pumps and the 1995+ OEM GM Stanadyne heated top loading fuel filter assembly. I used ATF in the Racor and CAT filters prior to the recent upgrades. ATF is positively clean, it won't hurt the fuel system, and there's much less air to blow through. More than 3/4 of it goes back through the return line to mix and dilute in the full tank.

X2 on metering the glow plugs. Feeding them 12volts can burn them out. GM and Ford used 6v glow plugs with a cycling relay to allow faster heat up times without burning them out.

Using a good digital meter... Not all of us believe in test lights.
Set the meter to 20 VDC range or VDC on an auto-ranging meter.
Firmly attach the + lead to either battery positive then check battery voltage by touching the - lead to that batteries' ground. Testing the Left bank off the left battery and right bank off the right battery will allow the leads to reach with a good view of the display.
Check each glow plug by unplugging it and touching glow plug tang with the - lead.
If a plug doesn't read extremely close to the battery voltage you got with the - lead on the battery ground... it's bad.

It's worth noting that if I find more than 2 bad glow plugs I replace all 8 with new AC-60Gs. Why? When a glow plug burns out the system has more amps available to overstress the remaining good ones. If two or three have reached their cycle life the rest aren't far behind.

It's also worth noting that I always put a tiny amount of Never-Seeze in the threads of my glow plugs and injectors. I use a cheap kids watercolor brush to apply a small amount to just the threads. Don't slop it on with the provided brush. DO NOT get any below the threads of the glow plugs or injectors, ABSOLUTELY DO NOT get it on the glow plug tips, and DO NOT get any on the fuel fittings of the injectors.

[legendman]

Who knows what is in a bottle of ATF these days, I wouldn't chance doing damage to a injection pump when some diesel is readily available.

[brown82]

all glow plugs are ok.

THat pink wire has 11.8v and that green wire causes a noise when pulled off(can't describe it but I'm sure its what you mean its suppose to do).

Side note: the wife is getting angry this truck is sitting out in front of her house.


James

[hatzie]

When you unplug the pink wire the Fuel Shutoff Solenoid should make a noise. It's silent?
That usually means the Fuel Solenoid is dead. That would definitely give a no-start.

Is the pink wire plugged into the Fuel Solenoid marked in the picture below?

[brown82]

Oops, THAT'S my fault. I miss read which wire to unhook. I unhooked the green one with the ignition in the on position.
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[hatzie]

Ignition on. Pull the pink FSS wire. It should click like the green HPCA wire. HPCA only clicks when the engine is cold.

[brown82]

It clicks.

NEXT

[hatzie]

HPCA & FSS are working. The actual Glow Plugs test OK.

The early glow plug control systems are not noted for high reliability.

Does the Wait light turn on for at least 6 seconds after you first switch on the ignition?

Can you hear the glow plug relay clicking with the ignition? If the controller is working then the relay will click but only stay switched for 6 seconds.

Are both LH & RH banks of glow plugs getting 12vdc just after the ignition is switched on and the "wait" light is lit?

If the relay isn't switching the controller is probably toast. You can switch the glow plug relay by grounding the terminal that's attached to the blue wire. Don't run the plugs this way for more than 6 seconds.

[brown82]

yes to all questions [B]BUT[B] for knowing if both banks are getting 12v's on each bank. Will check for that tomorrow.

[brown82]

12v on both banks.

NEXT
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