6.2 Diesel Hard Start Checklist

[Sterling]

6.2 diesel Hard Start Guide


These old Detroit's can be great engines if properly maintained.

We here in the midwest are getting really cold, so I thought I'd share a little handy checklist to make sure you keep your oil burner going through the cold

Please use this thread to post your suggestions and helpful hints on getting these old diesels starting perfect at any temp.

Engines need only 3 things to run (taught in basic autos class )

Fuel
Spark (for us, its compression and glow plugs)
And compression

So for Diesels, its more like

Fuel
Compression
Compression

1 - Glow plugs / Engine pre heating

Indirect Injection Diesels need the glow plugs to pre heat the combustion chamber, for they do not get as hot as direct injections due to the distance from the piston to the injector among other factors.

Old swollen glow plugs, faulty glow plug controllers, and faulty glow plug relays all can lead to catastrophic failure, and your inability to start.

Fixes:

AC Delco 60 G glow plugs. These plugs do not swell, and if you dont know what that means, the tip becomes bigger then the threads, so you will have a bad time getting swollen GP's out. They are self limiting, you can run them many times in a row and they wont get too hot and swell. Allows you to get the pre combustion chamber to the right temp every time

Manual Glow plug controller (i.e. $2 on off switch and a few wires)

Many write ups on this. Allows you to control how much you want the glow plugs to run. I usually just run them until my seat belt buzzer shuts off. Starts right up every time. I know for my 82 block, a new controller was $100. psh plleeaasse, like I'd dump that on part.

Glow plug relay (Do I dare say it...and $9)

This is the one FORD part you should have in your truck (please don't ban me for dropping the F-Word, im new)
But really, the F-RD starter relay you see on the inner fender of most of the cars in the junk yard (ha-ha) is actually a great glow plug relay.

DO NOT USE ETHER AT ANY POINT

http://www.orangetractortalks.com/wo...ownengine2.jpg

Is a $2 bottle of engine death really worth new cylinder heads, pistons, and rods? Ether is like a hard drug, your engine WILL become addicted, and will not wanna get off it quick.

Ether users will be sent straight to Jiffy lube (automotive jail, get it? ) for the rest of their maintenance. But hey, its your engine, but I get to say "I told you so" when you have to start buying stock in starter fluid because your practically buying out their wholes stock to keep your truck starting.


2- Fuel

You need Fuel going to injector pump, and you need fuel going into cylinders

Fuel to pump

Lift pump - $20

Check to make sure your LIFT pump works, and is the updated model

Gm released a service bulletin that updated the lift pumps design. A poor check valve (anti drain back valve for us dummies) let diesel fuel seep back into the gas tank, causing hard starting due to the fact you must crank fuel all the way from tank to engine.

If it is beyond the lift pump, check to make sure you don't have air in the system. Bleed the diesel lines, and make sure no rubber hoses are cracked and letting air in.


3 - Compression

Is your engine a high mileage, white smoke blowing 6.2? Have you tried everything else and are slamming your head against your front fender?

Try doing a compression test of the cylinders. Get a gauge that fits into the glow plugs holes and goes past 400 psi. Remove all glow plugs, and test each cylinder 1 by 1. You should get high 300's to low 400's, but really want to be looking for symmetry in all the cylinders.

TO CHECK LOW COMPRESSION CYLINDERS FOR BLOWBY/PISTON RING FAILURE

Take some motor oil, and pour a tiny bit into the cylinder your checking. Id say a few OZ is good. Put compression gauge in and crank it over. If you have much better compression, your rings are bad. If not, problems in cylinder head, or you have a REALLY messed up cylinder or cracked piston

That is about it for picking my brain, what do you all have

I've found these engines to be relatively simple once you dig into them. At first I thought, what did I get myself into. But with a clean head and open mind, I dug in to find out just how these things really work. And to be honest, I got frustrated at points. But I stuck with it, and hey, if a 1_ year old guy can do it, I am sure you can too!!! Just keep your head clear, take a break if you get frustrated, and your truck WILL run! It just may take a lot more stop leak and duct tape then you expected

-Sterling

[Corts60]

Well done man! Thanks for posting.
Posted via Mobile Device

[68Timber]

I've had mine a few years. It only gets down into the 20's at worst where I live, lows in the 30's is more common here. But the truck always busts right off in the cold with one cycle of the glow plugs.

Thanks for putting that together, I know gas much better than diesel.

[hatzie]

Do you have a copy of the lift pump TSB or the doc #?

[Sterling]

Bulletin found HERE

#89-329-6