SOT (Slightly Off Topic) HELP! I'm stuck in a diesel Suburban that won't go anywhere!
 

Hello,
I know this is a Benz forum, but you've all been so great helping me with my 300D I was hoping someone could give me some insight into a problem I'm having with my Suburban. It's an '83 with a 6.2L V-8 Diesel.

I drove it to a friend's house, took the aircleaner off to see if I could tell where an oil leak was coming from, opened the petcock on the primary fuel filter to drain any water that had accumulated, turned the truck off, did some other things inside, came back out about 30 minutes later, started her up, backed out of the driveway, and she died and won't start again. Turns over until I kill the battery, but won't start. I pulled off the primary fuel filter and tried to start it. nothing is coming out of the input into the filter. Could my fuel pump have randomly died? I filled the filter back up with tranny fluid and tried starting it. Nothing. pulled the filter again and it was still full of fluid- nothing had been pulled into the motor while I was attempting to crank it. I'm stuck over here an hour from home until I can figure it out. If you have any ideas or questions, please let me know asap!!! Heck, if you want, PM me your number and I'll call you if you think you have an insight. Whatever, I just need to get home!!!
-Michael

Check out these pages:

http://dieselplace.com/forum/archive/index.php?t-17436.html
http://www.dieseldoctor.com/messageboard/data/56.html
http://experts.about.com/q/GM-GMC-781/1984-6-2L-Diesel.htm
http://www.gm-diesel.com/diesel/vbull/showthread.php?t=16091

From what I gather, you need a new lift pump.

phoenix,

Open the bleed screw on the top of the fuel filter and crank the engine. When fuel squirts out close the bleed screw and the engine should start with a little more cranking.

If no fuel comes out, U are out of fuel, lift pump is bad, lines are blocked or the dual tank switchover valve is bad.

P E H

Post on the diesel place, as the guys there will definately look after you, chances are some one on the board lives near you and can help out, I haunt the 6.5 section over there (alot) now if you were running a 6.5 I'd have lots of suggestions, the 6.2 runs a mechanical pump not sure if they have a lift pump or not. anyway there is a great resourse there...take advantage of it
Nick

You have a mechanical lift pump on the pass side lower portion of the motor. Its job is to fill the main fuel filter by pushing the fuel up to the firewall and in. When you open the petcock on the top of the primary filter housing air should come out and then fuel while you are cranking. That being said, many 6.2's run fine with that pump totaly non-functional. Most people only notice they are shot when they doa filter change and it wont restart. However since you refilled the filter by hand, your problem is most likely air in the lines further downstream. The best way to fix it is to crack the injector lines at the injectors and crank till you see fuel at the fitting then tighten. Do that for all of them. If its anything like the 6.2 in my 81 blazer, it will prolly fire off and run before you complete the procedure on all 8 lines. I can tell you this same thing happened to me twice. The first time was the air lock that i just described how to fix. I went through looking into the kift pump and pimcked lines and clogged secondary filters. Was a simple airlock the whole time. The second time it was something far more insideous thats very common on the DB2 injection pump until the 84-85 model year when they changed from a plastic govenor ring to a steel one.

Fuel Return
 

After checking the other suggestions first, on the front top of the injection pump, there is a fuel return fitting that has a check valve/ball in it. It looks like a normal open fitting to attach a rubber fuel line but inside there is a check valve. Try removing the line from this fitting, then remove the fitting from the injection pump and using carb cleaner and a stiff paper clip, work the check valve clean. After cleaning in this manner, see if it will run. It may re-clog quickly however....

I don't have much experience with these 6.2 motors but my son's truck has one and it stumped us for a while until I discovered this.....

If there is gunk in that valve, its the first sign of the impending decline of the govenor housing. As the plastic shreds and dissolves the chunks end up in that valve and plug it up. Keep your fingers crossed that its an air lock :)

too complicated.

you just lost prime. imho

get some wd 40 and spray into the intake with the filter out with a friend cranking the engine. keep spraying til it will run without the spray. it will run fine on the spray. no ether though.

put air filter back on and drink a beer.

tom w

Not sure if you have tried this recently but the formula for WD40 has changed in the last few years. This trick no longer works for me and I have read the same on other forums. You can try it but you are only going to end up with a mess on your manifold. Unless you have an old can of the stuff.

Sounds like you got air in the fuel line. You should crack each injector line and crank. If you remove the GP's it'll crank alot easier. Well atleast that's how I got my F250 to start when there was air in the system.

Good luck

Marty

There is only 1 way I can always get WD40 to light off. Spray it onto a VERY hot surface (Like metal after a torch has it cherry red) and use a lighter to ignite the vapor.

Most likely you just need to purge air. However, I have an '83 6.2 also, and it one time exhibited the same symptoms from a suddenly dead shutoff solenoid. You have a solenoid in the bowl of your IP which has an electrical wire to it. If it dies you simply won't ever start. Easy to check. I think it's the red wire on the front of your pump. Unplug it, and then put the ignition key in the 'on' position. Touch the wire to the spade terminal, and if it's working, you will definitely hear a clicking noise within. If not, it's dead.

Just a possibility, although I'm inclined to go with the air theory.

Ben

i have not tried it lately.

diesel in a hand pumped spray should work too.

tom w

Had my 6.2 vapor or air locked once. Bled it off at the filter and off she went.

Fuel gauge work ok? Might be out of fuel too.

Cheers,

Bill