Help starting a DD 8V71 after a couple years of storage

rdiercks · March 27, 2016, 09:13:40 AM

Looking for some help with starting a Detroit 8V71 in a MCI M-7 bus.
It has sat for a couple years. Got it to sputter a few times yesterday.
Then I think the fuel lines were dry.
What's the best way to primed those fuel lines before I try a startup again?
I think I've read somewhere that temporarily loosening some fuel lines, spinning the motor briefly, then re-tightening and restarting it might be the best way. Any truth to this idea?
If so, which fuel fittings should be loosened?
Thanks for any help with this.

luvrbus · March 27, 2016, 09:24:15 AM

Just remove the plug on top of the filter base pump a gal or so fuel through the filters with some type pump electric or manual makes no difference what type then it will fire,the fuel pumped will just return to the tank it is not a complicated process

eagle19952 · March 27, 2016, 11:03:27 AM

Quote from: luvrbus on March 27, 2016, 09:24:15 AM
Just remove the plug on top of the filter base pump a gal or so fuel through the filters with some type pump electric or manual make no difference what type then it will fire,the fuel pumped will just return to the tank it is not a complicated process

The two filters nearest the front are fuel, the fuel lines arrangements are versatile. That said the allen plug on the side or if one is vacant on the top... those would be the "priming points" of choice.

chessie4905 · March 27, 2016, 03:01:06 PM

Hey Don, if you plan to throw away that engine, I could make use or it.

Greg Smith · March 27, 2016, 03:06:25 PM

When I bought my 76 MCI-8, it had been sitting for about 4 years. I cut the fuel line at the tank, installed a 12v Carter fuel pump, hooked to one battery, wired to a toggle switch. When not in use, the fuel flows freely through the pump. I use it every spring or when it's cold. Works fantastic, even if you run out of fuel, priming is a snap.

DoubleEagle · March 27, 2016, 08:01:39 PM

The previous suggestions are good. In the future either have an electric pump in line to be able to feed it, or eliminate the two spin-on filters and go to the single fuel processor that has a plastic dome with a cap on top where you can add fuel if you run out. In operation you can see the filter element and the fuel level. It starts low and rises as the filter gets used. I got one from Williams Diesel in Las Vegas after seeing it at one of the MAK bus conventions back in the nineties. I ran out of fuel once on the side of a hill. I poured fuel in the top, and got over it and to the exit. Much better than adding fuel to the spin-ons.

Oonrahnjay · March 28, 2016, 04:08:32 AM

Quote from: DoubleEagle on March 27, 2016, 08:01:39 PM
The previous suggestions are good. In the future either have an electric pump in line to be able to feed it, or eliminate the two spin-on filters and go to the single fuel processor that has a plastic dome with a cap on top where you can add fuel if you run out. In operation you can see the filter element and the fuel level. It starts low and rises as the filter gets used. I got one from Williams Diesel in Las Vegas after seeing it at one of the MAK bus conventions back in the nineties. I ran out of fuel once on the side of a hill. I poured fuel in the top, and got over it and to the exit. Much better than adding fuel to the spin-ons.

That's great information and useful experience to remember. Thanks for that! BH

luvrbus · March 28, 2016, 06:41:13 AM

That's a Davco fuel processor he is talking about Bruce they are getting cheap now because of so many out there.They can be the pits when they start going bad though

TomC · March 28, 2016, 07:31:45 AM

Davco filters (which is owned by Detroit Diesel) are so good, Freightliner drills their frame in the engine compartment standard whether you order one or not. Davco makes a special model (482) just for the DD engines. The 483 are for other engines. The big advantage to the Davco is there is no question about when it needs to be changed since it has a clear bowl. Davco looks like an upside down filter with the clear filter bowl at the top. As the filter gets dirty, the fuel moves up the bowl to find clean filter. When the fuel level gets to the line on the bowl that says change filter, then it is time to change the filter, no question, no premature changing. Davco filters are also available with both 120v, 12v, (I think) 24v heat. But as Clifford said, yes they are a bitch if they leak-but that's usually easy to see also since you can see bubbles in the clear bowl. Good Luck, TomC

eagle19952 · March 28, 2016, 08:55:45 AM

Detroit has used the two filter system for a long time. It is more than adequate. It isn't that hard to assure the integrity of the fuel system, and spending big bucks (or any bucks) for a band aid makes absolutely no sense to me... YMMV.

About like putting training wheels on your motorcycle.

I suppose a 1 gallon garden sprayer beats the heck out of a siphon hose and a 5 gallon container

DoubleEagle · March 28, 2016, 09:13:02 AM

Quote from: eagle19952 on March 28, 2016, 08:55:45 AM
Detroit has used the two filter system for a long time. It is more than adequate. It isn't that hard to assure the integrity of the fuel system, and spending big bucks (or any bucks) for a band aid makes absolutely no sense to me... YMMV.

About like putting training wheels on your motorcycle.
I suppose a 1 gallon garden sprayer beats the heck out of a siphon hose and a 5 gallon container

Yes, that is true, the spin-on's worked, and they were an improvement over replacing filter elements in a canister, but the fuel processors are the next step. If you get a bad load of contaminated fuel, the spin-on's will not notify you which one is clogged or allow you to change the filter without any priming problems, or have a water drain, or heated fuel in the winter. I have had one on my 8V71 since 1996 with no problems. I was fearful and hesitant at first, and I kept my old spin-on mounts just in case, but I have not gone back. It is sort of like those LED HD TV's, do you really want to go back to tube-type TV's?

luvrbus · March 28, 2016, 09:36:12 AM

Quote from: DoubleEagle on March 28, 2016, 09:13:02 AM
Yes, that is true, the spin-on's worked, and they were an improvement over replacing filter elements in a canister, but the fuel processors are the next step. If you get a bad load of contaminated fuel, the spin-on's will not notify you which one is clogged or allow you to change the filter without any priming problems, or have a water drain, or heated fuel in the winter. I have had one on my 8V71 since 1996 with no problems. I was fearful and hesitant at first, and I kept my old spin-on mounts just in case, but I have not gone back. It is sort of like those LED HD TV's, do you really want to go back to tube-type TV's?

Lol have you guys ever changed the oil filters on a DD 13 the latest and greatest improvement for DD they went back to canister type oil filters

Oonrahnjay · March 28, 2016, 10:52:16 AM

Quote from: luvrbus on March 28, 2016, 06:41:13 AMThat's a Davco fuel processor he is talking about Bruce they are getting cheap now because of so many out there.They can be the pits when they start going bad though

Yes, I have one that came off the "donor bus" for my 8.3 Cummins ISC engine. I don't have DD-type dual fiilters (the ones originally on my bus were bassetbaw socks stretched over the wire frame - honest!)