Priming 6.5 fuel system
 

alright my buddy just picked up a 95 chevy 3500 with a 6.5 yesterday, he got a heck of a deal on the truck, bought it off some old guy for $2500 the truck is in great shape its only got 95k miles on it and had a new tranny with receits at 94k miles, its a extended cab longbox, dually, 4x4, the only thing the truck needs is doors, it has those huge towing mirrors and they rotted holes where they mount the rest of the truck is in great shape and the interior looks like brand new

anyways back to the problem, the return line to the tank was cracked right underneith the cab when he got it, it ran and drove to where it is now, when it got to his barn it started to spudder so he shut it off, it dont have much fuel in it, and now it wont start, so hes going to replace the line that is cracked, and the next step is priming the fuel system, how do we go about doing that, i looked and i cant find any sort of primer or anything, so can anyone point me in the right direction, thanks guys in advance

well it ain't much but i found this.

Open the air bleed valve on top of the fuel manager/filter.
Connect a hose to the air bleed valve located on top of the fuel manager/filter and place the other end of the hose into a suitable container.
Remove F/SOL fuse from fuse panel.
Crank the engine in 10 to 15 second intervals until clear fuel is observed at the air bleed hose (wait for one minute between cranking intervals).
Close the air bleed valve.
Install F/SOL fuse in fuse panel.
Start the engine and allow to run for five minutes at idle.
Check for fuel leaks.

http://alldatapro.com/alldata/PRO~V6...43095/57434874

Take the T-shaped black cover off the firewall on the passenger side and remove the fuel pump fuse, still connected, from its holder. Open the bleeder vent on top of the filter. Take the back side of the fuse, where you would check for current with a test light, and hold it on one of the 12v. studs located on the firewall. That wil send voltage directly to the fuel pump and make it run. Hope this helps.

Ok, this is the quickest way to do it. Remove filter, fill filter housing with diesel, Crack open cylinder 1 injector line at the injector. Crank engine over until you have a steady stream of fuel coming out. Then go to cylinder number 2 and do the same thing. Keep doing this to all the cylinders until you have steady fuel coming from all the injector lines at the injectors.

I have done it this way, all the time and it is the most effective way to bleed a 6.2 or 6.5 gm diesel.

Im going to bump this 3.5 year old thread to ask if this really works? Will fuel prime out of the top of the filter bleeder value buy just holding the back of the fuse to a 12v bolt? And where on the firewall are these located?

Im new so thanks for tips.

Starting a fresh engine/IP and inj change

I have been reading posts from several here that have had issues with getting a fresh engine and or an engine thats seen an IP and injector change started again.

FOR A DS4 system DB2 very similar

The process is simple.

The diesel system is a fuel system designed to run completely air free.
This is not all that different that your brake system (well actually a lot different) in that air compresses and fluid does not.

The Injection pump pushes fuel through the lines to the injectors until it reaches about 2000 PSI and then the injector POPS open and the fuel sprays into the firing chamber.

When starting fresh the system is full of air and this has to be removed before the engine is going to run.

Turning the engine with the starter is about the only option that we have to do this.

Long crank times with the engine fighting compression will kill the starter and the batteries as well as your patience.

Here is the easiest way to get this task done without killing anything.

I will skip some of the obvious steps like "Hook up batteries etc"

Depending on your rigs model year use what ever procedure is needed to get the lift pump running.

Get fuel to the Injector pump inlet (Hose in a cup until fuel flows.

Hook up fuel line to IP

Turn key switch to "ON" only

Run lift pump for approx 45 seconds or so. This will actually purge fuel through the IP and back to the tank.

Now WITH ALL GLOW PLUGS REMOVED (the RH side can be easily accessed via the inner fender access hole with tire off)

NOW
Have a helper watching the glow plug holes (LH side is easy)
Spin the engine over (will spin fast with plugs out)

Usually takes about 30-45 seconds to have fuel mist coming from the plug holes.

Stop and shut off the key switch.

Install the glow plugs and hook up the wires.

Take a deep breath ):h

Turn the key on and allow the glow cycle to complete.

Turn key to start and crank the engine over.
The engine should start in 3-4 seconds providing that all the goodies are working properly. (glow plugs, relays etc)

The engine should start right up and run fairly well using this procedure.

Every set of injectors and every IP is slightly different but thing should go smooth and fairly quick without the usually hastle of bleeding the lines and fooling around with a smokey rough running engine for 30 minutes.

With the engine spinning with glow plugs removed, the IP does not have to fight the compression to force fuel though the lines and out the injectors.

There are small clearances in the injectors that will allow air to escape readily as long as there is no pressure against it.

The engine will spin at around 400 RPM without the plugs in and this greatly speeds up the process.


I hope this helps any who need to restart an engine that has been freshened and or seen the IP and squirts replaced.

Plus while the engine is spinning without compression (Fresh build) you are getting oil pumped up into the system.

Originally Posted by dieselgearhead View Post

Take the T-shaped black cover off the firewall on the passenger side and remove the fuel pump fuse, still connected, from its holder. Open the bleeder vent on top of the filter. Take the back side of the fuse, where you would check for current with a test light, and hold it on one of the 12v. studs located on the firewall. That wil send voltage directly to the fuel pump and make it run. Hope this helps.

Quote:

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Originally Posted by dth0mas (Post 713540)

Im going to bump this 3.5 year old thread to ask if this really works? Will fuel prime out of the top of the filter bleeder value buy just holding the back of the fuse to a 12v bolt? And where on the firewall are these located?

Im new so thanks for tips.

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Thats a great post Crazy but can you answer this question for me?

I am working on a 1985 gmc with a 6.2L and I tried this method but fuel never came through the glow plug holes after several minutes of intermittent cranking. the one thing I was unable to do from these instructions was to get the fuel to the IP before the rest of the steps. Also, is the lifter pump supposed to make noise when the key is on or is it really quiet in this truck?

There is not a electric fuel pump on 85 it is all mechanical. You will have to crank the engine to get the fuel up to the injection pump. It can be a real pain on a older one thats why I do away with the mechanical pump and go to electric.

ok thanks. with the mechanical one will it work by just continuing to crank on it or will I have to do something else to eliminate any potential vapor lock?