HELP - priming 7.3 IDI

[newbury]

I changed the fuel filter in my '88 7.3L IDI E350 VAN. Getting the old filter off took a while due to limited room and big hands, and getting the water drain off required me taking it inside to put in a vise. The replacement filter was also a pain to put on the end result was that I "lost" prime on the fuel line big time. I know the fuel pump is working because when I was putting the filter back on the first time I didn't get it tight enough and it squirted diesel all over.

I'm trying to reprime it with 20 seconds of cranking with several minutes of cool down as I've read so I don't burn out my starter. I've "cracked" an injector line.

I've read discussions saying it will take lot's of cranks and read one post saying it might take recharging the batteries a couple of times.

I also just replaced the batteries.

Questions - Should I crack more injector lines?
Realistically how many times should I expect to due 20 seconds of cranking before suspecting injector pump failure?
Does pressing the Schrader valve on the filter housing help?
Any other suggestions ?

Thanks

 

[tcartwri]

I usually go right for the return line and loosen it quite a bit to make sure fuel is moving through the pump. When you get a steady flow at that point, retighten, and then crack all the injector fittings about half a turn. When it starts, you just start snugging them down until the leakage stops.

disclaimer, have never personally worked on an idi.

Found this write up that I thought was pretty good.

http://oilburners.net/brian/idi/FuelInjectionServicing.htm

 

[dex3361]

I changed the fuel filter in my '88 7.3L IDI E350 VAN. Getting the old filter off took a while due to limited room and big hands, and getting the water drain off required me taking it inside to put in a vise. The replacement filter was also a pain to put on the end result was that I "lost" prime on the fuel line big time. I know the fuel pump is working because when I was putting the filter back on the first time I didn't get it tight enough and it squirted diesel all over.

I'm trying to reprime it with 20 seconds of cranking with several minutes of cool down as I've read so I don't burn out my starter. I've "cracked" an injector line.

I've read discussions saying it will take lot's of cranks and read one post saying it might take recharging the batteries a couple of times.

I also just replaced the batteries.

Questions - Should I crack more injector lines?
Realistically how many times should I expect to due 20 seconds of cranking before suspecting injector pump failure?
Does pressing the Schrader valve on the filter housing help?
Any other suggestions ?

Thanks

I have a 93 IDI 7.3 in a ford F250 and I feel your pain.

THE LONG WAY:
I usually fill the filter most of the way up with diesel before spinning it on.

Then I press the Schrader valve in while someone cranks it over (always keep in mind the overheating of the starter 20 seconds cranking and 5 minutes off).

Then I usually crack the injector lines and crank it over, when I see fuel (sometimes it starts at this point) I tighten the injectors a little it should start at this point if it hasn't already.

Tighten all the injectors.

 

[dex3361]

The short way works with standard trans trucks fill the spin on filter and bleed the air out with the Schrader valve.

Hook up a pull vehicle and pull start the truck, this is easier on the starter and you do have to pulls a ways sometimes.

 

[newbury]

Thanks guys
I had filled the filter prior to putting it on.
Pushing in the Schrader valve got me a fist full of fuel.
I've gone thru about 20 cycles of 20 to 30 seconds of crank w/ 2 to 10 minutes off.
I've cracked 4 of the 8 injectors (not much room in the van).

How many more should I expect to need to do?

 

[tcartwri]

Any fuel at all getting past the injector fittings?

 

[newbury]

Not yet, I had to decrease the frequency of cranking, battery getting slow.
The van is directly in the sun so it was HOT today even with windows down.

 

[Rustyiron]

Throw a diesel SOAKED rag over the heavy screen under where the air filter sits, crank the motor until it fires. CAUTION; be prepaired to pull off the rag, keeping in mind that there is 444 cubic inches trying to suck it through the motor and it will "run away" and the key will not shut it down. DISCLAIMER; This solution was only explained to me and I have never had to resort to this, but usually if you get enough fuel in it to make it run enough to keep it's self going, it will work out the air pretty soon. Good luck.

 

[newbury]

Throw a diesel SOAKED rag over the heavy screen under where the air filter sits, crank the motor until it fires. CAUTION; be prepaired to pull off the rag, keeping in mind that there is 444 cubic inches trying to suck it through the motor and it will "run away" and the key will not shut it down. DISCLAIMER; This solution was only explained to me and I have never had to resort to this, but usually if you get enough fuel in it to make it run enough to keep it's self going, it will work out the air pretty soon. Good luck.

Thanks,
This ranks right up with inflating a tractor tire with ether and a match so it seats on the rim. I was just going to try and use a spray bottle of diesel/diesel kleen.

I might try it.

 

[newbury]

Success!!

Just kept on going out and loosening a few injectors, cranking for 20 seconds, tightening the injectors. Go inside, come out 10 or more minutes later repeat. SWMBO had started muttering that doing the same thing over and over with the same result, was a sign of being crazy.

Finally after cranking about 40 times I got fuel leak around one injector. Another 5 cycles and I got it around two, another 5 cycles and it's 4. Then it fired once, one cylinder.

A few more cycles and I took a spray bottle (old Fabreze bottle [the deodarant for men]) of diesel and gave it two misty squirts in the wire mesh. Cranked and it fired up ROUGH. Let it run for a while.
Time will tell but I'm hoping it's road ready.

 

[Highbeam]

Is this something you'll have to do every time you change the filter on a 7.3 IDI engine? Surely there is a better way or nobody would change fuel filters.

 

[newbury]

Seems it depends on how bad you let the air in. On other boards peeps have reported similar problems, having to crank a lot, but some only a little.
I think if I had just took off the filter, immediately put another on filled with diesel, cranked the injectors open, I probably would have gotten going in several cycles. With 30 seconds of crank and 10 minutes of rest it still would have taken a while.
But I had not changed the filter before, it had been done at shops. Whoever put the last one on had tightened the water drain down so tight I had to put it in a vise and use a big wrench to get it off. So by then I just took the night off. Everything then had plenty of air.
Another problem is just getting to the injectors, it was a bear to crack the the two just back from the front and their was no access to the front two. Remember it's a van.

 

[Highbeam]

Just a crappy system then. My tractor has no such problem with air in the system and it is a rotary pump too. Then my truck with the 7.3 powerstroke requires no such efforts, just put it on and start the truck.

Having to put a wrench on the injectors for regular maintenance means the system has a bad design.

 

[crashz]

There are better ways.

Next time, after fuel system is all buttoned up and before you crank the engine at all, place a hand operated vaccum pump (those brake bleed kits) on the system at any point at or after the fuel filter. My 6.2L diesel has one at the housing. If there is no other place, put it on the return line from the pump only. Pump until the fuel runs clear. Start as normal.

The other trick is to button the system up, and remove the shut off solenoid wire from the pump. Crank for 3 or so rounds of 20 seconds on/ 5 minsutes off. Put the wire back on the pump. Start. It may run a little rough, but should start. By doing this, the shut of solenoid will not allow the pump to fill the injector lines with air. Air goes back to the tank. This is a little more risky the first time because you don't know how many rounds of priming it will take to remove the air. You czan get an educated guess byt he schrader valve though.

I have disconnected the glow plug system and fired these on starting fluid as a lazy way to prime them, killing a worn out 6.9L IDI in the process, so I would advise against that.