Tiny Bubbles
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Tuned
Joined: Apr 2002
Posts: 328
Likes: 93
Tiny Bubbles
I have an 89 F350 4x4 7.3 IDI w/ 5spd. Been trying to remedy a hard start problem. So far I have replaced all of the glow plugs (beru), new controller (International), new O-rings / plastic caps / rubber lines to injectors, plugged the line going from filter housing to #1 injector. STILL HARD TO START even in warm weather! Yesterday I changed the fuel filter and after changing I started the engine and was looking for leaks when I noticed "tiny bubbles" around the glow plugs. Anyone ever see this? The bubbles were not constant. They seemed to surge like maybe every time an injector delivered fuel.
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
The small bubbles could be lost compression via the threads/face seal of the gp. The gp torque is 12 ftlbs or 12th of a turn more after bottoming. If the previous GPs were leaking there could be a carbon buildup on the mating face of the block/GP.
Re the air intrusion check the steel line seals on the 2 lines, 1 from lift pump to filter, the other filter to IP. There is a seal under the cap nut........
Visit....... http://www.intellidog.com/dieselmann/idi.htm for good info and the parts list for the seals.
Re the air intrusion check the steel line seals on the 2 lines, 1 from lift pump to filter, the other filter to IP. There is a seal under the cap nut........
Visit....... http://www.intellidog.com/dieselmann/idi.htm for good info and the parts list for the seals.
Tuned
Joined: Oct 2004
Posts: 250
Likes: 6
From: new york
Sounds like you have chased down most of the common problems, I would probably check fuel pressure next or just change the lift pump, they do get weak over time. How many miles are on the engine, My first 6.9 had tons of miles on it, I had to keep it plugged in even in the summer, the compression was so low it didn't hardly sound like a diesel. I had friends with 7.3's that would say "what did you do to make it run so quiet". I finally had to rebuild it. Good luck!
Postmaster
Joined: Jun 2003
Posts: 2,656
Likes: 5
From: shepherd
i also hear that the stock water seperator leaks air in. i am also looking for an air leak. i replaced the hoses on the injectors and o rings. removed the line like you and the seperater was already bypassed. next i am replacing all the fuel lines. it's going to suck.
Lead Driver
Joined: Jan 2005
Posts: 7,782
Likes: 221
From: Huntington Indiana
From the fuel tank. Follow both fuel lines along the frame. Look for rusting of lines. You could have an air leak there. I found mine on my 93 under a hold down clip on the frame. Bubbling is another story.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
I have seen that before on high mileage engines, and I do believe it was fuel. The amount was so small you could not tell. But it was enough to see bubbles.
Makes you wonder if the injector spray pattern is correct.
Makes you wonder if the injector spray pattern is correct.
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Tuned
Joined: Apr 2002
Posts: 328
Likes: 93
It has 153,000 miles on it and I'm confident that is correct since I bought it from the original owner. The lines I replaced between each injector had grey paint on them so I assume they were original. This truck runs absolutely great "after it starts"! Good power, no smoke, uses/leaks 1-2 quarts of oil between changes (5000 miles), and good fuel mileage (20+ on trips). The hard start problem is starting to get irritating. I'm worried now that a starter replacement is in my future $$$. One thing I forgot to mention (maybe not important). The kit I bought (stanadyne) containing the lines for between the injectors and the O-rings, also had a set of copper colored washers which I did not install. I assume they go between the head and the injector and will have no effect on the hard start problem.
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Tuned
Joined: Oct 2004
Posts: 250
Likes: 6
From: new york
The one thing that many owners do that seems to cancel out all air leak trouble and is fairly cheep is to install an electric fuel pump, that will preasurize the fuel system before you start cranking. Even if you just do it as a test to see if air is your real problem.