Injector swap
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Senior User
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Injector swap
My number 8 injector failed a buzz test, and the contribution test said it was bad also. So I plan on swapping it out. My question is what is the best way to prevent hydrolocking the motor, and what is the diameter of the glow plug hole. I plan on sucking the oil and diesel fuel that leaks down into the cylinder, but what size hose will fit thru the glow plug hole.
Trying to Gain Knowledge
Joined: Jun 2003
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From: Ezzell, TX
If jeffreyt chimes in, he can tell you. He pulled all of his this past weekend and changed injector cups and o-rings. I know that the mighty vac tube is to large, but a needle attachment should fit down in the cylinder.
Fleet Mechanic
Joined: Apr 2011
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From: Marseilles IL
My number 8 injector failed a buzz test, and the contribution test said it was bad also. So I plan on swapping it out. My question is what is the best way to prevent hydrolocking the motor, and what is the diameter of the glow plug hole. I plan on sucking the oil and diesel fuel that leaks down into the cylinder, but what size hose will fit thru the glow plug hole.
Postmaster
Joined: Apr 2012
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From: North Georgia
i used some semi rigid vacuum tubing i picked up at lowes...
mity-vac the bulk out... then ... with the glow plugs removed... spin the motor over by hand with a socket on crank pulley bolt a few times.... this is after the injectors have been reinstalled mind you...
after you manually spin it over a few times... with the 42 pin connector disconnected...
crank the engine for 15-20 seconds.
a bunch of oil mist will blow out...
wait about 5 minutes.
do it again...
repeat 3 to 4 times...
reinstall glowplugs...
hook up electricals...
start motor.
mity-vac the bulk out... then ... with the glow plugs removed... spin the motor over by hand with a socket on crank pulley bolt a few times.... this is after the injectors have been reinstalled mind you...
after you manually spin it over a few times... with the 42 pin connector disconnected...
crank the engine for 15-20 seconds.
a bunch of oil mist will blow out...
wait about 5 minutes.
do it again...
repeat 3 to 4 times...
reinstall glowplugs...
hook up electricals...
start motor.
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I brought my truck to a friend of mine that works at a ford dealer and he put it on there computer. On the contribution test the injector was misfiring. Then we buzz tested the injector and it was weak. What made me bring it to him was a weird vibration I felt at idle. What I'm looking for is the size of a glow plug so I know what size tube fits in the glowplug hole
Postmaster
Joined: Apr 2012
Posts: 2,613
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From: North Georgia
like 5/16 od. maybe a teensy bit smaller so you have wiggle room.
and i lied... it wasnt vacuum tubing i used... it was spray mister tubing... black and semi rigid... i made about a 30* bend about 3" from the end oriented to the lowest point i could get to in the cylinder.
and i lied... it wasnt vacuum tubing i used... it was spray mister tubing... black and semi rigid... i made about a 30* bend about 3" from the end oriented to the lowest point i could get to in the cylinder.
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Cargo Master
Joined: Oct 2010
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Was it actually weak or did it sound different? #8 has a little different sound than the other 7 because it should be a different injector.
If you are running the last gray cps they came out with, that could be your weirdness at idle, especially when warm.
I had 2 trucks at one time -a 2000 and a 2001. My 2000 does not like the latest gray cps. It would develop almost a skip type vibration flutter feel at idle. The 2001 did not care.
The 2000 started that from day one. I changed it back to a black cps and it went away. it is fairly common for these to fail cct test on #3 & 8 injector and nothing be wrong. Since I had a reference as to when it started, i could easily predict what the cause of mine was.
I am sorry to bring that up again. I want to say the hole is like 4 or 5 mm but someone else here probably has a glow plug they can measure the tip diameter on. I always just bar it over by hand and do it that way until the bulk is out and then spin with the starter like already mentioned.
If you are running the last gray cps they came out with, that could be your weirdness at idle, especially when warm.
I had 2 trucks at one time -a 2000 and a 2001. My 2000 does not like the latest gray cps. It would develop almost a skip type vibration flutter feel at idle. The 2001 did not care.
The 2000 started that from day one. I changed it back to a black cps and it went away. it is fairly common for these to fail cct test on #3 & 8 injector and nothing be wrong. Since I had a reference as to when it started, i could easily predict what the cause of mine was.
I am sorry to bring that up again. I want to say the hole is like 4 or 5 mm but someone else here probably has a glow plug they can measure the tip diameter on. I always just bar it over by hand and do it that way until the bulk is out and then spin with the starter like already mentioned.
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It failed buzz test I could barley hear 8 injector when it fired extreamly weak. So if I suck out most of the oil then turn it over by hand then disconnect both 42 pin connectors an crank motor with starter with # 8 glow plug removed an I should be fine
More Turbo
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From: cincinnati, oh.
chris
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From: Mesa AZ
If you want to be sure, use a socket on the crank and rotate the engine by hand after you have installed the injector but before you install the glow plug. 
Postmaster
Joined: Jun 2010
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From: Longview, TX
Ted is right, the mity vac hose was barely too big. I had just replaced my passenger fuel line, so I cut a piece of the old line that fit perfect. I didn't put the valve covers back on as I didn't want the oil to fall back down after it was contaminated. It wasn't that much anyway, because I vacuumed most of it out.
If you want to do one more test, you could visually check if its spitting oil before you remove it. Mine spit great and passed buzz test with flying colors. We noticed two didn't reach the same reading on the tac, but the more we ran it, the better they seemed. Just dry I assume.
Oh, I couldn't get the starter to turn the engine over with the solenoid. I just used the key. Pre 2002 solenoid is on the pass fender, 2002+ is near the starter.
Good luck!
If you want to do one more test, you could visually check if its spitting oil before you remove it. Mine spit great and passed buzz test with flying colors. We noticed two didn't reach the same reading on the tac, but the more we ran it, the better they seemed. Just dry I assume.
Oh, I couldn't get the starter to turn the engine over with the solenoid. I just used the key. Pre 2002 solenoid is on the pass fender, 2002+ is near the starter.
Good luck!
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