***Changed some 7.3 injectors, now wont start, WTH***

altoids

altoids

Well-Known Member
Joined
Oct 24, 2007
Location
Archdale
Had my SES light come on two or three weeks ago. Bunch of question asking and visit to Ford dealership later I get to this point. Tech said #5 injector was showing bad. Ohmed them out showed good yada yada. Took valve cover off, harness still had good connection. Started disconnecting each injector. #1 & #5 made no change in how the engine was running when I unplugged them, #3 & #7 made the engine stumble when unplugged. So I came to the conclusion my #1 & #5 injectors are bad.
Buddy had some spare injectors that he removed from a good engine (AD code, mine are AB) he said I could try. Took out #5 first and let oil/fuel run into cylinder. Waited a bit to let mixture empty out of rails. Cleaned out injector cup and used a vacuum pump to suck out most of the oil in cylinder (got about 15-17 ounces out). Coated new seals with oil and installed my "loaned" injector continued on to #5 did the same (barely any oil ran into cylinder). Turned crankshaft over by hand three times (moved freely). Took fuse #30 out (so it wouldn't fire up) and turned engine over for two 5-7 second cranks (turned freely, no hydro lock going on ). Changed out all four glow plugs on passenger side at this time. Put fuse #30 back in and attempted to start. Probably tried cranking it 12-14 times over a 2-3 minute period (no more than 15 seconds for the longest attempt). Batteries started dying so had to quit trying.
How long before this thing fires up? Any thing I can do to purge the air out besides cranking on it (I assume the air in the system is why its not starting)? It's always fired up pretty quick so I'm stumped. HELP!
 
there is a plug on the back of each head 1/4 allen wrench i think crack it to purge air out of fuel line. p.s you will get wet it's alot of pressure. mine done the same thing it was the wireing harness.
 
Charge the batteries and keep trying. It'll have to bleed the air from the high pressure oil system too before it'll crank. The 6.0s use a similar system, I've had to crank my 6l for 5-7 minutes before after changing the hpop.
 
Other tip I learned from the diesel mechanics at the dealer I use to work at, once it fires up and runs do not shut it down for at least 20-30 minutes. Check your oil too.
 
After it cranks and you check for leaks, let it warm up some etc. Before you park it and shut down, take it out and make 5 to 7 runs at or near full throttle in a lower gear. The extra demand on the high pressure oil system will help purge air. I've seen 6.0 and 7.3s not start if cranked and shut down right away, you'd have to do more cranking.
 
Well hooked charger up. Disconnected UVCH at cover for both banks. Filled HPOP reservoir to the top. Turned engine over for 20 seconds, waited about 45 seconds, turned it over again for 20 seconds. Hooked UVCH's back up. Let batteries charge up some more. Turned it over, oil pressure gauge started to move after about 5 seconds. After 10 seconds it started to attempt to fire then after 15 seconds it fired on up. Yeeeaaaahhhhh.
Appreciate all the help guys.
 
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