If a stuck nozzle or 'leaking injector' was leaking enough to not start, aka not be building enough rail pressure, OP would be seeing a lot of thick grayish white smoke coming from the exhaust. Also you would have an obnormal cranking due to an almost hydrolock. The engine would have a sharp bucking.
Cranks but don't start
- Thread starter Bigsexy
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IHPowerstroke7.3
New member
I believe he meant air leaking into the injector, like combustion gas getting into the fuel system. But yes, if an injector was leaking fuel that bad, it probably would hydro lock. If its leaking that bad, it also shouldn't build rail pressure easily. Which makes me wonder if the sensor is reading correctly. Its no different than a biased ICP sensor on a 7.3, 6.0. Might read pressure, doesn't mean its right.
IHPowerstroke7.3
New member
Good question, I've never seen it happen. But apparently it can happen, because Ford has test procedures for it. I believe they can leak through a failed copper washer and leak into the return side and somehow cause issues. But if a copper washer has failed, likely have other symptoms appear first.
webb06
Active member
so is the tach moving when cranking? does "sync" pid on ids show yes? check the low side fuel pressure just for fun.
i would even go as far as letting the glowplugs cycle off and using ether to see if it'll fire. when you swapped the ecm i suppose you removed the tuning and installed the tuning back into the new ecm?
i would even go as far as letting the glowplugs cycle off and using ether to see if it'll fire. when you swapped the ecm i suppose you removed the tuning and installed the tuning back into the new ecm?
Powerstroke Man 6.4
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This is what I suggested, but instead of using ether use brake clean. I had a similar situation happen to a buddies truck the other week, died out of nowhere and didn't want to start (had 1/4 tank non stop cranking and RP was 5500 no start. (had sync and all the pids were normal no codes).
Towed it to fuel station and filled up, still didn't want to start, cracked open the fuel bowl purged it, closed it used the schrader valve to do the rest. We had a steady stream of fuel still no start. (pids still normal, 5500 RP) decided to try brake clean down the intake couple sprays and cranks later boom it started.
Bigsexy
New member
All the sync and everything shows no problems but my buddy's thinking after checking actual mechanical pressures it's the hpfp. The computer is showing is 5500 psi but it's actually less then that and won't build anymore even though it shows it will build 10k
you have to be carefull with that rail pressure PID, there is desired and actual rail, some scanners will and wont read actual. Use a dash daq or Minimax to check actual rail rather than whatever else you are using.
Move from that and replace the sensor, you have done entirely too much work at this point checking compression. It wont just shut down on that. The ECM Thing I think you replaced that prematurely as well. Since you have had the cab off you need to check all the connections again on the ecm and the plugs under the master cylinder.
what kinda pressures are you seeing? That's a hell of a mechanical gauge to read over 5000 psi...
Move from that and replace the sensor, you have done entirely too much work at this point checking compression. It wont just shut down on that. The ECM Thing I think you replaced that prematurely as well. Since you have had the cab off you need to check all the connections again on the ecm and the plugs under the master cylinder.
what kinda pressures are you seeing? That's a hell of a mechanical gauge to read over 5000 psi...
Bigsexy
New member
I'm not sure, it's at my buddy's shop being I'm not equipped nor do I know what I'm doing trying to figure out what's wrong with it. I know when he did the ecm he went thru every connector and connection on the truck. He's actually been talking with Nathaniel that used to work at Elite about it trying to help him. My buddys been a mechanic for a while now and figured he'd have it running or know what's wrong with it right away and it has him stumped. My truck has an warranty I got the credit union offered me when I got my loan for my truck and they covered the ecm luckily. That's the only reason I took it to his shop because they won't cover anything if I do the work but they will thru his shop.
Bigsexy
New member
I'm not sure what he used to test the pressures but I'm gonna find out. I know my buddy's kit from kit has the stuff to test 10k but not sure how it all works
Bigsexy
New member
Replaced the hpfp yesterday and it builds a lot better pressure now but didn't fix the problem so I'm going to swap in new injectors today and hopefully that'll fix it. We're thinking when the pump took a dump it also trashed the injectors so I'm gonna replace them all with new Ford ones
webb06
Active member
You better check for metal in the lines and tank if you think the pump blew up. Or you'll be doing this all again.
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NathannialD
New member
Lol told you the pump wasn't the issue
Bigsexy
New member
No pump didn't go, I should have started with swapping injectors. I'll know today when the place I sent the pump checks it but pretty sure it was injectors the whole time. It's all good I was due for a new oil cooler and did heavy duty uppipes while the cab was up
Bigsexy
New member
I plan on running dual fuelers so worse case I keep the other k16 for that if it's good
Bigsexy
New member
I forgot she runs now with new injectors I appreciate the help
I Have seen more and more of that lately, good work
elrodalexander73
Member
The condition I have seen exhibited here is what we call needles hanging partially opened, DD15s exhibit this quite a bit, if you let them dry out during a cam housing reseal or something they can get stuck in the closed position and not allow the truck to start, it'll put out a small amount of smoke but only because it's allowing a small amount of fuel past, basically a dribble condition.. I've put in prolly 500 injectors in the past 4 years in DD15s cause of this as well as ISB's and the new ISX's too... This problem can be a bear to troubleshoot.. In the DDEC10 software you can monitor fuel mass and if it below a value of say 40 while cranking but you have adequate desired rail pressure the injectors have failed.. Common rail systems are tricky bastards at times.
Bigsexy
New member
Just an update, she ran for about an hour and we were back to square one. We pulled the tank and come to find out someone sugared my tank. So now I gotta replace it all again
