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I have a 2000 f-250 7.3 powerstroke with 167,000 miles on it. I live in Texas and ever since the really cold spell we had in early February my truck has been having this problem: slow start, motor turns over for 10-20 seconds before starting (never done this before). When the motor does start, it idles fine. If I give it some fuel, the motor usually starts to bog down and blow white smoke around 2000rpms. If I back off, it will drop to around 800-900 rpms, sometimes die, sometimes not. Once it drops that low, it will recover and idle at normal rpm's if it does not die. As long as it is allowed to idle, it does not blow smoke. Smoke only comes out of the exhaust if I am giving it fuel. This only occurs if the truck has sat for an extended period of time (cooled off I guess). If I drive it 100 miles and turn it off, it will start right up with no smoke. Once the temperature gauge gets about a quarter of an inch above the C for cold, the truck runs fine, no smoke, no bogging down etc. Also, when running and warm, the truck retains all power speed etc.

Does anyone have any ideas as to what this might be? Glow plugs? Low oil? Injector? Compression
 

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Search GPR?
 

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had same problem when i had a leak at hpop and would run low on oil.

most likely you are low on oil. generally 2 plus quarts low for me is when it did it.

hope this helps.
to salty pop, where was your hpop leaking at? I have a bad oil leak i CANNOT FIND. My truck has leaked oil for a while while i have tried to locate it. Just recently trucked started to smoke more on start up and once warmed up all better.... Also oil leak got worse....
 

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the slow start is possibly another problem as well.

that part could be your starter.

i have put several on just for slow starts alone.

still believe you are possibly low on oil on the other.

give us an update when you can.

thanks
 

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Seth,

do you have alot of oil sitting in your valley behind the hpop?

check there first.

if the valley is staying full and you are having alot of leakage then your "O"rings on the hpop have most likely gone.

mine was so bad that i would run up to 5 qrts low a week until i installed new o rings.
 

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Hello im new to this cite. Im newer to the powerstroke world but ive done loads of research and read up on 7.3 PSD alot. The problem im having with my truck is a vibration at an idle and vibration when you rev the truck in park. I did brand new lift pump new fuel filter i did the tank pick up foot and new screens cleaned everything. The truck also smokes alot on cold starts ive done the whole glow plug system from the harnesses to the controler. Ive read alot about the injector o-rings failing. The truck has 262k miles on it. Should i try replacing the o-rings or is it more likely that its a dead or sticky injector?
 

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What you really need is a scan tool that will do a Cylinder Contribution Test (CCT). I'm going to guess that you have one or more dead cylinders. If you get codes from the CCT that indicates that, then follow up with a compression test. If that highlights a bad cylinder then do a leakdown test, putting compressed air into a suspect cylinder and listening for where the air is leaking out. If from intake or exhaust, that indicates bad valves, and if from the crankcase, it indicates bad rings or a holed piston. That will tell you how deep into the engine you might need to go.

You can tell if you have leaking o-rings that can be discovered by inspecting the fuel filter for evidence of oil backing up into the housing, or by pulling the valve covers and watching for oil coming out around the injector(s).
 

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What you really need is a scan tool that will do a Cylinder Contribution Test (CCT). I'm going to guess that you have one or more dead cylinders. If you get codes from the CCT that indicates that, then follow up with a compression test. If that highlights a bad cylinder then do a leakdown test, putting compressed air into a suspect cylinder and listening for where the air is leaking out. If from intake or exhaust, that indicates bad valves, and if from the crankcase, it indicates bad rings or a holed piston. That will tell you how deep into the engine you might need to go.

You can tell if you have leaking o-rings that can be discovered by inspecting the fuel filter for evidence of oil backing up into the housing, or by pulling the valve covers and watching for oil coming out around the injector(s).
The truck runs better after it warms up. Still does have a vibration at idle. I tried the trick of unplugging the ICP and for a split second the truck smooths out but then it goes right back to running rough. Is that possibly a bad sensor? Or is it more likely that when i unplug it he fuel pressure slightly goes up and its sealing the bad injector o-ring but then running bad again. The truck had been sitting for quite awhile when i got it. Ive already replaced the fuel filter once should i pull it and check to see if its black?
 

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Welcome to the TDS forum.
Did you happen to test your GP system after you replaced it with all new parts?
Do you recall the brand of GPs you installed?

EDIT:
I missed the part where this occurs until it warms up. Scratch my questions above.

Question for the members, I know the proper procedure for o-rings is to visually check the fuel filter but is it possible to drain a bit of fuel bowl diesel into a glass jar and look for discoloration instead?
 

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You might be able to see some discoloration in fuel drained into a jar.

@kcseattlew
Since it runs better after it warms up, your issue might be reduced clearances in the injectors due to wear that cause "oil stiction" when cold.
There's a kit available to shim the armature plates to fix that.
Big Horn did a nice write-up on shimming injectors HERE.
 

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Welcome to the TDS forum.
Did you happen to test your GP system after you replaced it with all new parts?
Do you recall the brand of GPs you installed?

EDIT:
I missed the part where this occurs until it warms up. Scratch my questions above.

Question for the members, I know the proper procedure for o-rings is to visually check the fuel filter but is it possible to drain a bit of fuel bowl diesel into a glass jar and look for discoloration instead?
I used motorcraft glow plugs. I can definatly drain some and look at it otherwise i was just gonna pull the filter and see how it looked. I put a new Fram in it when i did full tune up. i do recall when i did the oil change seeing some odd contaminates in the oil is that possible that its diesel fuel?
 

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You might be able to see some discoloration in fuel drained into a jar.

@kcseattlew
Since it runs better after it warms up, your issue might be reduced clearances in the injectors due to wear that cause "oil stiction" when cold.
There's a kit available to shim the armature plates to fix that.
Big Horn did a nice write-up on shimming injectors HERE.
It runs slightly better and smoke clears but ive compared it to another 7.3 and the vibration at idle is noticable. I already did the High pressure cross over line because ive heard that better distributes the oil to the rails. The idle is much quieter under the hood.
 

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What year is your truck?
 

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The truck needs a new transmission and i bought a parts truck thats got a brand new built one with stage two shift kit billet aluminum torque converter. its wrecked truck i bought from my uncle its got a good running engine in it but i was thinking about trying to repair the one in my truck before doing complete powertrain swap. As it is ive done alota work to my current engine. Is it worth shimming the injectors as well as new o-rings or is it better to just replace them?
 

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The shim is just a "band-aid" fix for worn poppets. If all else is good and you just have the worn poppets, this will allow you to continue using your injectors awhile longer before replacement. I did mine at 206k miles, and now have 217k miles on them. Doing the shims really helped cold starts. I'm hoping I can get a few more miles before having to do injectors...they are original AFAIK.
 

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The shim is just a "band-aid" fix for worn poppets. If all else is good and you just have the worn poppets, this will allow you to continue using your injectors awhile longer before replacement. I did mine at 206k miles, and now have 217k miles on them. Doing the shims really helped cold starts. I'm hoping I can get a few more miles before having to do injectors...they are original AFAIK.
Makes sense. I just did the stiction treatment. I bought the hotshots secrets and she seems happier at idle. Im waiting for tomorrow morning and try to start again. I will probably still do injector o-rings. it still has a slight vibration at idle and a vibration driving down the road. ive verified that its not the driveshaft as i sent it out had it rebuilt and balanced. I do remember doing the first oil change after buying it and seeing some type of contaminate in the oil. You could see a substance seperating from the oil itself. That now leads me to believe that theres a leaking o-ring allowing fuel into the oil.
 

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I do remember doing the first oil change after buying it and seeing some type of contaminate in the oil. You could see a substance seperating from the oil itself. That now leads me to believe that theres a leaking o-ring allowing fuel into the oil.
Injector o-rings will put oil into the fuel return and back into the tank, and very little fuel into the oil. Your oil level would drop more than normal as well. Fuel in the oil would be something more serious like a broken injector nozzle and fuel running by the rings.
But if what you saw was separating from the oil, it's likely not fuel, which would mix in the oil and stay mixed. Coolant would separate. A used oil analysis at your next oil change would tell you if you have fuel contamination or coolant contamination.
 
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