7.3 powerstroke problems

[LSx S10]

Whats up guys. One of the tow trucks at my work is misfiring and blowing white/blue smoke like crazy. It's a 2003 F-350 7.3L with 230k miles. It was running fine all last night, but this morning is when it started. Been doing some research and the symptoms are pointing to the UVC harness for the injectors and glow plugs. Its a decent sized job to get the valve covers off, so I want to make sure this is the problem. Has anyone dealt with this before? Is there a way I can check the connections without doing an injector buzz test? Maybe with an ohmeter?

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[SRT41320]

that smoke mean raw fuel coming out IIRC...sounds like a bad injector/driver

 

[daturbosix]

im not sure about testing it all but my friend has delt with 7.3 for a while now. id give him a call.. 630.405.9081, his name is tony.

 

[LSx S10]

im not sure about testing it all but my friend has delt with 7.3 for a while now. id give him a call.. 630.405.9081, his name is tony.

Thanks!

 

[byronchrisp05]

If you get a pin out of the IDM you can check all of your injectors threw the uvc harnesses from there.

Do you do you have a check engine light on?

Sounds to me like it has a bad injector but the only way to make sure and find out what cyl. is to hook a IDS up to it

Its really not that bad to pull the valve covers on them

 

[LSx S10]

I found a diagram of the 9 pin connectors by the valve covers. I checked for continuity and I didn't find any open circuits. All of the injector had about the same resistance values too. For now I am ruling out the uvc harness. I think your right, pretty sure its either a stuck injector or a bad o-ring. I am towing it over to my buddies shop tomorrow to run some tests. He's got an IH scan tool, should be able to get it figured out.

 

[Outlaw]

Sounds like an injector to me. Have they been done previously on the truck?

 

[CrunkMaro]

you have enough oil and oil pressure right

 

[CrunkMaro]

oh and yeah check with ohmmeter

harness should only be about 5 hours or so.

if you can, do a cylinder contribution test. remember, 8th injector is long lead, fires after 6 and uses same oil and sprays a lil more fuel to compensate for lower oil pressure
perdels should be <4%
8th one should be <5 if using old black CPS or <8 if using the new one


hollaa

 

[LSx S10]

oh and yeah check with ohmmeter

harness should only be about 5 hours or so.

if you can, do a cylinder contribution test. remember, 8th injector is long lead, fires after 6 and uses same oil and sprays a lil more fuel to compensate for lower oil pressure
perdels should be <4%
8th one should be <5 if using old black CPS or <8 if using the new one


hollaa

Oil was down about 2.5qt. Topped it off with no change. Fuel filter was 4 months old, this was replaced with no change. All fuses checked and were good.

We didn't get a chance to get the truck towed over to his shop yet. Should be doing that sometime this week when one of the other trucks has some downtime.

 

[CrunkMaro]

Oil was down about 2.5qt. Topped it off with no change. Fuel filter was 4 months old, this was replaced with no change. All fuses checked and were good.

We didn't get a chance to get the truck towed over to his shop yet. Should be doing that sometime this week when one of the other trucks has some downtime.

i've had issues with powerstrokes misfiring and riding rough with low oil, low oil pressure. fuel pressure is relative to oil pressure, and oil viscosity. thin oil and <12 psi i think knocks out fuel injectors. something liek that. oil pressure pressurizes fuel in injectors for fuel injection.

 

[LSx S10]

Ended up being a bad lift pump.