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7.3L Rough Idle/Knock, White Smoke when Cold, Loss of Power

10928 Views 17 Replies 4 Participants Last post by  cjayl1
-Rough idle/distinct knock that is worse when engine is cold
-Lots of white smoke on cold start (unplugged)
-Some white smoke when plugged in​
-Strong smell of diesel at all times
-Loss of power
-Terrible fuel mileage

1) Excursion was filled with gasoline accidentally
2) Excursion was taken to diesel shop who put in:
-New OEM injectors​
-Fuel filter​
-Blew out all fuel lines​
-All new glow plugs (unrelated to gas incident)​
3) The truck ran great for a few days, but I ran it low on fuel to clear any gas left in the system, which led to it stalling
4) I filled it with diesel and it started fine, but idled slightly rough
-Also had battery light come on intermittently​
5) I replaced the alternator after having it confirmed to be bad
-No change in idle​
6) I drove the Excursion for months and the idle progressively got worse
7) I did research and found that the ICP could be the cause
-ICP had oil in connector (meaning bad), so it was replaced with OEM ICP and pigtail​
-This quieted the idle, but the knock was still obvious​
Throughout this time, the truck would smoke white at first startup of the day and smell strongly of diesel
-Lots of smoke if unplugged, until warm​
-Less if plugged in, but still some initially​
8) CPS was replaced with BWD one from O'Reilly, as it is a simple and cheap thing to try
-This made the engine run terribly, so I thought I got a bad CPS​
9) Got another replacement BWD CPS and installed it
-Made it run terribly again, so re-installed OEM one​

So, this is where I am now. I have a rough idle and distinct, rhythmic knock that is worse sometimes than others, but consistently gets better as the engine warms up. I have white smoke on start. I can smell diesel at all times if I'm outside of the cab. I'm getting horrible fuel mileage and have a loss of power.

-Freshly changed oil/oil filter
-Have an oil leak that I can't trace, but always keep it topped off
-I have a TS Performance 6-pos. chip installed
-I do not have access to a scan tool with live data

Does anybody have suggestions on what to check next?
Could there be other things that the gas could have damaged that weren't replaced?
Does anybody know why it would run substantially worse with a new CPS?
-Could a new CPS amplify an existing problem?​
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1 - 2 of 18 Posts
Pop your oil fill cap while its running. Does it have a lot of blow by? If so you have a washed/dusted cylinder which would explain your knock.

Sent from App
Maybe you still have some gas in the system? Water?

Sent from App
1 - 2 of 18 Posts
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