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Oil Contamination With Fuel After Knight Sports ECU Upgrade

Old May 21, 2007 | 04:49 PM
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Oil Contamination With Fuel After Knight Sports ECU Upgrade

Ok from the top around a month ago car was fine, totally fine in everyway.

Got myself a knight sport ECU, Ex jap, 2nd hand item that was said to be off a mechanically standard car.

Put it on my car and noticable power increase, side effect it used loads of fuel, but i thought ok thats normal. idle was very rough too and smell of gas was very strong when idling.

Then when doing around 150mph on a military runway the oil pressure guage showed zero, so i got out. Taking the tip stick out i could smell the fuel in oil, the filler cap too had the same smell.

Drained oil and re-plen( the oil was very thin like water and smelt of fuel). Day or two later smell of fuel in oil again, Thought about the ECU and how rich it seemed to be running,

checked the spark plugs, The font set where normal, whereas the rear set where soaking, and a wipe with a white rag showed that the liquid on them was dirty like oil, not just pure fuel. Now I thought if the rotor is being drowned then this dirty colour could be carbon from poor combustion;.

I have since swapped back to standard ECU, runs very well again idles very nicely. Oil still has fuel smell but then i haven't chanced it yet.

also no gases are coming out of the oil filler cap.

you now know everything, What do you think? Can a rich mixture contaminate the oil? Or is this some sort of seal problem?

Last edited by tomoaac; May 21, 2007 at 04:55 PM.
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Old May 21, 2007 | 04:57 PM
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it can contaminate the oil becasue oil is being sprayed into the combustion chamber, unless you are premixing.
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Old May 21, 2007 | 05:16 PM
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It could be possible for the rich mix to contaminate oil if it is just flooding the chamber. I had a leaky injector problem for months that would cause similarly gas rich oil, but I did not have the same drive-ability problems with it. If the fuel is sitting in the combustion chamber, it can "wash" out the chamber and leak down into the oil eventually.

I would be more concerned with why your oil pressure was at zero? My concern would be that I oil starved something and caused some serious damage. Hopefully nothing serious was broken during that 150mph romp. (Which, by the way, sounds like lots of fun!)

What is this mystery ECU anyway, do you know exactly what it changed?
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Old May 21, 2007 | 05:34 PM
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Well the fueling must have been changed.

The boost guage was reading higher and the turbo did seem to be making more boost. But i always thought boost was set mechanically by the waste gate.

The car was quicker with the knight sport ECU, I recorded a 5 second something 0-60 with the car. 150mph was no problem with the head lights up as well, 160 possible with them down as i have done before.
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Old May 22, 2007 | 09:41 AM
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Sounds like the ECU is very poorly tuned. It's running way too rich.
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Old May 22, 2007 | 12:59 PM
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what injectors is this tuned for?
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Old May 23, 2007 | 06:38 AM
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So guy's what i really need to know is, is it the rich mixture causing fuel in oil or could it be something to do with my engines internals?

Basically do you thing my engine is good?
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Old May 23, 2007 | 09:31 AM
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Rich mixture.

If you continue to run around like this, then you are going to cause excessive wear internally due to the thinning of oil. You could end up seizing the engine.
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Old May 23, 2007 | 12:36 PM
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Yeah

I've already put the standard ecu back on and am now running standard again, runs better. Hoping that sorts out the thinning.

Still oil has some fuel left in, will this evaporate away like water does in oil or will i need to perform another oil change?
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Old May 23, 2007 | 12:40 PM
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Originally Posted by tomoaac
i need to perform another oil change
You answered your own question
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