VS L67 running rich on drivers bank

160 And 8192 Baud Aldl
bignutzzz
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Re: VS L67 running rich on drivers bank

Post by bignutzzz »

Im still doing my head about this, I noticed the wires on the injectors were split and frayed so i reterminated them with new plugs. Didnt fix the issue. I also checked the timing was set up fine. I earthed the O2 sensor and heater circuit to the back of the head (only the drivers side to see if it made any difference). It made a noticeable improvement to idle but did not fix the misfire. It does run really smoothly on 5 cylinders though lol. LTFT readings on the drivers side havent changed at all. Although when i changed the Drivers side O2, i was able to get the STFT down to 0 on the drivers. I also just noticed im getting high readings on the wideband o2 injector feedback line (b12). Im over my head at this point lol. im starting to think it might be a cracked head or inlet at this point. Maybe number 2?
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Re: VS L67 running rich on drivers bank

Post by Charlescrown »

Using my phone with small characters so forgive me if I double with info. I think from memory your ecu can do a power balance test which will identify the offending cylinder. From my experience and what you say it's a definite miss most likely mechanical.
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Re: VS L67 running rich on drivers bank

Post by vlad01 »

I've had 2 engines with a miss that was low compression. One was a 5L that had burnt out a valve and bent a few pushrods. Another was a 4L Ford that the rear piston wore into the bore sideway somehow and there was something like a 5-6mm clearance on the right side of the bore with the left side of the piston digging under the deck.

The usual checks came empty handed and only a comp test would have shown the issue, but I didn't have one then. But I knew it was mechanical as both injector and spark didn't change the result.
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bignutzzz
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Re: VS L67 running rich on drivers bank

Post by bignutzzz »

Charlescrown wrote:Using my phone with small characters so forgive me if I double with info. I think from memory your ecu can do a power balance test which will identify the offending cylinder. From my experience and what you say it's a definite miss most likely mechanical.
Ive been trying to find some form of power balance data but i really dont know what im doing lol. Hard work trying to make sense of a lot of it. How does one check the power balance? Ive been using tunerpro.
bignutzzz
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Re: VS L67 running rich on drivers bank

Post by bignutzzz »

vlad01 wrote:I've had 2 engines with a miss that was low compression. One was a 5L that had burnt out a valve and bent a few pushrods. Another was a 4L Ford that the rear piston wore into the bore sideway somehow and there was something like a 5-6mm clearance on the right side of the bore with the left side of the piston digging under the deck.

The usual checks came empty handed and only a comp test would have shown the issue, but I didn't have one then. But I knew it was mechanical as both injector and spark didn't change the result.
Compression came back ok. Got myself a leak down tester yesterday so will see how we go.
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Re: VS L67 running rich on drivers bank

Post by bignutzzz »

pink wire on the oxy sensor plugs, is this supposed to have a short to ground???
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Re: VS L67 running rich on drivers bank

Post by vlad01 »

Pink should be 12V. Maybe you used the continuity on your meter while it had power? I know some meters will shower power as a short.

What cam has it got? original stock or an aftermarket one?
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Re: VS L67 running rich on drivers bank

Post by Charlescrown »

Sorry I should have clarified the power balace test. Best method is with a scantool and it's just a matter of pressing a button and it then goes thru a full test on all cylinders then displays the results. Bush method is to disconnect eaach injector when the engine is idling noting the drop in revs. The bigger the drop the stronger the cylinder so when you see little or no drop thats the cylinder causing the problem A cylinder leakage test is good but all it tells you is how well the cyliner is pressurising. I there are issues like worn cam lobes it shows up as good. I run 4 basic tests on an engine to determine condition. Compression, cyl leakage, power balance and exhaust gas analasis but the first 3 should clearly tell you what cylinder is the offender and an anaysis will allow you to determine just what is causing the problem.
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Re: VS L67 running rich on drivers bank

Post by vlad01 »

We had an XF falcon when I was young that had a miss and everything showed up fine, comp and leak down were fine. The mechanic found a wiped lobe on the cam.

The old 253 and 308s used to do it without fail too.

With roller cams this is very unlikely but the reason I am asking about the cam's origin is that I have heard of Crow cams grinding cams with one or more lobes with wrong timing compared to the rest of the lobes by mistake.
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bignutzzz
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Re: VS L67 running rich on drivers bank

Post by bignutzzz »

vlad01 wrote:Pink should be 12V. Maybe you used the continuity on your meter while it had power? I know some meters will shower power as a short.

What cam has it got? original stock or an aftermarket one?
Definitely a short to ground on the pink wire. Was definitely set to resistance. Also no power as the sensor is unplugged. I unplugged both O2s to make sure. Also i compared to my other ecotec in the shed which didnt give me anything on the pink wire.
Just a stock cam.
Last edited by bignutzzz on Fri Apr 01, 2022 6:25 pm, edited 1 time in total.
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