Erratic A/F Ratio under Cruise

Ok so I unplugged the logger, grounded the connector, so the timing should have been constant right? When I did that, the A/F jumped around still... This points to air or fuel, right?

Thanks!

Just checked voltage at the pump and seemed fairly solid at 13 volts. Check my original post for all details (not on my laptop right now).

I'm fairly confident the problem is related to the fuel system unless the wideband is acting goofy which I haven't been able to look at yet. I can also pressure test again but doubt that's an issue.

Any ideasa? May just spend the $80 in supplies to hook up my AFPR with gauge to see if that helps/how fuel pressure looks.

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Originally Posted by HLxDrummer

Well I tried unplugging the stock O2s tonight to no avail. Still jumps around a lot, just shifted slightly richer.

I'm beginning to think emanage, exhaust leak (doubt it), or fuel. I pressured tested not too long ago and everything was fine so I doubt that is the issue. My vacuum is also great which further disproves that theory in my eyes...

Should I get a fuel pressure gauge? I'll unplug the emanage sometime it's just cold and rainy right now and I don't feel like shoving cold hands through all the plastic toget to it while I'm upside down in my seat lol



XXEdit: Just shut off my car after driving it and turn the key back on so the wideband would operate and it was fluctuating from like 13:1 to 16:1. Now I know the wind is rushing into the tailpipe/etc. but do you think that indicates a problem with the exhaust/wideband? It is a few years old probably but not that many miles... It reads pretty steady during warm up and under engine braking..XX

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Where is your widebnd located?, that`s not normal behaviour at all if the key is on but the engine not running!. If I turn the engine off at stoich idle and re-key on so the wideband doesn`t loose power it will gradually drift lean (will take maybe a minute to hit 20:1), it never reads rich/lean/rich justs drifts lean..

I think you are tracing a wideband sensor or controller error!.

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Originally Posted by KeithMac

Where is your widebnd located?, that`s not normal behaviour at all if the key is on but the engine not running!. If I turn the engine off at stoich idle and re-key on so the wideband doesn`t loose power it will gradually drift lean (will take maybe a minute to hit 20:1), it never reads rich/lean/rich justs drifts lean..

I think you are tracing a wideband sensor or controller error!.

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Ya I thought that was strange... you still think that is the problem even if it reads normal during warm up and engine braking?

I wouldn`t trust it personally, what wideband is it? and where have you located the sensor?. If you think about it there`s no reason for it to read rich after leaning out with the engine stopped..

The controllers use a PID program to work out the AFR, the sensor could be chucking all sorts of odd numbers out but they will be averaged out by the controller, maybe why it only shows up with the engine stopped?.

Its an Innovate LC-1. I called them about it and they reccomended I recalibrate it and view the AFR through the digital output instead of analog. I need to pick up a jack and stands before I can calibrate though so well see. Any ways to test the O2 when I have it out besides checking with brake cleaner soaked rag?

The O2 is in the test pipe.

I was thinking maybe wind was blowing in the tailpipe with the engine off, diluting the air unevenly? After a while it'll go full lean, though.

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Originally Posted by HLxDrummer

Its an Innovate LC-1. I called them about it and they reccomended I recalibrate it and view the AFR through the digital output instead of analog. I need to pick up a jack and stands before I can calibrate though so well see. Any ways to test the O2 when I have it out besides checking with brake cleaner soaked rag?

The O2 is in the test pipe.

I was thinking maybe wind was blowing in the tailpipe with the engine off, diluting the air unevenly? After a while it'll go full lean, though.

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Test it with a lighter. Press the switch on your lighter to let fumes out but don't create a flame. Hold it up to the sensor and read the measurement.

This process is explained further in the LC-1 instruction manual.

Correction: it is not in the manual. I wonder where I saw this test outlined? I know it's in a wideband manual SOMEWHERE.

Regardless, you should try their suggestion on recalibration. Do a free air recalibration, reinstall, and view your AFRs via digital.

PDF to manual if you need it: http://www.innovatemotorsports.com/s...C-1_Manual.pdf

I will definitely try that, hopefully Sunday or early next week. Thank you!

Quote:

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Originally Posted by HLxDrummer

Its an Innovate LC-1. I called them about it and they reccomended I recalibrate it and view the AFR through the digital output instead of analog. I need to pick up a jack and stands before I can calibrate though so well see. Any ways to test the O2 when I have it out besides checking with brake cleaner soaked rag?

The O2 is in the test pipe.

I was thinking maybe wind was blowing in the tailpipe with the engine off, diluting the air unevenly? After a while it'll go full lean, though.

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My Zeitronix ZT-2 has never done that, before you pull the sensor out run the car at idle and after stopping it get someone to quickly cap the exhaust end and re-check, if it is still rich/lean/rich then something`s not right!. Also re-calibrating it will sort out any global AFR drift on the sensor but probably no the odd behaviour but it`s worth a go!.