Type 1 in VL NA OEM N/band 02 sensor on 0 constantly

nanook · Post by **nanook** » Thu Sep 24, 2009 10:07 am

My o2 was just a straight line a while back it seemed to start cycling again after I loaded a new version of the software although it could have been a coincidence.

Matt: Regarding the comments you made re: the weird 0-5v maf and rpm spikes and the zenner diode's performance.

Do you have any update on this?

Matt · Post by **Matt** » Thu Sep 24, 2009 5:44 pm

yes, one of the forum 'Hal' users this week PM'd me regarding another method of dropping the MAF voltage and has traced out the schematic for the MAF section of this board, including measuring resistor values

His suggested modification involves reversing the current MAF modifications and removing pin 14 from A/D converter board on the RB30/VG30 board.

I did the mod this week and measured and all looked okay from a input/output display point of view, but one thing I didnt check is if the logged values were being offset by the address file entry. Checking that out tonight

This basically would still use the opamp to provide buffering/filtering and hopefully avoid those nasty spikes I'm seeing on the RB30. Will try it out this weekend and test over the following week

bachig24u · Post by **bachig24u** » Thu Sep 24, 2009 6:50 pm

Matt, I'm really keen to see the outcome, the MAF is occasionally hitting 5.1v and dropping to 0v all in about .5 seconds in my latest logs.
A dry joint in the Maf probably wouldn't cause the hugh swing. but maybe a varying reference voltage or saturated gate on a component might.

Hal · Post by **Hal** » Thu Sep 24, 2009 8:28 pm

Matt wrote:....removing pin 14 from A/D converter board on the RB30/VG30 board.

Matt did mean pin 14 of the op amp daughter board.
The pin numbers are silk screened on the main pcb at each corner of where the daughter board pins solder in [1, 11, 12 and 22]
Will also be testing this as part of an upgrade on my nephews VLT soon[/u]

nanook · Post by **nanook** » Fri Sep 25, 2009 3:42 pm

Re: my earlier post

This has happened for me for a long time, spikes up or down.
Both rpm and maf, interestingly the zeitronix unit also logs rpm and feeds this to nistune so I am able to log both rpm's.
the zeitronix log does not spike only the consult rpm and maf spikes hi or low.

I'm on hcr32 with z32 maf so there is no maf mod involved in my setup.

Matt · Post by **Matt** » Fri Sep 25, 2009 3:59 pm

sorry mean pin14 on the opamp board, not A/D converter chip

nanook - this was a Type 1 section which is why I got confused. You may be a problem with your R32 ECU or CAS if its doing that.... have you tried another CAS or even another ECU?

given that you are logging valid RPM with the zeitronix from the same CAS output would point more to an ECU issue where its 'interruptions' of the CAS signal are being missed or in worst case code corruption in the board causing invalid data to be reported

how frequent is it? does it happen with the factory ROM chip installed? I think you provided me with the 04U12 ROM image to do an ENT file this for your board if I remember correctly?

given it isnt dropping the consult connection whilst it is occuring and consult is sending that information about the CAS signal to Nistune and then we log it means that the ECU CAS RPM signal is going out of range for no reason

are you getting crank angle sensor faults? you might not be if a code problem. do you get this with factory ROM chip installed (if that is possible with your current setup)

Matt · Post by **Matt** » Sat Sep 26, 2009 1:22 am

potential fix regarding MAF voltage spikes
viewtopic.php?p=7916

bachig24u · Post by **bachig24u** » Sat Sep 26, 2009 10:44 am

I'll get this done this weekend post some new logs. Thanks

bachig24u · Post by **bachig24u** » Thu Oct 15, 2009 10:59 am

Matt,
I've performed the opamp cct mod changes to the ecu as described in the doco. left the zener in there although it probably shouldn't need it unless the afm goes really awall.

Fault resolved. You can permanently add the opamp board changes to the install doco.

I noticed a slight change in afm output by approx 200mV but its minor and very little if any adjustments were required to compensate.

bachig24u · Post by **bachig24u** » Mon Oct 19, 2009 9:33 pm

Hi Matt,
I lowered the NB02 sensor temp from 205 to 50 today and clicked the feedback flag again in the hope that several beta's later I would see an output displayed in latest version but to no avail.

the NB signal is affecting the afr's in the blue zone but just no display in Nistune.

Any other idea's to resolve this one?

nanook · Post by **nanook** » Fri Oct 23, 2009 4:20 pm

Here's what I have tried so far.

Changed CAS (rpm still spikes, log taken in tuner mode)

Tried doing a 30min log in stream mode and it was totally clean not one rpm spike?

If anyone can help me figure this out would be much appreciated.

Matt · Post by **Matt** » Fri Oct 23, 2009 4:49 pm

tried another ECU?

nanook · Post by **nanook** » Fri Oct 23, 2009 9:49 pm

I would like to try another ECU but I don't have one at this stage.
I am going to try a eprom with my current tune next and see how that goes.
If thats no good then I will get another ECU and try that.

Cheers Matt

Thevlguy · Post by **Thevlguy** » Sat Oct 24, 2009 10:02 am

i get those rpm spikes aswell, mine will spike and drop out, happens on the odd occasion, i put it down to the CAS or interferance

bachig24u · Post by **bachig24u** » Sun Jan 03, 2010 7:25 pm

May help to Clean, recrimp, replace earth wiring.
Some of these cars have loose, coroded, or greasy connectors.

Monitor Battery Voltage and see if it's related to an Alternator Fluctuation. Sometimes a leaky spark lead or a bad plug can cause wierd spike issues. I've found this increase with when Plugs are starting to breakdown or leak. Sometimes car runs fine but spikes increase in logs.

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