flat afr and rpm drop in log file

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flat afr and rpm drop in log file

Postby erlend » Thu Nov 16, 2017 3:38 am

Hi

This is my first post here, so please refer me to the right topic if this is the wrong one.

I have a range rover classic with a 4.6L V8 from a newer p38 range rover.
Ive done the engine swap and wiring myself, learning by trail and error=)

4.6L V8
Microsquirt MS2
Quad spark
LC-1 wideband

Ive started by manually typing in afr table and ve table from http://www.britishv8.org/mg/curtisjacobson.htm
It’s the closest reference ive found to my engine top and size.
The engine starts and pulls ok, but at wide open throttle it pulls until higher rpm, then it starts stuttering.
When I look at the log file in megalogviewer I find two issues.

1 the afr goes up and down at a few shorter periods, but mainly it’s far too flat to be believable. What can cause this?

2 at wot with high rpm, when it stutters, the log file shows a dramatic drop in engine rpm. From 3000rpm to 150rp and back to 3000rpm again in seconds. What can cause this?

I tried uploading screenshots of the logfile, but get in reply that the Board quota has been reached. Is there another way of uploading screenshots?
I tried uploading the msl file, but its too big.

Regards
Erlend Eidsaa
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Re: flat afr and rpm drop in log file

Postby LT401Vette » Thu Nov 16, 2017 6:13 am

It is usually preferable that you upload actual msq's and log files instead of pictures.
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Re: flat afr and rpm drop in log file

Postby rickb794 » Thu Nov 16, 2017 10:20 am

For clarity

You have either a MicroSquirt or you have an MS2 they are different animals.
Different firmware and different manuals.

Curtis' install used a MS3 which is only somewhat transferrable to MS2/MicroSquirt usage.

Also use only Extra manuals for installs using Extra Firmware.
These can be found at the top of the page "Quick links".
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Re: flat afr and rpm drop in log file

Postby erlend » Thu Nov 16, 2017 12:59 pm

Hi. Thank you for your qiuck replies.

I have tried to upload msq and msl, but the webpage tells me that its not allowed to upload due to the board quota has been filled up..
Is there a nother way of sending the files?

I have the miqrosquirt module with what i believe is the latest update.
I thought the name of the software was ms2 or ms2 extra, but might remember this wrongly.

The only values i have transfered from Curtis is the afr target map and ve map.
The rest of the values i have dailed in manually from the info i have gathered online about my engine, injectors and sensors.
The default maps in tuner studio made the car drown with fuel.
With the maps from Curtis, the car runs allot better, but stutters at wot.
It makes sense as Curtis has a smaller engine, so his ve map is making my car too lean.
The afr map should be fine, but the ve map at wot needs to change.

This brings me back to my original question.
If i understand a bit more about why the afr reading is flat, and why megalogwiewer shows that my engine goes from 3200rpm to 150rpm when i experience these stutters at wot, it would be much easier to know how to change the ve map.
Im tempted to just start adding fuel as i did with my old carb bikes, but was really looking forward to do this a bit more scientifficly this time:)

Regards
Erlend
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Re: flat afr and rpm drop in log file

Postby erlend » Fri Nov 17, 2017 3:40 am

Finally manged to upload some files.

See attatched msq, msl and screenshots.

Any suggestions to what couses the two issues would be greatly appreciated!

Regards
Erlend
Attachments
EE_RRC_R01.msq
msq.
(119.09 KiB) Downloaded 19 times
2017-11-15_19.44.26.zip
msl. Had to zip as it was 1.5mb
(162.67 KiB) Downloaded 4 times
zoomed in.JPG
screenshot zoomed in on rpm drop
zoomed in.JPG (447.52 KiB) Viewed 250 times
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Re: flat afr and rpm drop in log file

Postby grom_e30 » Fri Nov 17, 2017 4:37 am

what wire from the lc1 did you connect to the microsquirt?

as to the rpm drop you have sync loss your losing the rpm signal to the ecu, can you take a tooth log of it losing sync? if it is a vr sensor it will more than likely mean you need to add a shunt resistor across the vr sensor wires.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
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Re: flat afr and rpm drop in log file

Postby erlend » Fri Nov 17, 2017 5:04 am

Tanks for the suggestions.

The car is at a workshop i only have access to once a week, so ill have to save up suggestions and try them all out that day.

I used the wire spesified in the lc manual, ill check the colour.

As to the rpm signal loss.would this also explain the stuttering at high rpm with wot?
It could mean that its not lean, but the ecu stops the fuel as it believes the engine has stopped?
Sounds scary for the engine, but then again its only very short stutters.
Ill try to figure out how to take a tooth log next time.
Insulalting the cable seems to be a good suggestion if this cable plays such an important role.

Regards
Erlend
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Re: flat afr and rpm drop in log file

Postby grom_e30 » Fri Nov 17, 2017 5:18 am

if the ecu misses a trigger wheel tooth or detects an extra one, it declares a sync loss, when this happens the ecu will cut the sparks and fuel & turn off the fuel pump until it re syncs up with the trigger wheel, it feels like you have hit a rev limiter or bad misfire usually.

there are 2 outputs on the lc1 by default one is a wideband output 0-5v and the other simulates a narrow band sensor output. you can plug directly in the the lc1 and use there software to read what the lc1 is reading to check as well.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
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Re: flat afr and rpm drop in log file

Postby rickb794 » Fri Nov 17, 2017 7:59 am

erlend wrote:I have the miqrosquirt module with what i believe is the latest update.
I thought the name of the software was ms2 or ms2 extra, but might remember this wrongly.



Again for clarity

A MicroSquirt Module and a cased MicroSquirt are 2 different animals
They also do not share firmware.

A MicroSquirt Module is furnished as a white circuit board that is usually plugged into an adapter board on which are the necessary connectors and accy circuits needed to complete a setup.
A MicroSquirt is a cased unit with an Ampseal connector, there are 2 versions made a v2(obsolete) and a v3.

Loading the wrong firmware can produce unexpected results.
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Use only these manuals http://www.msextra.com/manuals/
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Re: flat afr and rpm drop in log file

Postby rickb794 » Fri Nov 17, 2017 8:02 am

erlend wrote:Hi. Thank you for your qiuck replies.

I have tried to upload msq and msl, but the webpage tells me that its not allowed to upload due to the board quota has been filled up..
Is there a nother way of sending the files?



This was a board problem and has been fixed.

</Captain Obvious>
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Re: flat afr and rpm drop in log file

Postby grom_e30 » Fri Nov 17, 2017 9:31 am

rickb794 wrote:Again for clarity

A MicroSquirt Module and a cased MicroSquirt are 2 different animals
They also do not share firmware.

A MicroSquirt Module is furnished as a white circuit board that is usually plugged into an adapter board on which are the necessary connectors and accy circuits needed to complete a setup.
A MicroSquirt is a cased unit with an Ampseal connector, there are 2 versions made a v2(obsolete) and a v3.

Loading the wrong firmware can produce unexpected results.


it has a cased microsquirt firmware loaded btw
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
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Re: flat afr and rpm drop in log file

Postby erlend » Fri Nov 17, 2017 4:17 pm

thank you for clearifying.
I do not have the circut board, but the closed case microsquirt that you connect to with a harness.
On the invoice it was named MicroSqrt8: Assembled ECU (includes 8' harness & tuning cable)
If i remember correctly its V3, i thought i had upgraded the firmware, but might remember this wrongly.
I will try to verify the version of firmware next time im at the workshop.

Regards
Erlend
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Re: flat afr and rpm drop in log file

Postby rickb794 » Fri Nov 17, 2017 4:35 pm

It has 3.4.0 loaded

Your injectors are on the small side, good for 205hp.
Your ReqFuel number is fairly large.
3 bar fuel pressure?

Did autotune make the VE table?
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Re: flat afr and rpm drop in log file

Postby erlend » Sat Nov 18, 2017 1:19 am

Thanks for checking my firmware.

The injectors are stock for this 4.6l engine. The guy selling the engine meant that also swapping over the top with the larger injectors was crucial when I changed out the 3.9l that is original in my rrc to the 4.6l from the p38. It’s the largest version of the “bop”aluminium rover v8 that went in to the range rover. The engine is supposed to have 224h stock.
I was hoping to get a bit more with tuning, but perhaps you’re right and these are maxed out and a bottleneck for tuning above 224h.

I used the interface to calculate required fuel. Is there a better way of finding the right number?

The ve table is copied from Curtis as mentioned earlier.
The default ve table was too rich. I suspect Curtis s table is too lean.
So I need to get the afr reading to work to adjust it. I’ve used the live tune on the table as well, but as the afr might be wrong, I suspect this only made it worse.
I’m tempted to go back to the Curtis table and add a bit of injector time to the whole board.


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Re: flat afr and rpm drop in log file

Postby rickb794 » Sat Nov 18, 2017 9:49 am

My HP calc was at 80% duty cycle so there is some headroom.
So this is a conservative rating. Running the duty cycle up to 95% you are good for 260hp
If you run into trouble you could bump the fuel pressure to give you some more headroom.
Just make sure your fuel pressure does not fall below the rated pressure.

If your VE numbers want to spike up at the top that would be an indication that you are running out of injector.
You will not see it unless you flog it and hit those cells.

ReqFuel number relates to the injector size and is not a problem at this time.

Have you verified fuel pressure? Static? Running? Under full load? Key off Hold?

Have you checked the O2 output in free air (some widebands need free air calibration)?
You need a good wideband to tune and the MS needs to see it accurately for full functionality.
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Re: flat afr and rpm drop in log file

Postby erlend » Thu Nov 30, 2017 2:58 pm

I finally found time to test the car again, and tried to test out some of your comments.

wiring on lc1 has been checked:
red cable gets power from fuel pump rel.
brown cable (analog output 2- wideband 0v=7.35 and 5V=22.39AFR), connected to pink o2 cable on microsquirt (0v)
white and blue cable are joined and then connected directly to neg bat.

black cable (dislay diode light signals while calibrating) - not connected
yellow cable (analogue output 1 - narrowband 1.1v=14afr and .1v=15afr) - not connected

callibration of sensor has been performed
used a new wire from bat + to power the lc1 for calibration (as fuel rel doesnt give power when the car doesnt run)
went through the 20 sec, then 2min in free air, and checked that it was hot.
i also cleaned it with compressed air as it was full of exhaust dust.

it seemed to respond better when the car was fired up, but the attached logfile shows that the curve is still too flat to be beliavable as a actual reading.

Tooth log files has been taken.
i managed to get some longer ones, but mainly short ones. due to this do i not know how to capture the event where the rpm drops.
at low rpm it seems stable. when i increase rpm the tooth log raises, but the car is still running good.
i got some sort of reading from the max rpm test, it goes up to 22. i dont know what this means but its quite alot higher than the low rpm values. the graph at max rpm also seems very unprecise in terms of where the spike is, so there might be a problem here. the error code says 2, which ive read somewhere is missing tooth. at some log files it states that this happened many 20 times, but ive only noticed two missfires at max rpm.
other log files only displays the two errors that i notice. perhaps i also get them if i start logging before i start up the engine?

any suggestions to what type of resistor i can try, and where to place it?

ve table.
Since i dont yet trust the o2 readings, i went back to the unchanged vetable from curtis.
The car runs good when i steadily increase the throthle, but get poor respons at sudden max throthle. i also still get the missfires at 3400rpm.
Im getting a bit worrried that its not healthy for the engine to keep trying to reach the misfires, when i havent made any changes that could get rid of them.
i might try to add fuel to the whole table next time, just to have tried that too.

Fuel pressure.
I havent gotten around to get the right equipment for measuring this yet, but its on my list.

Thanks again for your comments, and any new suggestions you might have.
Attatched are screenshots and files from the tests.

with regards
Erlend
Attachments
MEGALOG.PNG
screenshot megalog
MEGALOG.PNG (143.7 KiB) Viewed 130 times
TOOTH LOG-LOW TO MEDIUM RPM.PNG
screenshot toothlog, low to medium rpm
TOOTH LOG-LOW TO MEDIUM RPM.PNG (90.29 KiB) Viewed 130 times
TOOTH LOG-MAX RPM.PNG
screenshot toothlog, max rpm
TOOTH LOG-MAX RPM.PNG (84.4 KiB) Viewed 130 times
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Re: flat afr and rpm drop in log file

Postby erlend » Thu Nov 30, 2017 3:03 pm

The attatched files.
Attachments
2017-11-29_22.10.39 LAST RUN.msl
msl
(465.98 KiB) Downloaded 2 times
2017-11-29_22.10.58LAST RUN.csv
csv
(398.02 KiB) Downloaded 2 times
2017-11-30_22.47.22.msq
msq
(119.03 KiB) Downloaded 2 times
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Re: flat afr and rpm drop in log file

Postby rickb794 » Thu Nov 30, 2017 3:17 pm

erlend wrote:
Tooth log files has been taken.
i managed to get some longer ones, but mainly short ones. due to this do i not know how to capture the event where the rpm drops.
at low rpm it seems stable. when i increase rpm the tooth log raises, but the car is still running good.
i got some sort of reading from the max rpm test, it goes up to 22. i dont know what this means but its quite alot higher than the low rpm values. the graph at max rpm also seems very unprecise in terms of where the spike is, so there might be a problem here. the error code says 2, which ive read somewhere is missing tooth. at some log files it states that this happened many 20 times, but ive only noticed two missfires at max rpm.
other log files only displays the two errors that i notice. perhaps i also get them if i start logging before i start up the engine?

any suggestions to what type of resistor i can try, and where to place it?



Section 5.2.2 of the MicroSquirt Hardware manual details the use of VR sensors and shows the built in resistor shunts that can be enabled by placing a solder blob across 2 pads on the MS circuit board.
This is my brain on MegaSquirt!
Use only these manuals http://www.msextra.com/manuals/
Avoid the common pitfalls, Read this before start http://www.msextra.com/forums/viewtopic.php?f=101&t=65757
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Re: flat afr and rpm drop in log file

Postby erlend » Fri Dec 01, 2017 4:48 pm

Thanks for the info.
Ive read through the manual, but also tried searching threads to avoid doing the same mistakes as others.
The thread below goes through a lot of trail and error.
It seems likely that the built in shunt resistor might have the wrong value, and that I need to try out different values. Is there a way to try these resistors by connecting them to the cables instead, so I don’t need to open the box?
Any suggestion towards value from my tooth log file?
http://forums.turbobricks.com/showthrea ... 770&page=5.

I’m also curious towards any new tips on my o2 sensor.
After my clean and calibration it looks better in the log, but I still think it seems untrustworthy.
Is there a setup in tuner studio or mega log viewer that I might have gotten wrong?
Or does it look like I should buy a new sensor?

With regards
Erlend



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Re: flat afr and rpm drop in log file

Postby erlend » Fri Dec 01, 2017 4:53 pm

I just saw that the manual illustrates that I should connect the shunt between vr+ and vr-.

I’ll give that a try


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