1990 325 5sp stock

[DevInAz]

Goal: better running 325 than stock with future turbo upgrade in the next year. This is a daily driver.

specs: stock m20b25
          Bilstien sport shocks with H&R lowering springs
          New brembo rotors with new pads and steel brake lines all around
          z4 short shifter
          New motor mounts/trans mounts and cooling system minus radiator
          custom injection wiring - stock ignition with all new components
          3.6 VEMS
          board mounted MAP
          EGT
          PS2 - I made an error ordering the ps2 and didn't want it but i'll leave it since its there.

Tuning: Mattias - M20  config thats been adjusted for our injections and local 91 fuel




air flow meter delete with factory air box. we used a m30 afm flange and bolted it to the stock box and modified it to fit. the aluminum tube still needs to be welded but thats the basic look of it.























The wiring still needs to be cleaned up but first I need to get the wideband working correctly. The car runs really good but for some reason the wideband is reading .06 o2% while trying to calibrate. I've doubled and triple checked my wiring and my supply voltage and grounds. All the wideband settings are default expect the two setting I recieved with my build sheet. Those are entered correctly. i've switched out my o2 sensors with known good ones also. As a side note while trying to calibrate my o2 sensor it says heating and never changes. i don't know if this is a hardware or software issue. I've submitted a error report here: http://vems.hu/vemstune/bugreports/reports.php?cmd=view&key=bgjoII

[DevInAz]

still working on the wideband problem here:   http://www.vemssupport.com/forum/index.php/topic,1905.0.html

The cars EGT will get ran tomorrow.

[DevInAz]

UPDATE:

The car is running great after I was sent another VEMS to fix my wideband problem.

I would like to hook up the MPG gauge just to see it move around. I don't care if its accurate or not. Has anyone ever got this to work some what with a P or S output? I hooked it up to a stepper but it would stay maxed out. I need to figure out the resistance range of this gauge.

[Erikk]

Check out mattias memberspage: ../MattiasSandgren/BmwEconoMeter

[DevInAz]

It appears this can't be done without some serious effort. Are the designers still planning on installing a variable output table for something like this?

[DevInAz]

I need a 12v source to power up the switching side of a relay. Could I do this with a diode and a stepper driver to do this?

The relay I need to turn on is a switch power and it would be to much work to swap this around in the fuse box.

[gunni]

Sure, although bmw never wires it up that way,.

[DevInAz]

This car seems to have developed a problem in the heat.  Once the car is warmed up and the air intake sensor starts to read above 70C the vehicle goes extremely rich.  I've adjusted the MAT/TPS table to remove all the fuel down to 68 in that table and it helps but it doesn't fix the problem.  I'm thinking this is a VEMS hardware issue which i'll verify with another VEMS I have here. Has anyone else seen this problem?

I'll post up some pictures of logs showing the problem.   Normal idle for this car is 1 lambda.  During the problem the vehicles lambda drops down to .7 and maxs out the wideband sensor.   While running open loop with the sensor disconnected it does the same thing.

Ideas?

Logs can be downloaded from here:    http://vems.hu/vemstune/sharingcenter/reports.php?cmd=view&key=S1U1mh#comments

the log thats 30kb is the log that shows the problem.  The MAT/TPS table shows a higher reading than it really was set at. I was moving these numbers around.

[stroft]

Heatsoak Where is your MAT sensor located ? Is this some kind of OEM BMW sensor or the one from VEMS Shop ?

[gunni]

I´m not seeing any lambda values in the 30kb log.

Do you have a means of measuring the pipe the sensor is fitted to(like infrared little gun thing)? Is it the stock closed one that is extremely slow to react?

[DevInAz]

Its located in the air filter box. Its a stock BMW temp sensor.   Even if its heat soak I should be able to compensate for the temps with the MAT/TPS sensor shouldn't I?

I´m not seeing any lambda values in the 30kb log.

Do you have a means of measuring the pipe the sensor is fitted to(like infrared little gun thing)? Is it the stock closed one that is extremely slow to react?

Gunni it is reading as no reading because the car is running that rich. Its pig rich and maxs out the sensor o2 sensor. The intake air sensor is the open element that the webshop sells, and its screwed in to the side of the air box like a e34 m5 has it.  I do have a IR temp gauge I can double check everything with.

[GintsK]

Where is file with problem?
Your MAT/TPS table is flat. And this means richer mixture at higher temperatures.

Gints

[DevInAz]

Hey Gints

Your right the table is flat but that isn't enought to make a car run at 1 lambda at one moment and .7 lambda the next.

I uploaded two more logs. The latest is how the car is setup right now and the one above is the first log I got showing this problem. The bigger problem is the rains have moved in and dropped out outside temps down to 80F from 105F. The weather says it won't warm up again this year so this problem might not show itself till next summer.  I'll update if the problem comes back before then.  In the mean time since I have a feeling this is a VEMS issue not a tune issue i've installed another VEMS to test just in case the problem comes back.

[GintsK]

Now I see. Your MAP sensor is calibrated wrong! It is not possible to reach 0Kpa. But your log contains 0kpa few times!

I guess it is 300KPa sensor not 400. (?)

Gints

[DevInAz]

Now I see. Your MAP sensor is calibrated wrong! It is not possible to reach 0Kpa. But your log contains 0kpa few times!

I guess it is 300KPa sensor not 400. (?)

Gints

Gints you are correct! my purchase order from VEMS says they installed a 400kpa sensor. So thats what I put in my config but I should have caught that problem.

I have driven the car and retuned the VE table. It still needs some more work but its running much better. With the new VE table settings my MAT/RPM table seems to have much more impact with its adjustments than before. 

Since this car is N/A and the customer has decided to keep it this way the map sensor change doesn't matter.

thanks again!