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Temp signal issue


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Youve got some interesting electrical issues going on there. Way more than just the temp sensors.

You battery voltage comes and goes. between 1:10 and 1:14 it drops to 0 half a dozen times, usually right when your temp sensors go into their minimum value of -40C. there is also a quite worrying spike up to 40.9V battery voltage when it comes back, and when this happens your sensor all add about 50degC to their readings so that voltage spike is clearly reaching the sensors. I'm guessing it arced a bit when reconnecting to voltage.  I suspect your temp sensor variances are directly related to loose wiring, probably near something major given how many of the systems it hits an once - eg the ground on the engine block or the battery, or somewhere between your battery and the main fuse box. Its also possible you have some exposed wiring somewhere un-fused (like the wiring to the starter motor) and its contacting something and causing an intermittent short.

Your lambda sensor drops in an out, and sometimes when its working its giving you insane values eg at 1:16 you apparently were at full throttle when your lambda went from 0.8's to a value of 8.something! (not afr, lambda...). On second look some of the dropouts are caused by voltage drops and it going through the startup process again, but the spikes up to very lean numbers while at full throttle dont make sense.

At 1:07 it looks like your injectors cut out or something. You're still at full throttle but it goes crazy lean and your MAP + revs start to drop.

are while not a wiring issue, you fuel table values are maxing out at 150 for large parts of the full throttle run. If this is on modelled, you need to check your injector flow rate config, that the configured fuel pressure matches the pressure set on the regulator, and that the correct engine capacity is configured. If its traditional, you probably need to double your master fuel number, and halve all the values in the fuel table (select the whole table and type " / 2 <enter>"

Also, you very lumpy idle is probably related to your fuel table numbers near idle being so different. it moves from ~50 to ~90 between 1000 and 1500rpm and only moving about 20kpa.

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Thanks for the reply! I think the problem has to do with EMI as it happens at high load in 4th gear.  I managed to reproduce the issue and made some more logs (See attached) with different boost levels, the higher the MAP the earlier in the engine speed this problem occurs. At 3 bar boost (MAP reads upto 2.5) EMI apears at 5000rpm, at 1.8 bar boost EMI appears at 7200rpm....

Anyone had EMI issue before? I suspect the M&W CDI ignition sstem could be causing this? I am attaching a photo of the engine where coils can be seen, can their location cause this issue?

All ECU grounds as well as ground for M&W coils are connected to the engine head,  the engine is properly connected/earthed to the chassis. Battery is in te back properly connected to the chassis.  The reason wh we switched to LINK ECU is because we were having issues with EMI interference and were hoping that LINK will be the cure :(

Thanks for the comments related to idle and injectors, this will be fixed with more breakpoints and injectors will be scaled to allow lower numbers in te VE map, I have Siemens 2200lbs injectors in a 2 litre engine so had to temporaril trim settings to make them work at idle. 

Please help :(

emi 2.1 barboost.llg

EMI 2.2bar boost.llg

emi 1.8 bar boost.llg


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10 hours ago, Turbohead said:

Battery is in te back properly connected to the chassis. 

Hmm, that sounds like a potential problem.  The high tension voltage will have to travel all the way through the chassis to find its way back to the battery.  To minimise interferance the general idea with grounding is to make the magnetic loop area as small as possible, in this case you have basically turned the whole chassis into a big magnetic loop. 

Can you try a proper ground cable from the battery -ve post direct to the engine block or gearbox case, or even try a heavy jumper lead as a temporary test.

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How have you done the wiring between the CDI and the coils? Have you followed the M&W manual?

I'm running M&W CDI with denso coil on plug and have no issues with the battery being at the back of the car. Just earthing battery to body but I guess not all boddies are the same.

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Thanks Adam, I will try that. 

Ducie54 thanks for the reply, i bought the wiring loom together with the M&W cdi package from T1racedevelopments, the loom looks to be proffesional and is made as described in M&W instructions with twisted wires etc. I had extensive email exchange with M&W and tried ll their tests. 

One thing i have noticed with the previous ecu when i used HT leads and spark plugs with resistance i had a better situation however at high boost high rpm the problem was still present.

When i would used no resistance HT cables and spark plugs the issue would apear as soon as engine speed would reach 1800rpm!

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