Megasquirt help needed...

[Hybrid_From_Hell]

Hi Hendrik,

Have had a study of the log and have run the tunning software, however some info below

On the key Perameters some good news

MAP 16-100

RPM 0-4929

TP 9-97

Spark 0 - 36

O2 0 - .922

Some better news - your CTS and MAT are now working.....

And some not so good news :

Although the sensors for CTS And MAT are working the rnages still look wrong......

CTS - 106-121 - THAT VERY HIGH, I would have expected say on a warm engine 83 and a hot enhine aeround 100

MAT 50-87, again the air temp seem Higher than I would have expected.

I think you may still have an issue with the Sensor calibrations, this needs prob fridge or Ian G to resolve, but they will wnat to know :

The make and model / part number of both sensors, and what S19 file / calibartion settings you have,

I think now you have sensors that are working, but reading wrong, and thats why I haven't sent back the Revised MSQ File cos it wnats to richen things up HUGELY in the low rnage which I think is wrong - and hence why I query the sensors.

Secondly I note 0 rpm for a large chunk opf the 1st part of the log, this obvioulsy means the Engine not running,

but then when it does run its a good 3rd way into the log before the O2 sensor kicks in, as such I would ask you..........

1 - When the engine was started was it already good and warm ? and how warm or was it cooled down ?

2 - I would suggest that when you datalog you need the ngine FULLY warmed up, this way the O2 sensor will record from start up

3 - have the engine running and warmed up THEN on Megatune click File Datalogging etc. and with the engine running....

4 - If.... as I am wondering..... the engine maybe wasn't fully warmed up .......then that again queries the start CTS setting reading of 106, thats HOT

5 - where have you mounted the MAT sensor ?

Can you also re e-mail me (or try) the full MSQ File, ...............just wnat to see that I am using the right one to tune

Nige

[Bull Bar Cowboy]

OK ……………… looking at the xls file, I see a problem……………..

The log starts with the coolant sensor (CLT) at 117 (assumed to degrees C) and the air temp (MAT) at 86 ( assumed to be degree C)…………so either the ECU is reading those values incorrectly, or you had already warmed the engine.

But …………. It gets worse that that……………..

Lines 3 – 638 show the engine as stationary (engine =0) , however the CLT and MAT are as above……

Lines 639 - 641 show you are cranking the engine ready to start (engine = 1)

Lines 642 – 655 show the engine as cranking AND running (engine = 3 )

Lines 656 – 872 show the engine as running, with start up enrichment and warm up enrichment (engine = 13) ………… this is probably true as the default for startup enrichment is 11 seconds and the log timing counter shows it active for 11.108 seconds (89.004 – 77.896)

However…………. this is where the problem is evident …………..

The rest of the log lines 873 - 1108 (end of log) show that the engine never comes out of 'warm up' enrichment (engine = 9) …………. The ‘engine’ field log entires show the following,

9 = warm up enrichment

25 = warm up enrichment and TPS enrichment (i.e. you blipped the throttle )

41 = Warm up enrichment and TPS deceleration enrichment (i.e this occurs at the instant you release the throttle)

So to sum it up ……………… your CLT sensor is telling MS that the engine temp is at its lowest 106 and a max of 121 …………. but the MS is still in warm up mode ……..

My guess is that you have set Megtune and the MS firmware to degrees F ……………. As 106F = 41C and 121F = 49C ……………. This would explain why warm-up enrichment is still ‘on’ as this does not drop out until 71C………………

The total log time is 728 seconds (12.1 minutes) .............. so if you started from a cold engine and the CLT & MAT are reading Degrees F, then the above is probably OK ................... we need to see a log file with the engine AT operating temperature.................

Also I am seeing a problem with the O2 sensor ………………. It is not showing any activity for the first 197 seconds (3.2minutes) of the log run ……………I would expect to see a returned voltage after a 30 second heater warm-up ………… also there are periods in the log where the sensor seems correct, and other periods that show no activity………….

However, one thing at a time …………… you need to sort out the coolant and air temp sensors first as the O2 sensor is ignored until the coolant temp is above 71C (default)

Ian

[Ced]

However, one thing at a time …………… you need to sort out the coolant and air temp sensors first as the O2 sensor is ignored until the coolant temp is above 71C (default)

That can be done quite easely, they are just dagling around in the engine bay

[FridgeFreezer]

That can be done quite easely, they are just dagling around in the engine bay

[Hybrid_From_Hell]

That can be done quite easely, they are just dagling around in the engine bay

If you've finished with it now John can I borrow it for an hour or two please ?, then I think Ian may want a go with it

Nige

[Hendrik]

OK so the truck is more or less finished, no dagling sensors or anything else, we had some small tests on and offroad, which were great! but what we found out is that, how do i say it in english, the iddle is to "high". it is around 2000 2500 rev's per minute.

I did some research and it should be around 800-1000 rpm. What is the best way to reach this low level? any tips?

Thanks in advance!

Hendrik

[Hybrid_From_Hell]

no dagling sensors or anything else

Yippe do.......are you sure there no other "Joys" to mention ?

Re the issue you mention :

MS Does not control the idle speed

that is controlled by the allen head bolt in the plenum chamber near where the hose joins, remove the balnking plug if it is still there and wind up / down to reduce the idle. This assumes that :

1. the throttle cable isn't adjusted too tight / wrong / causing the high tickover

2. The butterfly in the plenum hole has been set properly /áccurately

3. That you ahve equally done the calibration on the TPS low and high points as this I think is interlinked although affecting MS won't cuase it to happen, but if you adjust 1 or 2 then 3 will then need redoing

Nige

[FridgeFreezer]

As Nige says, it's probably the idle speed screw now you don't have a restrictive AFM in the way. Check for unplugged ports or holes on the plenum such as the vacuum feed for the dizzy, fuel pressure regulator.

You don't need to calibrate the TPS, MS only measures the rate of change, not the actual voltage.

[Hybrid_From_Hell]

Unless of course the TPS is also dangling in the engine bay

[TomG]

You don't need to calibrate the TPS, MS only measures the rate of change, not the actual voltage.

This is true as the fuelling / spark is MAP driven (unless running Alpha-N), the only exception is if you have acceleration enrichment TPS-based it would help to have it properly calibrated so it kicks in immediately.

Also when logging, if TPS is correctly calibrated, i think MegaLogViewer will interpret no throttle as zero percent.

Call me fussy but TPS calibration is a 5 second job and dead easy to do in Megatune.

Either way it won't have an effect on idle speed.

[Hybrid_From_Hell]

Calibrating would also show if you don't have the 'full rang'e of movement.

(Not applicable if dangling in engine bay of course )

Nige