VW Bus EJ20T

[luisga018]

So guess I need a wideband 02 sensor? I will do as sugested and play by speed density until it is working appropriately. Right know I cant seem to calibrate the IAT and CLT sensors, they read 160F and 180F respectively. I have 1 wire to coolant cable and other to sensor ground and still says 180F. Tried using Saab Bosch settings. Not sure how to fix this.

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What kind/brand of sensors do you have ? What wiring diagram are you using ? Do you have a MAP sensor now that you're not going to run the MAF ?

Also can you answer some of the questions I asked in some of the earlier posts for me and others ?

[luisga018]

Unsure of brand for sensors as they were there when I bought the engine. The MAF has 5 pins as follow:
Send a private message to rao Find all posts by rao Reply With Quote
1. Power
2. Ground
3. MAF Signal
4. Temp Signal
5. Ground
As for the coils is a 4 pack connected to a small ignition module that has 5 cables (1 is power, 2 go to ecu and 2 to ignition) it starts great but fails to stay on. I assume since it doesn't know it's cold it's not putting out right amount of fuel. Should K switch to GM style sensors for IAT and CLT?

I have not used test mode for spark or ignition.

I am using http://www.microsquirt.info/uswiring.htm for diagram reference.

TPS sensor reads ok, spark seems to be working appro since engine starts and idles for about 20 seconds then dies, crank sensor seems to be outputting correctly. MAF seems to have voltage and is reading something ( haven't gone into seeing if readings are correct yet).

Only thing I am currently having issues are CLT IAT and O2 and if it needs changing to Wideband to fix it I will do it happily.

Sorry for the confusion and the noobiness.

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Like rickb794 said......loose the MAF and get a MAP sensor that Microsquirt recognises and it would be good if you could go with the GM sensors as I think it's easier. You can use your Subaru ones and do this......https://www.diyautotune.com/support/tec ... s-iat-clt/. I've only ever used the GM ones.......eliminates any extra stuff to go wrong etc.

For the wideband I'd go with a Spartan from 14point7 or a PLX.

No worries on the noobie questions.......I'm in the same boat.

[rickb794]

Try other settings until you get a sane reading.
Or you may not be connected to a ECU temp sender
You should not try to use a gauge sender for a ECU temp sender.
Your motor may have both types of sensors installed.
Check for other temp sensors, engine control sensors usually have 2 wires.
Near the thermostat or hot coolant outlet some place that gets coolant flow even when the thermostat is closed.
Some sensor may have both gauge and controls in one sensor, use an ohm meter to check value and path.
Some may ground to the motor and some may have a signal return.

GM sensors will not fit the metric threads in your Subie motor.
They are not necessarily any easier to make work.
Note the MS will default to 180° if it thinks there is a fault on the CLT (an open connection or short).

The Subie used a IAT in the airflow meter if that is still in the air stream you can use that.
You want an exposed element temp sensor for the IAT for quick response.
A motor mounted IAT can sometimes be influenced by engine heat so mounting it remotely is advantageous.
Near the cold side of an intercooler is a good spot, you are running a cooler, yes?

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rickb794.....just curious re the Subaru IAT in the airflow meter......that would be before the intercooler......is this ok to run like that ? So is it part of the MAF then ?

The Subie used a IAT in the airflow meter if that is still in the air stream you can use that.
You want an exposed element temp sensor for the IAT for quick response.
A motor mounted IAT can sometimes be influenced by engine heat so mounting it remotely is advantageous.
Near the cold side of an intercooler is a good spot, you are running a cooler, yes?

[rickb794]

Excellent point! No, I think you want the IAT to reflect the temp of the air being introduced into the motor.

This brings to light another aspect of using a MAF,
If using a Blow off valve or boost dump valve it will need to exhaust air back into the system after the MAF
So the MAF signal represents the air being consumed, boost that is dumped would need to be recirculated rather than just expelled.
Otherwise the MAF reading will be high and the motor will be overfueled.

[luisga018]

Hello,
I bought a GM Sensor at Pepboys to test out and still sees it as 180. I created a short cable to test out of the engine and still see 180F. Could the shortcircuit be elsewhere and affecting CLT? Unsure what to check.


Troubleshooting says the following:
If your CLT (coolant) temperature sensor doesn't respond, you can:
disconnect the DB37 at MegaSquirt, and check the resistance from harness pin 21 to ground pin 7 (i.e., the coolant sensor reading), if it is between 100000 and 200 Ohms, you should get a temp reading. If it is ~zero, your wiring is still shorted.
the stim is the easiest way to check the MegaSquirt, but if you don't have one, you can check the components in the CLT circuit (which you would have to do if a stim showed it wasn't working in any case...). These are:
R7 - this is the resistor through which voltage is applied to the sensor, so check it very carefully to make sure it is the right value, well soldered, and not bridged to other nearby components.
R8 - this is the resistor that 'protects' the CPU pin - if it isn't soldered properly, no signal will get through it to the CPU, so check it very carefully to make sure it is the right value, well soldered, and not bridged to other nearby components.
C6 (V3 board) (C7 on a V2.2 board) - this will only cause you problem if it is shorted. If you pass the above tests, you can try measuring the resistance, but a better bet is to pull up one leg of the capacitor, and see if the CLT works.
C7 (V3 board) (C8 on a V2.2 board) - this will only cause you problem if it is shorted. If you pass the above tests, you can try measuring the resistance, but a better bet is to pull up one leg of the capacitor, and see if the CLT works.
Other things that can cause problems are the soldering of the CPU socket, the MS-II not seated properly, or corrupt code (you might try reloading the code to eliminate this slim possibility).

My microsquirt came pre-built I have no clue what to check for!

WT3000P Temperature Sensor sensor I bought

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You're running a Microsquirt right? Where have you threaded it into? Or are you just going off of ambient temps just test purposes ?

[rickb794]

With a MicroSquirt unless you are prepared to do SMT board work, all you can do is check the externals.

Substitue a resistor of the correct value from the CTL lead to ground if the MS does not respond correctly it is likely an internal problem.
Verify your Vref is not getting messed with.
Check also that the correct firmware is loaded and the calibration has been set accordingly.
Reload firmware if in doubt.

Then Contact your reseller to see what your options are?

[luisga018]

You're running a Microsquirt right? Where have you threaded it into? Or are you just going off of ambient temps just test purposes ?

I am running off ambient and tried a bowl of hot water. Still 180. There are only 2 cables for sensor, so I created a new small cable just for this to the bowl and nothing. That's what puzzles me as there is not suppose to be a short. Will check tomorrow if something is messing the Vref.

[rickb794]

Back probe the Ampseal connector CLT pin with the coolant sensor disconnected and see if there is a lower than Vref potential present.
No voltage present would indicate a short on that circuit or an internal issue with the MS.
A resistor to ground at that point should also change the MS reading for CLT.

[luisga018]

Hello guys,
I changed the sensor to another one for "GM" and this one worked and it's reading almost correctly (it's off by about 5 degrees) but that's easier to calibrate. Thanks for not losing hope on me! I bought a MAP sensor but unsure how to know what it's default value with engine off and how to test it.

Also... where should I hook it up? Thought maybe I could use one of the lines from the fuel pressure regulator since it uses vacuum.

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Also... where should I hook it up? Thought maybe I could use one of the lines from the fuel pressure regulator since it uses vacuum.

As for the wiring......I just Googled.......microsquirt map sensor wiring. Should be in the manual though .

What p/n or brand etc is the MAP sensor? As for the vacuum source I bet there is a spare vacuum port below the throttle plate on the manifold that you can use.