VW Beetle Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter · #1 ·
I just replaced the MAF sensor and after getting a UScan reader that can see the voltages I was wondering if anyone knew what the reading should be? it reads about .36 at idle with the coolant at 154 degrees in Park. when I rev it up to about 2500 the voltage looks like about 1.3V or so. didn't run it too long and it looks like the sample rate on the reader is kinda slow. I am using a Bluetooth reader that connects to my phone. thanks for any help
 

·
Registered
Joined
·
2,545 Posts
154

whoa wait I believe your coolant temp. is way off dude it should be around 200 Degrees F. even at Idle.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #4 ·
it had only run for about 5 minutes. the blue temp light had just gone out but I will watch the temp. thanks
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #5 ·
thanks, I checked the volts while revving it up and it was pretty even going up and down. the graph didn't show any wild spikes. this was after replacing the MAF so that probably fixed the check engine light. still smell like its running rich though
 

·
Registered
Joined
·
15,839 Posts
Any trouble codes; please scan the car with a vw compatible scan tool. A bad coolant sensor; will throw a trouble code. A bad temp sensor; will cause a hard start, rough idle and rich condition. Once, the car warms up; the symptoms can go away, rich will still be there and your gas milage, will suffer.

What are you fuel trim levels?

Fuel Trim Info - Ross-Tech Wiki
 

·
Registered
Joined
·
3,690 Posts
A generic OBDII tool is more than adequate for drivability issues.

Sorry to say I stay FAR away from ANY Actron tool, they are WAY overprice and pretty useless as far as I am concerned.

Weak/soft thermostats are pretty NORMAL for these cars.

These engines should read the point to turn off the Blue coolant light in 1 to 1.5 miles or about 3-4 minutes of driving. Nominal engine coolant temp should be around 205F.

Read these links:

http://newbeetle.org/forums/question...e-options.html

http://newbeetle.org/forums/1-8-lite...mp-sensor.html

Get an OBDII smart phone/tablet App and interface, typically $30 or less. These Apps support Emission Readiness Monitor Status, Freeze Frame and Live/Realtime data. They are also great for Logging data for review after the car has been driven and can really help find usual problems.

Android - Touch Scan for $3.95 and ELM327 OBDII to Bluetooth interface.

iProduct - OBD Fusion for $9.95 and ELM327 OBDII to Wifi interface.

If you want to get something VW specific, this is fine, but for now you really do not need it. You need something FAR better than the UScan.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #8 ·
Any trouble codes; please scan the car with a vw compatible scan tool. A bad coolant sensor; will throw a trouble code. A bad temp sensor; will cause a hard start, rough idle and rich condition. Once, the car warms up; the symptoms can go away, rich will still be there and your gas milage, will suffer.

What are you fuel trim levels?

Fuel Trim Info - Ross-Tech Wiki
well I am using a UScan device that talks to the phone through Bluetooth. Advance had them on sale at 1/2 price. the temp gets up to 199-208 and stays there while driving according to the recording. every time I try to send the log to my email it just send the first page and first capture.

it gives 2 readings I think are fuel trim: ST FTRM1 and LT FTRM1. ST FTRM at idle varies from -2.3 to 0.8 with an RPM of 698-713. LT STRM stays at -0.8 regardless of RPM. at 50 MPH STFTRM is at 7.0.

if I figure out how to upload the graphs i'll do that. let me know if this means anything.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #9 ·
A generic OBDII tool is more than adequate for drivability issues.

Sorry to say I stay FAR away from ANY Actron tool, they are WAY overprice and pretty useless as far as I am concerned.

Weak/soft thermostats are pretty NORMAL for these cars.

These engines should read the point to turn off the Blue coolant light in 1 to 1.5 miles or about 3-4 minutes of driving. Nominal engine coolant temp should be around 205F.

Read these links:

http://newbeetle.org/forums/question...e-options.html

http://newbeetle.org/forums/1-8-lite...mp-sensor.html

Get an OBDII smart phone/tablet App and interface, typically $30 or less. These Apps support Emission Readiness Monitor Status, Freeze Frame and Live/Realtime data. They are also great for Logging data for review after the car has been driven and can really help find usual problems.

Android - Touch Scan for $3.95 and ELM327 OBDII to Bluetooth interface.

iProduct - OBD Fusion for $9.95 and ELM327 OBDII to Wifi interface.

If you want to get something VW specific, this is fine, but for now you really do not need it. You need something FAR better than the UScan.
Ok so USCAN does not give enough info I guess. I think its because the scan rate is really slow, like 5 - 10 seconds. a lot happens in the time between frames. it does give readings for VW, with a download. see my other post above.
 

·
Registered
Joined
·
3,690 Posts
Spent the $30 or less for the Apps and interface I suggested.

Actron is SO much crap I cannot even believe they sell these things, but the ONLY reason they are in business is they have parts stores with these hanging on the pegs.

Do not worry about the MAF Voltage, you want the MAF reading in Grams/Sec.

What is the LTFT while cruising at 50 MPH.

Put your original MAF back on the car, P0170 is RARELY a MAF problem.

You could try to see if the UScan device will work with TouchScan.

TouchScan offers a 2 week fully functional trial.

https://www.obdsoftware.net/software/touchscan/trial
 
1 - 10 of 10 Posts
Top