How to interpret scan results - any reference material?
Thread Starter
Pro
Joined: Dec 2000
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From: RDU NC
How to interpret scan results - any reference material?
So I just did my first series of scans on my 85. Used WinALDL first then used TunerPro RT second. Is there a resource anywhere that can help me interpret what I'm seeing? How am I supposed to know what the acceptable values are, and what it means when the values are outside (up or down) the range?
So far I think it is running quite rich (suspected this for a while now) based on the BLM value of 108.
Thanks for any info/references!
So far I think it is running quite rich (suspected this for a while now) based on the BLM value of 108.
Thanks for any info/references!
Le Mans Master
Joined: Aug 2007
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From: WV
The FSM should have specs in it for what the readings should be. I got a book with my Auto-xray scanner that tells what each reading should be and what is high and low readings. There has to be a book on the market for scanning and tuning that has this info in it.Maybe someone on here knows of such a book...WW
Race Director
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From: Merritt Ils Fl
Burning Brakes
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Cruise-In II Veteran
The most common book referred to is:
"How to Repair and Modify Chevrolet Fuel Injection" by Ben Watson published by Motorbooks International. ISBN 0-87938-052 Retailed for $19.00 in 1991.
Like WW7 mentioned most of the "proper readings" are in the service manual.
Post your scan in the C-4 Scan and Tune section. There are some sharp people there that probably would be happy to interpret it for you.
"How to Repair and Modify Chevrolet Fuel Injection" by Ben Watson published by Motorbooks International. ISBN 0-87938-052 Retailed for $19.00 in 1991.
Like WW7 mentioned most of the "proper readings" are in the service manual.
Post your scan in the C-4 Scan and Tune section. There are some sharp people there that probably would be happy to interpret it for you.
Last edited by Wildride; Jan 11, 2011 at 08:12 PM.
Thread Starter
Pro
Joined: Dec 2000
Posts: 555
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From: RDU NC
The most common book referred to is:
"How to Repair and Modify Chevrolet Fuel Injection" by Ben Watson published by Motorbooks International. ISBN 0-87938-052 Retailed for $19.00 in 1991.
Like WW7 mentioned most of the "proper readings" are in the service manual.
Post your scan in the C-4 Scan and Tune section. There are some sharp people there that probably would be happy to interpret it for you.
"How to Repair and Modify Chevrolet Fuel Injection" by Ben Watson published by Motorbooks International. ISBN 0-87938-052 Retailed for $19.00 in 1991.
Like WW7 mentioned most of the "proper readings" are in the service manual.
Post your scan in the C-4 Scan and Tune section. There are some sharp people there that probably would be happy to interpret it for you.
I did a quick glance through my FSM but couldn't find any specific values- just a bunch of test-light results. What section should I be looking in do ya think?
I may try to do that once I get a good driving scan instead of just idling in the garage.
Thanks for the reply!
Race Director
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From: Database Error Indiana
Important #s to look at are BLM and Int. They should be 128 + or - 8.
IAC should be around 30 at idle.
TPS around .5 at idle.
O2 should be constantly switching up and down with 450 the middle.
Knock counts at 0.
IAC should be around 30 at idle.
TPS around .5 at idle.
O2 should be constantly switching up and down with 450 the middle.
Knock counts at 0.
Safety Car
Joined: Jan 2004
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One thing I think would be good to know is what your timing at idle should be on your scans. I think there are two different timing numbers you get though. That way you can make sure your balancer hasn't slipped causing you to set the wrong timing.
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Le Mans Master
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From: WV
I've read it is normal to get knock counts on start up.
One thing I think would be good to know is what your timing at idle should be on your scans. I think there are two different timing numbers you get though. That way you can make sure your balancer hasn't slipped causing you to set the wrong timing.
One thing I think would be good to know is what your timing at idle should be on your scans. I think there are two different timing numbers you get though. That way you can make sure your balancer hasn't slipped causing you to set the wrong timing.
Last edited by WW7; Jan 12, 2011 at 10:21 AM.
Thread Starter
Pro
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From: RDU NC
Here's what I got, even though I don't consider this a good scan like I want by starting the scan with a cold start. The car was mostly warm and idling when I started the scan. Interesting nonetheless:
Closed loop the whole time.
O2 was all over the place between 100 and 850
TPS voltage was constant at .53 (I can't adjust it any further to achieve .54- could be bad maybe)
The First 8 minutes:
BLM:108
INT: 104-108
Coolant Temp (F): 140
MAT (F): started around 145 ended around 170
IAC: around 90
The last 30-40 seconds of logging read:
BLM and INT: 128
Coolant temp F: 97
MAT (F): 170
IAC: 144
Closed loop the whole time.
O2 was all over the place between 100 and 850
TPS voltage was constant at .53 (I can't adjust it any further to achieve .54- could be bad maybe)
The First 8 minutes:
BLM:108
INT: 104-108
Coolant Temp (F): 140
MAT (F): started around 145 ended around 170
IAC: around 90
The last 30-40 seconds of logging read:
BLM and INT: 128
Coolant temp F: 97
MAT (F): 170
IAC: 144
Last edited by c4_4ya; Jan 12, 2011 at 11:06 AM.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
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From: WV
If you go to the site below and go to page 63 this is the start of all the readings for the OBD 1, This will tell you what each reading means.This is a large file and may take a minite to load but you can save it to your document folder and then use it when ever you want This should help you out...
...WW
http://www.autoxray.com/publish/2007...english_71.pdf
...WWhttp://www.autoxray.com/publish/2007...english_71.pdf
Last edited by WW7; Jan 12, 2011 at 11:21 AM.
Safety Car
Joined: Jan 2004
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One problem I've had with my scans with a Tunerpro RT. Is that it likes to all of a sudden stop reading data. Which causes you to have to restart the car and start the scan over again. I've read it has to do with the computers used in the late 80's Vettes that causes this problem.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
One problem I've had with my scans with a Tunerpro RT. Is that it likes to all of a sudden stop reading data. Which causes you to have to restart the car and start the scan over again. I've read it has to do with the computers used in the late 80's Vettes that causes this problem.
Safety Car
Joined: Jan 2004
Posts: 3,759
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Josh, another thing that can cause your program to stop running is if you have a screen saver or a sleep mode on your laptop that comes on while your running a scan. As soon as these come on they stop your program cold, you have to remove or shut off these items before you do a scan...WW
Over at Tunerpro, they say the problem is the particular computer that is in the car on the late 80's Vettes and any other car that uses that same computer.
