scan look ok?
Melting Slicks
Joined: Apr 2003
Posts: 3,110
Likes: 6
From: Red Sox Nation! RI
I can't be of any help with your scan data, but have you checked the obvious tune up stuff? I just cured a similar flat spot in the same rpm range with a cap, rotor & wires.
And if you want to drive 10 mins south, you can come scan my car!
And if you want to drive 10 mins south, you can come scan my car!
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Need to know abit more info here, like what that DTC code is youre getting, and why you have not set the vehicle type in the options. What mods (if any) do you have?
According to your STerm youre rich, yet the O2s are reading lean. (seems more so on the right bank, and this could be nothing major since the LTerm is saying lean) Really need to know the answers to the above!!!
According to your STerm youre rich, yet the O2s are reading lean. (seems more so on the right bank, and this could be nothing major since the LTerm is saying lean) Really need to know the answers to the above!!!
Last edited by Casethecorvetteman; Jun 22, 2006 at 09:29 AM.
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
That DTC code popped on showing "service ASR" upon plugging the cable into the computer. After I unplugged, it went away.
I will scan again with the correct vehicle type.
mods include lt4 hotcam, SW full length headers, high flow cats, 3" B&B exhaust. PCM chip and an electric waterpump.
Also have new plugs, MSD wires, MSD coil, new optispark and MSD 6al
I will scan again with the correct vehicle type.
mods include lt4 hotcam, SW full length headers, high flow cats, 3" B&B exhaust. PCM chip and an electric waterpump.
Also have new plugs, MSD wires, MSD coil, new optispark and MSD 6al
Safety Car
Joined: Sep 2003
Posts: 3,599
Likes: 24
From: Orange County NY
St. Jude Donor '10-'11-'12-'13
To really diagnose, we would need to see the data log over a period of time, specifically when the problem is occuring.
I see the knock count field has registered 1108 counts, which means the sensor is picking up knock (either false or real) at some point(s). This could be happening during acceleration (around the 1800-2200 rpm range you noted), causing the ECM to pull timing. That could be giving you the "misfire" feeling you are experiencing.
At this particular point in time (snapshot), the O2 voltage is very low. If this is happening when you hit the throttle, you could be experiencing a momentary lean condition, which will cause the engine to stumble and possibly backfire. The acceleration enrichment or "pump shot" would need to be increased via re-programming the chip to add more fuel when hitting the throttle.
I see the knock count field has registered 1108 counts, which means the sensor is picking up knock (either false or real) at some point(s). This could be happening during acceleration (around the 1800-2200 rpm range you noted), causing the ECM to pull timing. That could be giving you the "misfire" feeling you are experiencing.
At this particular point in time (snapshot), the O2 voltage is very low. If this is happening when you hit the throttle, you could be experiencing a momentary lean condition, which will cause the engine to stumble and possibly backfire. The acceleration enrichment or "pump shot" would need to be increased via re-programming the chip to add more fuel when hitting the throttle.
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
Oh no that $%#@! did not throw code 16 on me. Just checked HELMS and its a problem with the opti not throwing a low-res pulse. That opti is brand new and has less than 200 miles on it.
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Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by sonomacrew01
Oh no that $%#@! did not throw code 16 on me. Just checked HELMS and its a problem with the opti not throwing a low-res pulse. That opti is brand new and has less than 200 miles on it.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
Originally Posted by sonomacrew01
Oh no that $%#@! did not throw code 16 on me. Just checked HELMS and its a problem with the opti not throwing a low-res pulse. That opti is brand new and has less than 200 miles on it.
If it does turn out to be the opti, I seen where one of the venders is having a group purchase on the msd opti. I believe it was $429.00
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
here's what the helm says for troubleshooting DTC16
1) Clear DTC's, crank engine 15 seconds, does DTC set?
done it and yes DTC still sets code 16
2) Ignition off, disconnect ignition system test connector, ignition on,measure voltage on terminal A at the ecm side of the ignition test connector.
First off, wheres the ignition test connector and wheres terminal A
1) Clear DTC's, crank engine 15 seconds, does DTC set?
done it and yes DTC still sets code 16
2) Ignition off, disconnect ignition system test connector, ignition on,measure voltage on terminal A at the ecm side of the ignition test connector.
First off, wheres the ignition test connector and wheres terminal A
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,107
Likes: 0
From: RI
1) Clear DTC's, crank engine 15 seconds, does DTC set?
yes
2) Ignition off, disconnect ignition system test connector, ignition on,measure voltage on terminal A at the ecm side of the ignition test connector.
4.72 volts
3)4 to 6 volts, reconnect ignition system test connector. Disconnect distributur connector. Ingition "on", measure voltage on terminal A
4.72 volts
4) 4-6volts, faulty distributor connection or faulty distributor
looks like another person on the MSD purchase. My question is, the manual appears to diagnose this as a problem with a non-running engine.. How come mine runs?
yes
2) Ignition off, disconnect ignition system test connector, ignition on,measure voltage on terminal A at the ecm side of the ignition test connector.
4.72 volts
3)4 to 6 volts, reconnect ignition system test connector. Disconnect distributur connector. Ingition "on", measure voltage on terminal A
4.72 volts
4) 4-6volts, faulty distributor connection or faulty distributor
looks like another person on the MSD purchase. My question is, the manual appears to diagnose this as a problem with a non-running engine.. How come mine runs?
Last edited by sonomacrew01; Jun 23, 2006 at 01:40 PM.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Have you pulled out a few plugs to see their condition?
Have you checked that all the injectors are working and in good order? Is the throttle body nice and clean including IAC?
Fuel filter ever been replaced?
Coil-distributor wire not worn out on the back of the water pump?
Have you checked that all the injectors are working and in good order? Is the throttle body nice and clean including IAC?
Fuel filter ever been replaced?
Coil-distributor wire not worn out on the back of the water pump?
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by rick lambert
Sounds to me like you're in for a new OPTI, glad I have an earlier C4.
But, I did notice the knock counts..seem high to me.
But, I did notice the knock counts..seem high to me.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by Casethecorvetteman
Im not prepared to bet on it yet, sure it has the code, but that is no sure indication.