ignition timing idle at 25°
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ignition timing idle at 25°
Hello,
checked the ignition timing last eve and found out that the ignition timing at idle is at 25° ! in the workshop manual they say only like replace your ecu !
only mod on the car is a catback buddyclub exhaust. new throttle body and new engine 2000 miles ago.
anybody with same problem ? any suggestions ?
cheers,
K.
checked the ignition timing last eve and found out that the ignition timing at idle is at 25° ! in the workshop manual they say only like replace your ecu !
only mod on the car is a catback buddyclub exhaust. new throttle body and new engine 2000 miles ago.
anybody with same problem ? any suggestions ?
cheers,
K.
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Joined: Jan 2009
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Why should the ECU be defective and gives itself an idle ignition value of 25 °?
The tables are hard-coded into the cpu. How could a defect work inside it?
I'm pretty sure it's a sensor, because the ECU is feed by the sensor values.
In your case I'm going for a faulty MAP sensor. Probably it has strong fluctuations in idle (where vacuum is high). These measures shows the ECU that higher load is present and that pre-ignition must be set to 25°.
The tables are hard-coded into the cpu. How could a defect work inside it?
I'm pretty sure it's a sensor, because the ECU is feed by the sensor values.
In your case I'm going for a faulty MAP sensor. Probably it has strong fluctuations in idle (where vacuum is high). These measures shows the ECU that higher load is present and that pre-ignition must be set to 25°.
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t/b body is new so map sensor and tps are too !
ignition timing values variates from 5° to 25° at idle. I tried the ecu option first because I had someone who had one and workshop manual said so.
but why doesnt the ecu show any error codes ?! I connected an obd and there are no error codes and the only "unsual" thing I could read was the ignition timing. any defective sensor should be showed by the obd, shouldnt it ? first thing what came in mind was a sensor and after reflection I figured out that it could be a lot of sensors like any temp sensor or even ignition coils, sparks plugs.. but again why doesnt the ecu show any error code ?
ignition timing values variates from 5° to 25° at idle. I tried the ecu option first because I had someone who had one and workshop manual said so.
but why doesnt the ecu show any error codes ?! I connected an obd and there are no error codes and the only "unsual" thing I could read was the ignition timing. any defective sensor should be showed by the obd, shouldnt it ? first thing what came in mind was a sensor and after reflection I figured out that it could be a lot of sensors like any temp sensor or even ignition coils, sparks plugs.. but again why doesnt the ecu show any error code ?
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The ECU doesn't give an error code because it doesn't "know" that there's something wrong.
Have a look in my datalog of my old faulty Map Sensor:
http://www.s2k.de/forum/attachment.php?att...entid=544144281
If you installed a new TB is the vacuum channel to the MAP sensor clean and all the way sealed? I had trouble with an Skunk2 TB because a small part of this channel was not closed when attached to the manifold.
Have a look in my datalog of my old faulty Map Sensor:
http://www.s2k.de/forum/attachment.php?att...entid=544144281
If you installed a new TB is the vacuum channel to the MAP sensor clean and all the way sealed? I had trouble with an Skunk2 TB because a small part of this channel was not closed when attached to the manifold.
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I recommend to strictly go methodically for troubleshooting your problem.
The Honda ECU is programmed with fixed tables for the ignition (Ignition Maps). These cannot be modified.
There are basically three parameters that determine the value that is taken from these tables: engine speed, manifold pressure and TDC Position.
There are also some correction factors such as temperature, throttle position, idle speed control. But all these corrections shouldn't let the ignition jump as much. So please check the sensors - not the ECU.
Engine Speed sensor should be fine, otherwise you will get an error code, because the ECU checks for plausibility of this input value. And a quick jump from 1,000rpm to 3,000rpm withiin milliseconds isn't plausible.
TDC Sensor could be faulty, I don't know yet how to figure this out and what else would be affected if it goes faulty. The older engines had 2 of them. Maybe they worked fail-proof.
MAP Sensor is my best bet on your problem. You should check the tightness of the MAP channel of your TB.
As I have already written, I had that same idle problems when I installed the Skunk2 throttle, because their S2000 TB does not fit at my intake manifold.
The Honda ECU is programmed with fixed tables for the ignition (Ignition Maps). These cannot be modified.
There are basically three parameters that determine the value that is taken from these tables: engine speed, manifold pressure and TDC Position.
There are also some correction factors such as temperature, throttle position, idle speed control. But all these corrections shouldn't let the ignition jump as much. So please check the sensors - not the ECU.
Engine Speed sensor should be fine, otherwise you will get an error code, because the ECU checks for plausibility of this input value. And a quick jump from 1,000rpm to 3,000rpm withiin milliseconds isn't plausible.
TDC Sensor could be faulty, I don't know yet how to figure this out and what else would be affected if it goes faulty. The older engines had 2 of them. Maybe they worked fail-proof.
MAP Sensor is my best bet on your problem. You should check the tightness of the MAP channel of your TB.
As I have already written, I had that same idle problems when I installed the Skunk2 throttle, because their S2000 TB does not fit at my intake manifold.