VAL113R

How do I advance the ignition on my car without changing the ECU ?

The car is a 93 WRX

thanks

dij

AFAIK,the timing is set on the cam belt then the ecu adjusts it.
There is no way to physically adjust ie no distributor or adjustment on the cam sensor.

Not sure why you want to do this but you would need an ecu upgrade to think about changing the timing.

VAL113R

thanks for the reply

the reason I want to know is because I am running a standard ECU at the moment but my ignition is advanced by quite a lot.

It's sitting at 37 degrees I am told as apposed to 16/17 degrees which is should be at ?

If I could figure out how to adjust the ignition timing then I might get to the bottom of the problem ?

unless you are able to help ?

thanks

JohnD

iTrader: (5)

I think you need to explain a lot more before anyone could help you here.
When you say 'sitting at 37degrees' at what engine speed? That is a perfectly normal ignition advance depending upon engine speed, load etc. JohnD

VAL113R

I don't really know much about the mechanics of cars but here goes

I bought the car about 2 months back and it had a missfire etc.

I had it in a couple of garages but the last garage it was in replaced the 4 coil packs, o2 sensor, spark plugs and a few other things. All to a bill of £750

I was told that the car was running a lot better but it still had the advanced ignition.

Over 2000 RPM the car runs ok they said but at idle its sitting at 37 degrees.

They said they had seen this problem before and it was down to the ECU and suggested I book the car back in for 'stage 2' to get a replacement ECU fitted.

After the £750 bill (I had not authorised the repairs I was expecting labour only work done and a bill of around £200) I didnt want to put the car back there.

My friend has a Link ECU in his car so he loaned me his working V1 ECU to try in the car. I had this fitted and the car is exactly they same.

I have also had the MAF changed and this had no effect.

The rev counter is broken in the car so I don't exactly know what the idle is sitting at but it is a lot higher than normal. I look like a learner driver sitting at junctions !

The car as said is a 93 WRX running a standard ECU. The only mods is a full decat.

Thanks

VAL113R

I have had it on a select monitor and it says everything is ok

Also the CEL light has not come on and have checked for recorded problems and its clear

The_Judge

That doesn't sound right at all. I thought MBT was used at idle, and I doubt MBT would be 37 degrees. Have you tried resetting the ECU (using the plugs, NOT disconnecting the batttery)? Also, are you certain the CEL actually works...?

JohnD

iTrader: (5)

Don't forget he said it is 'idling' much higher than normal and the rev counters broke!
JohnD

VAL113R

Hi all thanks again for the replies

The ECU has been reset properly a couple of times and this has made no difference.

The CEL does work as it has been on before and I had it into Subaru who read the code from the car. (the crank sensor had fallen off and the engine cut out.)

What's MBT ?

moonraker

I was recently on a course for work at Volvo Penta and one thing which came up on that course which I found interesting was that the magnetic pickup which is mounted on the engine has two wires. Yes, we can all easily see that. The interesting thing that was said was, if the wires are reversed it will actually alter the ignition timing. May be worth checking or trying another sensor to see. Shot in the dark, but you mentioned that the sensor had fallen off. Maybe, just maybe, somehow the sensor has got wired differently or something.....

Si

Trucker Ted

I would maybe get the timing belt checked,make sure its the correct belt and its fitted correctly and not a tooth out somewhere.

VAL113R

could the coolant sensor being wired round the wrong way cause this ?

The_Judge

Wouldn't any sensor wired the wrong way throw a CEL, just as if it had failed or been disconnected/fallen off? Surely the ECU would notice if the output from a sensor was outside of a set of parameters...?

MBT is minimum best timing. The following extract, taken from EcuTek's website, might help explain it...

Ignition Advance Map
The ignition advance map holds the timing values that may be added on top of the base map should the ECU decide to do so. The values are set so that base plus correction map values total the timing that should be used with the highest octane fuel that the engine will encounter.

At low engine loads, the ignition advance map contains no advance - this is the flat 'valley' of the map. No matter what the quality of fuel, the ECU will never advance the timing above the value in the base map. This is because the engine will not produce further power by advancing the timing - MBT (minimum best timing) has been reached. Advancing the timing further increases the chance of knock and also increases vehicles emissions of hydrocarbons and NOx.

MBT is the lowest value of ignition advance that produces maximum power.

At high engine loads, the advance map contains much larger values. This shows that the timing possible varies greatly with the octane of fuel being used. Under boost, it may not be possible to reach MBT. In other words, the more timing advance that can be run, the higher the engine power output produced - MBT cannot be reached before the engine begins to knock before the plateau is reached. This is where the active ignition timing excels - it allows the ECU to run the highest timing possible without engine knock. This results in high power output, good fuel consumption and low exhaust gas temperatures. At these high loads, emissions aren't relevant for passing government emissions testing procedures, since the cars are always tested at relatively light loads - a handy loophole for turbo cars.

VAL113R

Hi Judge

the thing is the car is not throwing up the CEL light ??