Advance Ignition to run cleaner

[tadaima]

Could I adjust the timing slightly advance to so that the engine runs hotter/cleaner? I know one must use Premium after advancing the timing.

Is there anything I have to worry about doing this? Does it lower the life of the engine? I assume I should get better gas mileage as well? Run Colder plugs?

The car is a civic engine (del sol).

 

[labman]

The factory spec is conservative. It protects the engine from pinging when driven enthusiastically. More conservative drivers can use more aggressive settings improving performance for occasional use and gas mileage. I have done with many of my cars and truck. I did have to do several valve jobs on the 1966 TR-4 I had. Of course, everybody else had to do valve job on them too. Never had problems on things with hydraulic valve lifters.

Remember, no engine will stand up to frequent pinging. Limit your driving style or your timing setting.

 

[Chris142]

Advancing the timing makes an engine run dirtier from an emisions standpoint. It makes the HC's, Co's and especially the Nox go up.

This is why your car doesn't run the same after an emissions test. The smog guy retarted the timing to get the car to pass.

 

[tadaima]

Hmm I thought advancing reduced emmissions, except for NOX since comb temps are higher. I guess I shouldn't mess with the ignition. I'm not into the power thing, I just want better mileage and something to clean the combustion chamber.

 

[n8wvi]

On every vehicle I could (can't do it on our modern engines

), I'd advance it. Heck, on my Impala, it was off the indicator plate. It was supposed to be at 8 BTDC, I had is 'somewhere' around 15. I had an '86 Camry that consistantly got 38 MPG. I have no idea where the advance was sitting, just put it so it wouldn't ping.

Dave

 

[tadaima]

38mpg on a camry that's great. Did you use premium gas? How long did you run these cars with advanced timing?

 

[wileyE]

Advanced timing puts more heat in the motor and can overheat the catalytic convertor on cars that use them. On one of my cars I could advance to the point of ping, then back off a couple degrees. It ran fine but would trigger a check engine light on a long steady cruise, code was for the oxygen sensor. It would reset when I let it cool off and restart the engine.

On your delsol I'd bet the timing as at 0 degrees and the computer decides on the advance from a map and a knock sensor. The computer will advance the timing until it hears ping, so anything you do to it manually will just be correct by the computer. On some cars you can hear this happen after the battery has been unhooked. You start the engine and hear little rattle ping, then it goes away.

 

[brianl703]

quote:

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Originally posted by wileyE:
It ran fine but would trigger a check engine light on a long steady cruise, code was for the oxygen sensor.

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My experience with oxygen sensors is that they usually start failing by giving a check engine light on long steady cruises (code was always "oxygen sensor read lean") I've had three fail that way so far on two different cars, usually driving at highway speeds for several hours made the light come on. (Both cars have two sensors because they have V6 engines, and on one of them first one sensor died, then about 20,000 miles later the other sensor died.)

Maybe advancing the timing is causing a marginal oxygen sensor to fail, especially if the code you got was a lean code.

EDIT: When that happened, resetting the code made it go away, at least till the next long drive. But I replaced the oxygen sensor as soon as I had time since it was obviously on it's way out.

[ December 05, 2004, 01:00 AM: Message edited by: brianl703 ]

 

[tadaima]

So sounds like newer cars do not have the ability to adjust timing since it is readjusted by the ECU through Vacuum advancing?

 

[brianl703]

quote:

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Originally posted by tadaima:
So sounds like newer cars do not have the ability to adjust timing since it is readjusted by the ECU through Vacuum advancing?

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Cars with distributor ignitions still can be adjusted. Apparently Honda still makes a few models with distributors.

Cars with distributorless ignitions cannot be adjusted unless a provision has been made for it, usually by adjusting the crankshaft position sensor. Most do not have any way to adjust the crankshaft position sensor.

Even if the car has a distributor ignition, using my 1988 Mustang 5.0 as an example, the timing is still under control of the ECU which can advance it. You can increase the base timing so the total timing becomes base + ECU advance.

In fact, when you check the timing on my Mustang, you remove a jumper which cuts off communication from the ECU to the ignition module, so the ignition module reverts to base timing.

Another way to advance the timing on newer cars with distributorless ignition is to use a chip. This actually also works on older cars with a distributor--I believe most of the chips available for the Mustang 5.0 advance the timing so you have to set your distributor timing back to factory spec if you've advanced it.

 

[mechtech]

Use as much advance as you can without spark knocking. An occasional knock is OK.
You will have better power and economy.