Intake Air Temp resistor experiment.

[fabrio]

Originally Posted by usedgeo

Oddly enough my Saturn does not show an ignition retard with hot air. I hope that is not an instrumentation error too . That is why I expect the stepper motor controlled EGR might be a factor. In any case it only acts up during moderate acceleration. If I go on down with the throttle it runs very well. The increased throttle could affect both mixture and EGR. I have never heard the engine ping. If it does I will need to look for the knock sensor too .

Usadego, I do not understand, as you make to see the ignition delay. Which instrument uses for this check?

[usedgeo]

Originally Posted by fabrio

Usadego, I do not understand, as you make to see the ignition delay. Which instrument uses for this check?

Scangauge II http://www.scangauge.com/

You might want one of these . Lots of useful information can be displayed.

It is "the must have" to get exceptional mileage.

[fabrio]

exceptional instrument usedgeo

a question: during the motor erogation (rpm) the ignition time change or it is constant?

normaly, the ingnition timing change when the rpm motor change.
You use a potenziometer for change the iat value? and, witch is your procedure for control the ingnition time?

I suppose that the your verification procedure is following:
verify of ignition time when you change the IAT value at constant RPM and load....it is true?

[wireless0ne]

well i first ran a 150 ohm resistor and the car ran like hell, it is a saturn by the way, so i went in the opposite direction and installed a 1000 ohm resistor, i was going to check what the ecm is reading intake air temp wise but my scanner doesnt seem to work in the car, or the diagnostic port has no power, i'll check this weekend.

[usedgeo]

You need to browse other sections of the site when you get the time. I think aero mods are more important than tweaking with the engine. Even so I have started tweaking with the engine.

I changed resisters with the engine running at several different RPM's in neutral. There was no change that I could see. I have given up on resistors for now and am running real hot air. I am running a true 180 deg. F intake air temp when everything is working right.

I just let the computer run the timing. It varies from about 10-34 degrees depending on load and rpm. At 60 mph and 10-15% load I run around 33-34 degrees advance. It never runs more. It may retard sooner under load. I have not taken the time to map the timing with respect to load and temp. I just looked at the peak ignition advance.

Originally Posted by fabrio

exceptional instrument usedgeo

a question: during the motor erogation (rpm) the ignition time change or it is constant?

normaly, the ingnition timing change when the rpm motor change.
You use a potenziometer for change the iat value? and, witch is your procedure for control the ingnition time?

I suppose that the your verification procedure is following:
verify of ignition time when you change the IAT value at constant RPM and load....it is true?

[cfg83]

Telco -

Originally Posted by Telco

Scangauge takes its readings from the computer, not its own sensors. IAT would be used to calculate how much air is coming in, so the scangauge would be fooled by this. Once the car goes into closed loop, it really only looks at the O2 for a fuel/air mix. The IAT tells it air density, but that only matters on warmup. Once the O2s take over, the computer doesn't need any other inputs. The scangauge would be fooled since it takes several different readings to calculate a guess at the mileage based off an algorithm, not an actual measurement of fuel economy. Skew one number, and the answer is wrong.

...

This is good to know. Where did you read/hear that the Scangauge algorithm does this?

CarloSW2

[cwa]

Sorry for moving away from current thread. I have used IAT MOD for last few months, but the result is consistant. I used 220 ohm initially and I got 20% improvement during first week and then it went down. THen I swtiched over to 470 ohm , got 12% improvement during first two weeks and and it went down. I got some improvements when I reset the ECU (Taking Fuses off for 5 minutes), but I dont want to repeat it.

Has anyone have any suggestions?

[SVOboy]

What kind of car do you have? Seems like it is compensating for the changes...

[cwa]

It is Suzuki Swift 2004 Japaneese Domestic Model (1.3L, 4 Cy engine). Unfortunately it is not compatible with Scanguage so that I cannot use it. As you said it is compensating, may be advancing the timing as it has VVT engine.

[SVOboy]

The new swift is so kick butt, I've been meaning to post a picture on here for a while so everyone could marvel at the japanese wonder, but I've been forgetting.

Your car just must not like it,

Post pictures!