spark table in sd mode

[BigBoy]

Ok im a newb but this stuff is coming to me farely easy with this forum, but my question is in my 2001 silverado spark tables its cylinder airmass g/cyl by rpm well from what im seeing is it looks like its reading the cylinder airmass from my Maf which is disabled but is laying aside of the engine bay for the iat.

in my log timing is 28-32ish which is right wiht my tables but in never goes over .12g/cyl which thats probabley just wind running through it when im driving. My dynamic airmass is corrisponding right along with my map, which is .30 to .60 normaly

What do i need to do in order to get this corrected so my timing will be correct along with engine speeds and correct airmass.

Thanks Ray

[S2H]

what did you do to "disable your MAF"
and when you disable the maf, it reverts to the Low Octane Table Unless you run a custom operating system that allows for full function of the High and low octane tables when in Speed Density.

also there are things that can cause the dynamic airflow to read half the value...make sure you remove the MAF from the table display when you are in SD
can you please post the Log and a copy of your tune.

[BigBoy]

Here are my files, also i was trying to get it to were it will start without having to have air flowing though the maf for it to fail. i know i need ot zero out the maf table and at the lowest point put 12-12.5, would this table be the maf calibration table or is there another table i am overlooking?

[S2H]

the car is seeing the right values.. its just plotting wrong in the scanner...
try taking the MAF out of the table display...remove it if you arent actually using it..
then you should see the right dynamic cylinder air
you also dont need the calculated cylinder air PID for what you are doing at the moment...


you dont have to zero out the MAF table.. once you set the fail to 0 it ignores the MAF table completely.

[BigBoy]

yea but for some reason after i write to it i have to blow some kind of air though the maf for it to fail. after the first initial start it will start fine everytime after that.

[Frost]

...

you dont have to zero out the MAF table.. once you set the fail to 0 it ignores the MAF table completely.

Some OS's are slow to code though. I zero the table and add in 12-13g in the 0Hz cell (first MAF cell). This lets the car start right up, idle and code without goofiness. Most OS's don't seem to need the extra second, some really do.

[Nick 2K2 SS]

I believe you also need to go into the engine diag and set the maf fail code to light up on the first failure instead of the second failure.

[BigBoy]

Ok i have tried everything that yall have said to and then some. No luck. Its drving me nuts. I always have to get someone to blow across it to start. I dont remembrr if i mentioned that the maf is sitting aside by itself not in with the intake so no air flows across it once the engine starts.

[Russ K]

That's because your Maf is not installed on the vehicle. For P0103 to set, the Maf has see airflow. Install the Maf, or remove one of the Maf reference wires. But your still not going to get an accurate air temp reading with the maf just laying in the engine compartment.

Russ Kemp

[S2H]

That's because your Maf is not installed on the vehicle. For P0103 to set, the Maf has see airflow. Install the Maf, or remove one of the Maf reference wires. But your still not going to get an accurate air temp reading with the maf just laying in the engine compartment.

Russ Kemp

LOL.. I forgot about that...

yes.. leave it in the intake tract if you can... it has to see some airflow to actually fail...

if you really dont want to leave it in the intake tract, then go buy a little 12v computer fan and wire it up to a 12v ignition source and slap it right in front of the MAF... then you can "simulate" a false airflow going thru the MAF and it will fail so you can really get into SD at startup

[Frost]

The MAF should put out SOME freq even at 0 airflow, so setting the fail freq. to 0Hz, Setting p0101, 0102, and 0103 to fail on first error, and adding in a bit at the bottom of the MAF table the way I mentioned should get SD; even if it's plugged in. I haven't had a problem doing this.

[BigBoy]

thats what i would have thought to, even doing all that. in my dtc on my scanner its only showing a p0103 code i dont se a 101/102. how do the boosted guys do this do they use a slot type maf?

[Frost]

0103 is what you SHOULD see... since fail is set to zero, ANY reading will be defined as a high reading. That puts you in SD. What's the problem?

[BigBoy]

i just gotta have someone blow through the maf while i start it to get it to run after i write to the computer after that its fine but it becomes an issue when im by myself.

[S2H]

i just gotta have someone blow through the maf while i start it to get it to run after i write to the computer after that its fine but it becomes an issue when im by myself.

either disconnect it fully and buy a different IAT sensor, or put it inline and leave it failed...
it doesnt get used for fueling if its inline and failed... but it needs the airflow to fail it.