My 01 C5 was tunes in speed density. When I unplug the MAF the car dies as soon as I touch the throttle. If I leave it plugged in and remove the air bridge so I can see the throttle plate, it is the same. I thought a speed density tune allowed you to not need the MAF?

 

Is your thermostat integrated into the MAF? If so you need to convert to a pre-2000 I think that has the thermostat outside the MAF.

 

yup. if it's a 5 pin MAF, you are disconecting your IAT when you unplug the MAF.

 

So what does that say when I leave it plugged in and remove the air bridge exposing the throttle plate and it does the same thing?

 

if taking the MAF out of the intake flow path has the same results, then I'd say you're not in SD

 

Here is my tune if anyone want to look

www.hotrodz.org/vette/files/tune

 

what software are you using

 

Tuner Cat. The tune that he used was EFI Live I think, I read it with tunercat on my laptop.

 

im pretty bad at navigating through tc, but i will say the maf fail is set at 1hz so it probably is in SD mode...i dunno what else to tell ya.

 

The only thing that got me is the MAF sensor Air Flow vs. Output Frequesncy is still there. Even without the AIT sensor plugged in that is not enough of a reason that the engine will not run once the throttle is touched.

 

Scan the car for DTC's. If you don't have P0101, P0102, or P0103 then you're not in SD.

 

hmmm, yeah I took a second look, he's got them set to no error reported & the ses light disabled, so maybe it ISNT going into speed density. I would say turn the ses lights back on for 101,102 & 103 and set them to no mil, but definitly look to see if the codes set at least to throw you into speed density.

 

the computer needs to throw a maf code, in order to go into SD, if you make the computer not recognie that code then it will try to use the MAF only, and not run. let the computer recognize the code, and just turn of the light only. and take you original 5 pin maf remove your all the pins except for the two pins (on the far left or right) for the IAT, and rip out all the MAF, be carefull not the damage the little IAT tab. i have done this on three cars, two of them being mine, works great.

 

will the service engine light come on when unplugging the MAF if you are using SD mode ?

 

it depends on whether or not the MIL light is enabled. If the car was bone stock, then yes.

 

Which tune is better for drivability on a Nicely modified engine (over 500 RWHP) MAF or Speed Density?