If you don't have one conected to
your ECM, will it cause some start up
problems 730 8d

 

If you have an automatic trans you might experience stalling issues when shifting from p to r or p to d without a p/n switch. Also if the ecm thinks your in p when your pulling up to a stop sign you may have some stalling problems. With a manual trans none of that is a problem. The IAC valve, in my opinion, is a must have to get the engine started in real cold weather.

 

I have the IAC but p/n switch is not
pluged in to the ecm. 700r4 trans
so the ecm can't tell if i'm in park or drive

 

Does the ECM think the car is in drive
all the time

 

Both of my TPI vehicles are manual so i never tried it but the p/n switch conects to ground in gear so without it the ecm thinks your in p. Try connecting the circuit full time to ground and seee how things go idle wise.

 

Anyone ever tried this, if so, did it fix any idle problems

 

i don't have the P/N switch hooked up in my car & i have no problems. it thinks its always in gear.
i did have it hooked up for a few days, i didn't like the surge i got when i shifted from park into gear so i unhooked it.

 

I don't think the P/N switch is your startup problem. Mine hasn't been hooked up and hasn't been a problem. In my last eprom burn I zero'd out the startup spark advance. Then I changed the coolant temp correction table to give around 5* SA at 20-45 degress and lower, 7* when colder. This is similar to what GM did in the ARAP calibration. My closed throttle SA and 100 kpa column below 1600 rpms is 26.02. When I went to crank the car it didn't fire right away. I had to open the throttle a little and then it fired. I think it was getting too much advance while cranking because until I made those changes it always started on the first turn of the key after a few revolutions. My initial is 10* BTDC which is what I have in the chip. What kind of timing are you using for colder starts?

 

Long crank times and 160 IAC steps when cold. My 100kpa column is
23.02. The iac steps when warm would go to 0 when it is fully warmed
up and would make the idle high. I set the idle like this so it wouldn't
die at open loop and cold temps. Spark is around 30-32 degrees cold.
Timed my car to 6 degrees and have that in the chip

 

884+3 a few posts up says it's in park, you say in gear, what is it in park or in gear

 

i believe it shows different with some of the other bin files.
IIRC, i have read on this site that the standard bins shows
in gear with it hooked to ground.
im running AUJP & for me unhooked shows to be in gear.
which bin are you running?

 

I have a standard shift and I was wondering if I should connect the P/N to ground or not. Maybe that would solve the problems I'm having. I am using a VSS and my EGR is blocked and turned off in my program.

 

Yes I'am running AUJP also so i'm in gear then.