my motor has been fully tuned on a dynapack by a very reputable tuner the past two summers and used to have a dead on idle of about 1k-1200rpm.

setup is 81x89 ls/vtec with pro1 cams, running on a Neptune RTP.

i just switched the motor over to a new chassis, and changed to what should be a better header and also a 3 inch vs 2.3 inch catback.

im assuming the new exhaust setup would want more fuel.

the car does not like to cold idle and requires my foot on the gas typicall right about until the temp gauge hits the C line and then it will idle at 800-1000rpm's. Warm idle will sit perfectly at 1k for a bit but as soon as the thermostat opens it jumps up and holds about 1500rpm.

could this be a result of leaning out the idle mixture? unfortunately i do not have a wideband.

my only other option is that the throttle cable on my itb's is a tad tight, which i havent ruled out yet.

any input is greatly appreciated (will be emailing y tuner also)

 

forgot to mention, i do not run an IACV.

 

typically, yes, a laner mixture will idle higher, however you wouldn't want to pull it down by running it rich.

if you rule out everything mechanical (vac. leak, cable adjustment, butterfly sync., etc), you can control idle [somewhat] with ignition timing. less advance will pull it down, on a n/a car, i'd say you could go down to 12 - 14 degrees safely. that should make it fairly 'lazy' in the idle cells.

 

thanks for that.

syncing is not an issue, as its a later version of twm's with a barrel that runs between all 4 runners to keep them sync'd.

vac leak is possible, i just need to find a way to look. if anything its the cable, although its so odd, because as i find out last night it can actually idle dead on 1000 for a little bit, then all of a sudden it jumped back up to 1500 without touching anything.

it appears that any cells i would be idling in are at about 20 degrees of timing. im just not sure why it wont cold idle either.

 

It definitely can be lowered with timing. Also be sure to disable the Idle Ignition Correction, as that may be adding or pulling additional timing from your target in the maps.

We've idled plenty of setups with no IACV. You'll just have to tweak the maps, ECT fuel, and ECT ignition corrections for the warmup process until your setup is happy! Make sure it's getting enough air to sustain the mixture well during warmup.

 

this is what ive got right now (bear with me, im very weak in my tuning skills and neptune know how, i pay for tunes, i just want to fix an idle issue lol)

what is the "idle difference" value referring to?

i realized i also havent check base timing on the motor lately, which i guess is a good thing to check.





PS - thanks for the new mac version of RTP, its miles better than the last, as i finally got it to run for me!

 

No prob. Glad it's working out.

The Idle Difference is how far away from the target idle you are. Since you don't have an IACV these will likely be maxed out at all times.

 

Just send me over your current cal and I can send you something back that should help out.

 

just pm'd you back emailing you now...i forgot to the other night

i killed the car playing with it myself, figuring its just flooded/fouled out...stupid car.

 

john sent me a new map, didnt try to upload it yet, because new plugs didnt fix the no start issue.

could playing with the timing have killed a distributor or something?

now im really stumped.

 

Playing with the timing probably didn't do it, but you never know when those things will give. Check to see that you're actually getting spark.