ITB Cold idle issues
 

So I've got my itb setup tuned and running great. My only issue is that cold idle is crap. It will idle for a moment, and then die if the throttle isn't slightly pressed. It idles like a champ at 1k when its warmed up.

I know, I know, install an icv. However, my intake manifold doesn't have any provisions for this. What have some of you guys done to combat this? I just want to start my car and let it warm up without holding the throttle everytime. Afrs at idle are also decent at 13.0 (until it dies)

Car has a haltech e6x in it, for what it's worth.

13:1 is a little lean when cold, especially if your injectors are mounted in the throttle body.

Can you try adding ignition timing below your set idle speed? That way when RPM drops the timing ramps up to compensate.

Or you can just blip the throttle a bit to keep the engine running happy when it's cold. You know, the reason throttle blipping is necessary :) It always cracks me up when I see on TV shows or movies people blipping the throttle on stone stock cars where you could start them at 40 degrees below zero and walk away...

You could also do what I was thinking of doing on my car... choke cable :D

i'd go richer too. adding some timing is probably not a bad idea either.

Thanks guys. Injectors are in primary location. I tinkered with it today and upped the fuel a little more. Seemed to feel a lot smoother in idle. I'll test the cold idle in a day or so when I can drive the car again. I'll also double check the timing values.

its been my experience that it actually takes running through all the seasons to get the starting and cold idle stuff sorted 100%,

or maybe the blanket statement, the WOT stuff is really quick, and 90% of the time is getting all the idle/cruise/starting dialed in

Well, I've pretty much got cold idle dialed in. Still having an issue with voltage drop. Everytime I turn on the lights when the car is cold it can't hold idle and will hunt until it dies. I the ecu says it's only dropping .5 of a volt. I guess I can try and richen up that part of the battery/fuel table.

Also, I'm eating sparkplugs. If I take short trips, I'll come back to start the car a day later and it will backfire like crazy until I get the plugs to clear out. I'm wondering if my autozone battery cables aren't providing enough spark. (They are basically new, but hey who know's) I may throw on some magencore 10mm wires

what is your ignition dwell? it should be around 3.5ms. second thing to do is to clean up the injector/battery table, in ye olde days we had to do this manually, you may be able to find a dead time chart for your injectors now in ye moderne tymes.

the next thing is to just keep cleaning up the map

Not sure. I'll take a peek at it more tomorrow. Are you referring to the dwell setting? That is at 3.5 ms from memory. I'll double check though.

Now the voltage thing is only an issue when the car is cold. So up the fuel at 13.5 volts and maybe increase it a little bit at the cold start coolant temp?

Peejay: I'll check my timing at idle, but what do you think a good value would be to set the RPM range below idle at? just up it a few degrees off where it's at now?

It's more of a by feel thing. Like if you're idling at 0 degrees at 1000rpm then maybe try 10 degrees at 750rpm.

If you are already idling at the "happiest advance" (like 20-30 degrees at idle) then there is nowhere to go but down. The idea is that a cold engine needs more torque to turn, this makes the idle drop, so you need torque to increase when RPM drops to compensate. Corollary wise, you cannot idle at high amounts of timing because then you can't get a torque backup when it drops. So if you are already idling at large amounts of advance, drop that back down in the hot idle region and open up the throttles to compensate.

EFI that does idle speed adjustment with timing changes (it's faster than IAC) does this automatically but it is somewhat more predictable to
do this manually in the maps.

Mazda controls the S5 idle with timing. @750rpm its at -5 and -20, on the marks, but it'll advance up to 5 degrees if the idle speed drops, and retard up to 5 degrees if the idle speed is too high. it works ok, as long as you're in its range of control, if you're too high or too low it'll surge.

with the S5, Mazda does use a separate idle map for both timing and fuel, but with the haltech you can do the same thing in the main map, most of the time.

the Rx8 seems to be similar, although the leading timing is basically fixed, and it controls the idle speed with just the trailing timing. it is also running negative split at idle, so the leading is -5, like before, but the trailing can be +15.

so with an E6 haltech, you'd set the 1000rpm to -5 and -20 (or whatever it is), and then the 500rpm range to 0 and -15. also the 500rpm range in the fuel map should be the same or slightly richer than the 1000rpm cell. it might be nice to use the low rpm map style, if i recall correctly it gives you the 750 and 1250 rpm points, which are handy

So my ignition settings are currently set to Constant Charge- Falling: 4.0 ms. Could this be causing my fouling plug issue?
As for the timing, I need to double check the readings while its plugged in to the car

So I got the idle fixed. However, I noticed that it's always the front rotor that fouls or floods the plugs. I've visually verified spark, so I'm wondering if I have a leaky injector ot if the spark isnt sufficient. Compression is still good. Should I try trimming back the fuel on the suspect injector.

I don't have egt gauges but when the plugs foul, I can physically feel a difference in heat out of the exhaust. Although this difference is minimal when new plugs are in.