I've been battling a stinky idle for a while now. This isn't just a rich exhuast, I'm talking about a grey cloud of smoke rising from my car at idle. The rest of the chip is just about as good as it's gonna get without a wide band. I've been trying to envoke open loop idle and can't for the life of me get it to work. I've messed with all the qualifiers with no luck, I also can't get the TCC control to work either, wounder if there is a conection. I've been digging through the hack and can't find any reason why either feature won't work.

I did finally get some time today to sit down with my car and burn about 20 chips just focusing on idle. I basically forced open loop globally not just at idle. Then tuned my idle for the highest vacume and lowest IAC counts. I was able to wack off about 20 IAC counts and gain 5 KPA of vacume. And most importantly get rid of the grey cloud. Then I turned closed loop back on and of course my blm's pegged over rich. I then fudged with the O2 offset and got my blm's back to 128. The problem is that the car still runs better open loop. Much more stable idle and less IAC counts.

I guess my question is were to I go from here. Should I keep trying to get the closed loop stuff to work properly or should I try to get the open loop idle stuff to work. And if so where should I look next to try to fix it? I have data logs of the car running in both open and closed loop as well as a copy of my bin if anyone wants to take the time to look at it.

Ohh yeah this is a 747 tbi setup with a 454 tb that has 75 pph injectors at 22 psi on a 355 with 9.5-1 comp and the cam listed below, it has a 111 lobe sep, All this mess has been transplanted into a monte.

 

Some basic stuff, have you replced the O2 recently? Also, have you checked for exaust leaks before the O2?

 

Find a new virgin .bin, and start again. Just use your existing BPC, and rethink / redo things.
Some times you can get so into a chip and make so many changes back and forth that you confuse where you are. So just need to take a deep breathe, look at your notes and start again.

And / or,
maybe, go thru the basics to see if somethings changed. Recheck the fuel pressure, min idle speed / TPS. Pull a few plugs and see what they look like. With the tune being off are the plugs still serviceble?.

And unless your real objective, and taking really good notes, 20 chips in a day is alot.

 

Well 20 was a bit of a stretch but I did burn 12 to be exact. I usually don't burn that many but I just decided to go old school and tune by smell and trial and error instead of believing what the o2 was telling me.

I've decided it's either a hard ware problem, plugs, wires fuel pressure, or I just need to start over with a new chip. I've been tuning on this one for about 4 months. A chip every other day or so just fiddling with things to see how the car reacts. I've been pretty carefull to go back to where I started but who knows I could have messed somthin up. I've been just paying attention to cruise and WOT since thats where I do most of my driving, I just recently decided to get the idle stuff right since I've got everything else about as good as i'm gonna get it without a WB. I've checked the simple stuff at least twice but it's probably something that I missed. I have a fresh set of pugs even though the ones that are in it are only 5000 miles old. The plugs have been on for a year but that doesn't seem too long to me. I'm startin to wounder about the regulator since I've had to cut the spring a bit to get the 22 psi that I want. I'm near the end of it's adjustability and if I go too far the FP does go funky. I thought I had it set pretty safe.

Just need to take a step back and clear my head and go at it again.

 

Starting with a new .bin even if the original one, does just that.

 

Your right Grumpy, Thats my plan of attack for the various open loop and tcc problems. I'm just gonna start with the asdz bin that I have a hack for and plug in my VE and Timing tables.

However I did realize that the wierd intermitten miss I was attributing to my VE curve being off is actually something else. I got my VE plus minus 2 blm on my last burn and got my pump shot pretty much figured out and my idle is now pretty decent, actually this is the best my car has run in a while other than this miss, and the other problems with open loop idle and tcc control. The miss is completely random and my blm's and my PW don't move a bit when it happens. My timing curve is the same one I have been running for months with no problems, with the exception of retarding it 2 deg. This leads me to suspect plugs, wires or other ignition components. I also magically came up with 25 to 45 knock counts in the upper rpms that has never been there. That also sounds like something on the ignition side breaking up. So i'm gonna try some new plugs, and maybe wires and then try the fresh start aproach once I decide whats causing this miss.

Thanks for the help I was just frustrated.

 

When your really, close to perfect with a C3 TBi, you'll get that. There is a snafu that explains a very random once inna while *incorrect PW*. Generally running slightly rich or lean mins it.
Snafu, meaning, I think I know the reason, but really don't have enough documentation to say it as fact.

 

Well thats what I get for not checking the basics. The plugs were pretty much caked in crusty oil leftovers. I'm burning about 3 quarts of oil between oil changes so the plugs got fouled up pretty quick. Funny thing is you never see a puff of blue smoke. Any way my intermitten miss is gone and my VE table needs tweaking again. It does idle much better even with the blms in the mid 130's. Also my HP curve on my barrowed G-tech II is now a curve instead of a jagged line.


Go figure.

 

Hey grumpy you car to elaborate on your "snafu". Now that I have my VE back in line I'm getting that intermittent miss again. Now as bad and not as often but it's there. It's not really a miss but like a skip in the motor.

 

When you run a system on interupts, sometimes you might interupt something.
You might add just a smige of fuel at idle and see if that helps to min. it.
And if say if your at 47.5 K/Pa at 800 RPM, that both the 45 and 50 K/Pa entries match.

 

I'm bouncing around between 45 and 50 kpa at idle so that could very well be the problem. Ahh can't wait to get the speed reader, I might actually be able to catch the problem in action.