Max_Spd

iTrader: (78)

Ok after spending a couple hours reading through stuff and not really getting anywhere close to a problem resolution i want to post some problems i am having to see if any of you can resolve them from experience...Tuners welcome!!!

I have all emissions removed, that includes thermal wax assembly and all the AWS stuff and every other gizmo that the car does not really need!!! The car is Street ported with 850/1300 injector set-up. Power FC engine management.

The questions:

1.
On cold starts i can't keep an idle, i have to stay in the car for a good 3-4mins until the car reaches temps of 140F ~ 60c-70c i think and keep the rpm up in the 1500-2000range...Once warmed up everything is perfect!!! what are some successful setups you guys use to have the start and run on its own at idle when its cold, i know there is a setting on how much more fuel is used from -30 to +80 with +80 being 1.00 and 1.00 what are you using in your unit that works i know 1.57 will stall the engine and not make it run when cold, how much lower to 1.00 should it be at like -30c - 10c 0c + 10c + 30c + 50c or whatever the Power FC has listed this is all from my head/memory and i dont have a wideband that i can tune the idle with

2.
What is the absolutely the correct way to adjust the voltage on the TPS? I can adjust the TPS voltage to 1.00-4.92 and .42-4.32, which is in spec! This is how i see everyone setting the idle TPS:
Backing the main idle lock screw all the way out to just touching the top of the cam/main stop. and 2nd butterflies fully closed with preset on just at closed position. There seem to also be a secondary or should i say a factory preset primary single butterfly position stop on the bottom firewall side of the TB, adjusting it also modifies the angle of open/close position but the issue is that with it set at factory and and air bleed screw on the bottom turned half out/closed or fully open the idle is still too low and the car dies unless i start screwing in the main butterfly screw on the top/left of the TB in which gets me to the 850-1000 mark that i am looking for!

Here is my question: does the TPS angle/voltage need to be adjusted once the idle had been already set with the engine rinning all warmed up to desired (perfect idle) and the screw put down to open the plate more for the idle to be in spec. Or before adjusting the idle screw in my case? as i think the spec of .75-1.25 and .1-.7 is for when the idle is set or when main butterfly is closed? keep in mind MODIFYING the idle after the TPS has been set at the absolute minimum will now make the idle TPS voltage above the .75-1.25 and .1-.7 closed idle range and if i need to modify the TPS position i can probably get the low range set in spec, but high end I cant being that the acceptable is 4.2-4.6 i think and i can only get 4.1 and thats max adjustment angle!!!

I did have an idea, what if i let air in via the secondary plates open a bit as they have some room to be opened and wont interfere with anything? what do you think?

Thanks for reading this long blog like contemplation, i hope your answerst willl help myself and others who might have similar modifications!!!

arghx

iTrader: (3)

you removed the factory cold start idle system and now you complain that it won't idle cold? this "mod" used to be popular among the 2nd gen crowd, until everyone realized what a pain in the *** it is.

Do yourself a favor, and this is coming from someone experienced with idle headaches.

Buy an unmodded TB which still has the thermowax and dashpot and all that jazz. It will keep the car from stalling when cold and when moving around at low speeds (dashpot prevents the throttle plates from snapping shut on decel). The double throttle system isn't really needed though. Then you will need to adjust the primary butterfly screw a little bit but mostly the air adjust screw under the TB to add idle air. Then you will need to set your idle speeds to 0 in the datalogit and manually adjust fuel and timing because you have no ISC.

It's going to take you a long time to get it to idle right, especially under cold and hot starts.

1QWIK7

iTrader: (33)

I did the TB mod and i dont have any issues with cold start.

Idle is slightly lumpy but it never stalls or never wants to stall.

On another note, how does it take 3-4 mins to get to 140F temp in northeast weather?

It takes me literally like 10 minutes to see 140F.

arghx

iTrader: (3)

I re-read your post and noticed you don't have a wideband. Get one.

oo7arkman

iTrader: (2)

If you have not already touched it, you should leave the butterfly screw on the firewall side alone. The two stop screws on the front should be adjusted so that the butterfly's are closed but not sticking. The Air Bleed screw on the bottom the the TB should be all the way IN and then out about 1/2 turn to begin adjustment.

As far as the TPS, with these settings on the TB itself and with the car cold you can get the TPS to where it is reading in spec. Start the car and get it to operating temperature and use the Air Bleed Screw to adjust the idle. Then recheck the TPS to make sure it is still in spec and adjust as needed.

THIS is all of coarse pending that your PFC is set up to run the injectors you have installed and the bottom end of your map has also been modified for those injectors.

If that does not work, I think you should seriously consider arghx's advice and replace the TB with one with the wax still on it. AND you have these injector mods and NO wideband!!?!?! may the gods be with your motor...

arghx

iTrader: (3)

if you have removed your ISC you solve one set of problems (surging and sticking) and create another set (rough idle and stalling under some conditions if fuel, air, and timing are not carefully tuned along with their respective temperature correction maps).

Even though they may be a pain in the *** sometimes, Mazda put those idle control systems in there for a reason, and removing them does have consequences. The ISC idles the car up when accessories come on (probably not an issue in your case) but it also adds extra air in on decel and hot starts to prevent stalling.

I for one have tuned rock solid idle both with an ISC and without, and both ways have their drawbacks. There are no benefits to removing your thermowax except a little less plumbing.

Max_Spd

iTrader: (78)

Thanks for the detailed replies guys ;-)

Just to clarify some things, the car was tuned by Ray @ PFS for the injectors and power,

Due to simplifying and cutting out emissions controls and harness i have removed the power to the ISC valve, but being that Ray found out that the ISC was not working, he tuned the car in warm weather and got the idle set @ 1000 for all 3 instances and i have no AC anymore!!! And even though i have a light 9lbs flywheel, and injectors set up at <1500 to add fuel on decel on the Power FC gives me no problem in driving/idling/slowing down when the car is warmed up!!! But as i said, the car was not tuned for cold starts with the current settings, i was not too familliar with the fast idle cam even though i blocked off the coolant to the TB, and now that i decided to simplify the TB by removing the hot wax assembly as well as the fast idle cam out i want to adjust my idle to a near perfect TPS.

And so what you are saying is adjust idle when car is warmed up to say 900-1000RPM via the secondary butterflies and air beed screw half a turn out and then use that as the lowest starting point on the TPS to be @ 0.75-1.25 and .1-.7

My idle was tuned by Ray, but in warm conditions and i think that i am really all set and dont want to buy a wideband just for tuning idle as i know those sensors wear out quick in when driven on, but i strongly beleive that getting the TPS in perfect spec with 1000rpm idle and the fuel settings based on water temp will keep the car from stalling out, i know i messed with it a little the other day and was able to hold idle at 50-60c when before it could still stall

Also is the ISC controlled by the ECU via negative grounding - or power +?

Max_Spd

iTrader: (78)

I may be off on the minutes, but i keep the rev @ 2000 until the 140f mark then i know i can let go and it wont die!!!

Also can you give me your readings/settings for the idle/rpm as well as water temp fuel correction from the Commander....PLEEEEEASE

GARCO MOTORWORKS

With out the hot wax rod and cam You CAN make it start cold and stay running ,I have two programs .One will start good and the other will not .When I have time I will match the bad one to the good one in the cold start area .The good program will start the first try and idle steady .When the water temp gets up I can drive away slowly .The bad program will start but will not stay running unless I work the throttle untill warm . I am using 850cc and 1680 cc injectors with a PFC .

arghx

iTrader: (3)

I guess if you are willing to have it idle at 1000 you could definitely make it idle cold. I just prefer it lower.

It's hard to figure out without a wideband. If it's stalling because there isn't enough idle air, I would try to screw the air adjust screw out first (the one between the two TB studs) because it doesn't affect your TPS voltage. But that is going to make it idle higher when warm. The general advice is to only have that air adjust screw open 1/2 turn or so, but that is on a car with an ISC. It's all fair game when you run with manual idle control.

Overall though It's never going to idle cold with perfect consistency under all conditions when you remove the thermowax. It's just a tradeoff of the simplified setup you are running. You need to keep adding air and fuel until it doesn't stall, then set your TPS when it's warm. That's about all you can do, especially without a wideband. You'd be happier with the results if you had a wideband though.

What you really should do is get a datalogit, set all 3 idles to 0 (only DL can do this, it gives you full control of idle timing when ISC is removed), then advance your timing in the idle area. That will improve stability greatly. Right now it's probably idling at 5 or 12 degrees of advance. Without an ISC and at 1000 rpm I would put it closer to 18-20 degrees. With no ISC, big street port, and 850 idle I ran 20 degrees at 850rpm. You also need to turn off the cold start ignition retard if they didn't do it at PFS. It retards the timing something like 15 degress until 65 C or so, which could be part of your problem.

Max_Spd

iTrader: (78)

Yeah when its 80+ the water temp correction is 1.00 and 1.00

but lower temps its going up to say +50 it will be 1.05 and 1.07 or so and so forth :-/

I just want her to start and idle on her own, i dont drive her until she is at 140 or better!!!

arghx

iTrader: (3)

You need to advance the timing, and for that you need a datalogit. It will help a lot. With no ISC I changed to BR10EIX plugs and the damn car wouldn't even idle until I advanced it 10 degrees. It's that sensitive. I also noticed that it started with fewer cranks as well.

You don't have the proper tools to get an ideal idle. Keep turning the screws (air adjust under the TB and the primary throttle plate screw) until it idles, then check your TPS. There's not much more I can tell you. Go into the commander water temp table and set both the left and rightmost column higher. The left column is for a PIM value of about 5000 (maybe 16" of vac?) and the right value is for about 15000 PIM value, or 7psi. The PFC interpolates between them. A higher rpm idle may be pulling less vacuum (higher PIM value) so the right column may have more effect on the cold start correction than say a car with a 720rpm idle.

Max_Spd

iTrader: (78)

Yeah i know i dont have the tools :-( and it wont be until a few months till i can drop off the car at PFS to tune cold starts and cold idle with the current set up!!!

Thanks for your help btw...Also by messing with the main butterfly i am in term messing with the voltage reading at the TPS and the lowest reading range is suppesed to be set at perfect idle...correct? TPS is to be adjusted after the car is warmed up and idle is set at perfect rev?

oo7arkman

iTrader: (2)

Yes, when you adjust the main butterfly screw it will mess with the tps setting.

No, you should warm the car up to normal operating temp, shut it off, then adjust the tps with the key in the on position. Lower reading is with 0% throttle, higher reading is with 100% throttle.

Max_Spd

iTrader: (78)

Ok yeah i guess there was a misunderstanding...

1) warm up the car to operational temps

2) adjust the idle with screws and air bleed half turn out (more if needed max of 4 turns)

3) (turn off the car/ignition still on) adjust the TPS to spec with min range set at adjusted idle setting and full range at fully open throttle...

Got it!!!

Max_Spd

iTrader: (78)

Ok so what does your water temp fuel correction map is set at on your commander, i would really appreciate those numbers for my comparison, im talking about people who have removed the thermal wax/fast idle cam and maybe ISC

Keep in mind i still have the dashpot, it works well and does prevent stalling/drastic RPM drop

One last thing = ISC (also my previous question) does the ECU control the ISC via grounding or voltage as i know ISC shares power with a gray emissions solenoid plug :-/ (which i removed)

arghx

iTrader: (3)

the ISC is pulsewidth modulated, you'd really need an oscilloscope to read it.

the thing about the water temp table is that we don't know what he did with the air temp table, which also affects the mixture. A water temp table really should be matched to the air temp table, something that can't be changed without a datalogit.

Max_Spd

iTrader: (78)

I have access to a datalogit, my friend has it!!! If i absolutely need it, but for a simple colder idle fuel mixture im sure it should be fine with lean><rich mixture its only running at 1000rpm Me thinks :/