onesus

I tried to tune the idle speed of my RX7FD. My engine is stock, 550/850 injectors. My mods you can see in the signature. I want to use ISC, so I adjusted the throttle body screws. I opened the AAS 1/2 turn and reinstalled the elbow. After reset of the PFC, I performed the idle learning procedure (O2 FB was disabled, Idle IG CNTL was enabled).

I already cleaned the Idle Air Control Valve, I measured it with an ohmmeter and itīs fine. I adjusted the TPS, too. The voltage is within mazda specification.

The idle speeds are stable at the values I entered in the table. But my car is bucking . I tried some different IGL/IGT timings, but it doesnīt matter what i enter, nothing changes. My engine runs too rich, but itīs not possible to me to get the AFR leaner. All the vaues I enter in the INJ-map, seems to be ignored by the PFC. Is it possible to change the AFR for idle speed with enabled ISC?

Then I tried to set up for manual idle speed. I disconnected the Idle Air Control Valve and disabled Idle IG CNTL in Datalogit. I set all three F/C speeds to 1400 and the idle speeds all to 0. I adjusted the AAS and TAS to an idle speed of 1000 rev. But there are still misfires and the car is bucking. I tried different IGL/IGT timings but it seems not to help. AFR is still about 12 and I canīt change it to a leaner mixture, why? My wideband seems to work fine. In all other areas i can see the effects when I add or remove fuel, but in the idle area it seems not to work! I know of the hidden idle-map, but with a manual idle speed it must be possible to override it, right?

Chris

cewrx7r1

iTrader: (2)

Is the air pump removed, and the O2 FB Switch still turned on?
Did you run the recalc function, and the O2 FB Switch turned on?
Is you map sensor correctly selected, and functioning correctly?
These and others can cause your problem.

arghx

iTrader: (3)

Misfires and bucking... sounds like a tip-in/accel enrichment problem?

onesus

the air pump is removed. Oē FB Switch is disabled (I hope you mean the DL-option under settings1 - function select or is there a switch somewhere else?). This function is disabled all the time, because Iīm using a wideband. The only function I selected ist seq. turbo cont.

Iīm using the stock map sensor and I have selected the 1.Normal - Option with default values. It should be fine, I will check the voltages of the map sensor.

I noticed, that when I turn the AC on, the engine is running better. When I drive the car and the engine is warm itīs bucking. But when I turn off the engine, wait a while (10 min) and turn the engine on again, it runs ok. And after 1 min the bucking and misfires are there again.

Chris

cewrx7r1

iTrader: (2)

Maybe one of your temperature sensors is bad.
Air temp, water temp, or fuel temp. Default value for them is to run rich.
This makes the engine run better cold than hot.
Use the monitor mode or FUNCTIONS screen to check them out.

arghx

iTrader: (3)

You have a Datalogit it seems. You should post logs of the problem. Go into the monitor window and select only "Advance" but if you have a wideband hooked up also select "Aux"

onesus

here are the voltages of my sensors:


engine off engine on, cold engine on, warm
PIM 2,52 1,38 1,42
VTA1 0,48 0,49 0,42
VTA2 1,12 1,08 0,96
VMOP 1,17 1,17 1,15
WTRT 2,92 2,72 0,75
AIRT 2,92 2,09 1,46
FUEL 4,21 4,23 3,85
O2S 0,01 (removed)

I played a little bit with the AAS to find the best position. Now itīs not possible to me to complete the idle learning procedure. Rev jumps up and down, but normally it stabilized after 15 seconds. Now after 10 minutes itīs still going up and down. Donīt know whatīs going on. I set the AAS back to the position it worked ok, but now it doesnīt work.

Has the engine to be cold, when I start the idle learning procedure?

What has the voltage to be for FUEL?


Chris

onesus

Thereīs a little mistake in my previous post:

the first voltage value is, when the engine is off, the second one is when the engine is running but cold and the third value is when the engine is over 80°C.

Chris

arghx

iTrader: (3)

.

onesus

here is a log

arghx

iTrader: (3)

Is this the correct log? You are idling steadily at almost 1200rpm (which is pretty high). AFR is right around 12:1, which is about the richest most people would accept on a rotary. The ignition timing is fixed, the ISC valve is fixed, the vacuum signal is stable. Besides the high idle speed I don't see anything...

onesus

Thatīs the problem! As I mentioned before, I switched to manual idle, because of the hidden map. With ISC switch on, all my changes in the INJ-map seems not to affect the AFR (only idle area, cruise area works fine). Thatīs why I pulled the ISC valve connector to go manual. IGL is set to 12 with 3 split and all idle speeds are set to 0. 1200 revs are the SMALLEST value I can adjust. The TAS is completely screwed out and even when I swrew the AAS complete in, my revs are still over 1100 revs. But I cant understand, why I canīt adjust the AFR in the idle area. I doesnīt matter what I enter, the AFR is still between 11 and 12. When I switch on the defroster, headlights and A/C, revs go dowt to 950 revs.

How can I change the AFR in the idle area?


Chris

arghx

iTrader: (3)

Usually you can't go less that 2.5msec of injector pulsewidth, but it should still run leaner than that on stock injectors. Did you cap off your injector atomization port on the LIM?

Your TPS voltage is within a normal range (throttle cable probably not stuck). Are you sure you don't have a vacuum leak or some other kind of air leak? There's only so many ways for air to enter the engine at idle.

onesus

I replaced all my vaccum hoses 2 years ago. The last days I was looking for vaccum leaks, but I still couldnīt find anything. I checked almost all of the valves, all fine.

Injector atomization port, never heard about this before. I searched the forum for that and found it, i will check it the next days.

When I remove one of the vaccum hoses of the pressure chamber, I can hear the air going out. Iīm not sure, but I think it was more air (louder) some weeks before. I will go on with checking all the vaccum hoses and hope to find something...

onesus

ok, I checked all my vaccum hoses, there are no leaks. The injector atomization hose isnīt capped. But I found, that the PCV-valve is no more good. When I blow into it a little bit stronger, the air flows throught it, from both sides.

Today I tried to adjust manual idle speed. I opened the TAS fully, it doesnīt touch the lever. When I screw it in, the idle speed increases and I want to hold it down.

I opened the AAS 3 turns. Then I turned the headlights and A/C on. Revs are at 760 rpm. I can adjust the AFR with datalogit, it works fine. I adjusted the AFR to 13,5 and the engine runs great!

When I turn the headlights and A/C off, revs go up to 950 rpm. But now itīs not possible to adjust the AFR with datalogit. I can do what I want, the AFR is about 11,8. Why, has someone an idea?

Chris

arghx

iTrader: (3)

Did you do anything to your fast idle system? Is the hose still there on the throttlebody, or did you remove the fast idle cam and thermowax?

onesus

no, itīs all there. Fast idle cam seperates at 60°C.

arghx

iTrader: (3)

post your map from the Datalogit. Are you positive the fast idle cam is fully separated? There is an adjustment screw for it. With the engine warm, when you rotate it with your finger does the idle drop? Try temporarily rotating it completely and tying it there (ziptie or whatever). That will eliminate the fast idle as a potential problem for now. Then you can adjust it later if necessary.

What I've found works best is to get the no load, warm idle set first. Once that is set properly (which may include PFC adjustments) you can work on your cold idle, your E/L, and your A/C idle. Everything is set relative to the basic warm idle. Also, keep in mind that the PFC will engage E/L idle when the fan is triggered on. The "ELD" switch in the datalogit and Commander will tell you whether you are in E/L idle. When you are in E/L idle the timing is advanced. Set your fan temps to at least 95C-100C temporarily (it won't hurt it, remember factory fan temp on stock ECU is 105C). Then you won't have to deal with the car suddenly going into E/L idle when you don't want it to.

onesus

here is the map I used yesterday. P3 in the base-map was set to 1.596 at first. Trying to change the AFR I reduced P3-idle-values but without change.

I will try the adjusting screw for fast idle cam...


Chris

onesus

when I turn the adjusting screw in, nothing happens. By turning the screw out, revs increase up to 1400.

arghx

iTrader: (3)

sounds like your fast idle is ok then, put it back the way it was.
Your ignition timing is pretty far advanced if you want a 750-850 no-load idle. Remember that the factory idle timing is -5L -20T no load with ISC running. This is the same as turning idle IG control off and setting idle speeds in the PFC again.

If you really want to keep manual idle, here's what I would do. Start the engine and let it warm up, keeping all the loads off the engine. Start retarding the leading and trailing ignition. Take a look at the factory ignition timing on a 2nd gen car (stock ports, ISC installed):



I'll say this right now, and not everyone will agree with me--I'm not a fan of manual idle control for all but the most "stripped down" engine setups: no A/C, ISC valve removed, no power steering, basically trackish cars. It's hard to keep consistent idle when extra loads are placed on the system. You are making a lot of compromises.

From my testing the PFC default timing logic, the "hidden map," is simple. With Idle IG control ON, the PFC calculates ignition timing in this basic way:

base idle ignition timing (a separate value for no load, electrical load, or A/C) + closed loop correction value

the base timing is:

-5 L, -20 T for no load idle, same as the FC and FD service manual spec and same as the yellow and red timing marks on the FC crank pulley

4 L, -6 T for electrical load idle. electrical load is triggered by either engaging the fans (fan output) or by the PFC receiving a signal from the electrical load detection computer (ELD input)

I don't know the base A/C ignition timing values off the top of my head. I think it's a little more advanced than the E/L values.

With idle IG control OFF, the values remain fixed to these base values and there is no closed loop adjustment. So with the engine warm you are at -5L and -20T until the fans come on or you switch the headlights or A/C.

ttmott

iTrader: (1)

PIM voltage 2.54 at idle and no fluctuation at all; at least per your attached log file. Should not it be closer to 1.80 - 1.90 at idle?

Possibly bad MAP sensor or check your engine compression.