aGoGo

I am a little down, but here it goes...

Adjusted the TPS and ckecked compression over the weekend. Compression got 3 even pulse with average reading about 100psi. Car was running great and smooth except a exauhst/boost leak. Had a e-fan wire loose last night and car got a little hot only when the turbo timer tries to cool the car down at idle. Found the culprit and fixed that. Had 300 miles in total last night + this morning, again, car runs nice, pulls good with the BNR turbo. Fill up gas with a random bottle of 2 cycle oil (castrol) before I had the 150 mile trip this morning.

Took car out for lunch today, didn't get her warmed up all the way, drove like a grandma, and noticed from the wideband that the car was running super rich and almost dying out at idle, afr fall below 11. Got home, searched on the forum, reset the SAFC, took her out for a test, runs ok, not as smooth. Stop by a gas station, then the car dies at idle, and couldn't get started as if there was no fuel... Heard the fuel pump when cranking ....

Waited abit, played with the SAFC settings ... waited ... then the car started, heading back home, then it run rich again on my way back, same symptom ... hurried up and got home.

Now I just couldn't figure out where could possibly wrong. The car is a GXL/TII conversion, got 720 pri and 890 sec, SAFC, Rtek1.7 ... I am sensing a sensor could got bad, but have no clue .... this is my first FC and just got it last week ... Please help me out, any input would be appreciated!!!

-X

Icemark

TPS is probably adjusted wrong. Did you adjust it with a warm engine???

HAILERS

A RX with a stock ECU runs a full AFR richer when cold vs hot. Such as when the water temp is below 120 degrees you might see 12 afr and when above 120 it goes right up to 13.0 afr. Just FYI.

aGoGo

I adjusted the TPS when the car is cold .... should I do that when car is warm? All emission stuff is gone, I haven't seen any warm up procedure where the engine goes 3K at start up with this car, not sure even about the compensation from water temp.

The car was running fine, but all of a sudden .... The boost leak is getting worst too. I will do another compression check today, hope the motor is ok, since the Wideband is sensed from the exhaust, could that be the motor is going south? I did premix wrong? (too much too little? Bad oil?)

Should I try to clean my MAP sensor? Any other things I can look into? I remember calculating to set the base at idle to -23% since the primaries are 720. Is the AFR reading accurate with a exhaust leak?

Thanks -X

Icemark

yes TPS must be adjusted warm. It will change pretty radically as the sensor warms up.

See that is the reason for the fast idle start up and thermowax cold idle assit as well. It makes the ECU ignore the TPS by holding the throttle open slightly. This bypasses the off location of the TPS until the car and TPS is warm.

aGoGo

Ok, I will ckeck the TPS, thanks Icemark. I just played around a little bit, the car started fine, but soon after a minutes or so, it just get rich and fall flat on the AFR. Took her out for a spin, feels a little out of tuned (slight hesitation + uneveness through the RPM is all over the place), runs rich in general, and idle is flat rich.

I don't know what got changed between yesturday morning and noon (please refer to the first post), except I browsed on the SAFC a little...

The vaccum stays at 10 inHg at 700 rpm about 12 - 13 around 1000. There is a valve held open with a zip tie just below the TPS, I don't know what that is, gussing that's cold start compensation stuff. Last night when the car died at idle in the parking lot, the SAFC somehow changed its setting, particularly it changed to 6 Cyl Arrow Right UP, maybe that was the problem. But I set it at 4 Right Up all time... used a bottle of starting fluid, and found nothing.

Anyways, here is the current setting about fuel, I will change injectors, but hoping it would run fine right now.

720 pri 890 sec
Walbro 255 + stock FPR

I assume the previous owner setup the SAFC to the MAP (???) since it is a S4 with short TPS, and the pressure reading on the SAFC stays at 760 mmHg at all, nevertheless, here is the reading/setting ...

Sensor check:
In1: 4.005 V
In2: 0.08V
In3: 2.26V

Low Thr Pnt:
1000 -24%
2000 -16%
3000 -12%
4000 -7%
5000 - 2%
6000 0%

Hi Thr Pnt:
6000 0%
7000 +7%
8000 + 14%

Thr Pnt (<= this don't make sense to me)
Lo: 81%
Hi: 99%

FC wizards, Please advise

-X

HAILERS

*******In1: 4.005 V
In2: 0.08V
In3: 2.26V***************

Is that with the engine idling? Or key ON engine OFF?

In1 should be afm

In3 looks like boost sensor.

So, your free online FSM says in the FUEL section that with a hot engine, and at idle, the AFM should read b/t 2-3VDC at idle.

It says the boost sensor voltage , with the vacuum line to the sensor pulled off and capped, should read 2.3 to 2.7vdc at idle.

The SAFC should read 4cyl, arrow up and to the right, 05 and 05 and FLAP. Check it out.

I don't mess with SAFC anymore on the turbo cars, BUT when I had it on there, and connected to the boost sensor, I set the high by looking at the *TPS* (now really the boost sensor) with one eye and had the other eye on the boost gauge (aftermarket). When I went from *negative boost* to just boosting, I eyeballed the TPS percentage. That figure was what determined the HIGH Throttle Point. I THINk it was in the 56% range. So 56% was the HIGH throttle point.

It seems your In1 and In4 were with the engine off and key ON. They look normal. The 2.26 you show will rise a touch if you had the engine idling and the vacuum line capped off. Nothing really wrong there.

You might drive and watch In3 and make sure it varies with rpm/throttle input.

aGoGo

Thanks Icemark, I re-adjusted to TPS when the car is warm, and made some improvements to keep the screw tighter.

Thanks HAILERS. You are right on with every comment you made!!!

After I got your message, I spent past 2 hours trying to play with the SAFC, test run ... SAFC ... test .... It runs a lot better now, but I would need some better ideas in general about how to compensate and how to tune. I would like to have a clear understanding about how our car behave, right not I am just doing trial and error without much rationale. It idles about 13 (AFR) now, and some how, as soon as the efan kicks in, the AFR drops to 12, I am sure it would affect AFR for all RPM ranges when there is a electrical draw. The car got a Crane 6 (something) .....

I understand what Hi Thr Pnt means now, but what about Lo? What does that mean? I set it to 10%, which is the same a default.

Here is the current setting

Hi Thr Pnt: 56% ( I just took your number for now, my gadges are far from SAFC)
Lo Thr Pnt: 10%

Hi Thr from 1000 rpm to 8000 (percent): -14 -11 -7 -4 -1 +1 +5 +12

Lo Thr from 1000 rpm to 8000 (percent): -24 -17 -12 -6 -2 +1 +3 +5

This setting might look funny in the eyes of experts, but I have learnt a lot about our cars in merely a week!!! I am happy about that. It is getting there, I will do some improvements everyday.

BTW, is there a good way of checking where the exhaust leak is coming from?

You said if I cap off a vaccum line the 2.26 reading would rise, which vaccum line are we talking about here?

Thanks so much!!!

aGoGo

What is "Free online FSM" BTW?

Icemark

FSM= Factory Service Manual

HAILERS

You know that the HIgh effects the Low and vice versa? Say at 5000 rpm you have the High a -15 and the Low at 5000 rpm is a -5. So if your driving along at full throttle, on the CORRECTIONS screen you won't see a -15 but something b/t a -15 and a -5. Like the manual say, it interpolates b/t high and low.

13afr is a common figure at idle, at least for my cars it is. Idles smoother there than 14afr.

Low will be in effect from 10 thru 56. High 56 and up.

Use your variable resistor to effect the idle mixture if you have a 86-88 series four car.

I knoiw next to nothing about tuning.

OH. About the that boost sensor vacuum line. The FSM gives you the input/output of each wire on the ECU. At idle, it says the boost sensor should put out the figure I gave you earlier. It should be in that range. The boost sensor is on the front side of the right front strut tower. It has an electrical plug and on the bottom a vacuum line. They say you should pull the vacuum line off and plug the LINE with a screw/whatever. Then start the engine and read the voltage for the Boost sensor.

In other words the boost sensor will be looking just at atmospheric pressure and not be influenced by the vacuum off the engine. When done, be SURE to reconnect the vacuum line to the sensor. A must thing to do.

You might get a touch higher reading for the boost sensor output if at idle. I find just having the key to ON gives almost the same reading as if the engine is at idle. Just fyi.

aGoGo

Ok, HAILERS, I will check on that. Somehow ... the AFR readings with my setting last night is readlly difference from this morning, the idle goes rich again, and the AFR drop due to the efan is kinda a concern. When I was in the parking lot this morning idling, it started to lean out again like what happened at the gas station, I tapped on throttle it came back up and then back and forth, and I turned the car off.

To summarize,

1) Why when efan kick in the AFR drops? Do I need to correct any flaw?
2) AFR readings don't stay the same with same settings over time
3) Actually, what is the good AFR ranges for the car to operate at?
4) Any thoughts on the lean/kill act in both parking lots?

THANKS!

-X

HAILERS

Not really. Like I said before, I think.....when the engine water is cold, the afr will be richer, such as 12afr. Once the temp gets above approx 120 degrees the afr will go leaner by approx 1afr to 13.0. That is just and example.

Low throttle and just tooling around the block with a hot engine the afr are in the upper 14 to 15 at steady throttle. Step on the pedal and it'll go to the 12's or if just a bit lighter throttel maybe the mid 13's. Depends on LOAD.

Wide open throttle up a hill under load I run mid 12's all the way up to redline. I have just a run of the mill stock car with a little bigger exaust than stock and no catalytic converter.

The afr's at idle are right at 13 give or take .3 or so. I can idle at leaner but then you get that little poof, poof once in a while that I don't want.

I suspect the E-FAN is being seen by the ECU as a load and is adjusting the mixture. Pull the plug off the E-FAN the next time it does that and watch the afr's for a change one way or the other. Do all the above with a hot engin or at least above 120 degrees.

And next time the engine is HOT, adjust that TPS to an output of approx 1vdc. Series four, right?

OH. And when the ECU sees the load of the EFAN, it inputs to the bac which tries to keep a steady idle thru a higher duty cycle.

When HOT how high/low is your idle speed. Give a figure.

aGoGo

Got it!! The efan is hooked up to a harness by the head light, and it might be seen by the ECU, what about the alternator then, it also has load when the efan is on, is that still an issue? The S6 Alternator gets really hot and the tension caused by the resistance makes the belt screaky. I was thinking about rewiring and isolating the circuit straight to the battery, since currently the efan would be off with the key off, with a dedicated circuit, it would run off temp switch (I need to figure our how that's powered too).

I adjusted the TPS via resistance when engine was hot, it is at 1k. It surely idles alot better than I first got the car. I assume there isn't a BAC anymore since all the emission stuff is taken off (need more learning). Well, little bit everyday, we will see how it goes in a month.

Thanks SO MUCH !!!!

aGoGo

Well.... I search under the hood, but could find a idle mixure resistor!!! Is that possible the part did not get put back when the car was converted? Can it run like that?

Yes the efan is definitly dropping the AFR by one full bar when kicks in!!! Wire directly from the battery then?

aGoGo

This is how it looks like under the hood. Please spot anything you can!

Also there is a metal screaking sound from the front of the engine, what could be the problem?

Thanks

HAILERS

If the harness in the engin ebay is out of a series five, it won't have a variable resistor. The variable resistor on a series four is located near the boost sensors plug. How near? I'd guess a foot or so. No time to look now. It has a round plug it connects to and has but three sockets/pins in the plug.

No matter where the power comes from, when the efan comes on the ECU is going to *see* the load (if the key is On).

aGoGo

Hmmmm .... the RPM and particularly the AFR is not consistent, and there also (feels like) a little delay between fuel and air, the throttle is very touchy.

My favorit part of the rotay is the smoothness over a wide RPM range, which leads to a "alive feeling" ... So there isn't not much I can do regarding to the efan? I really want things to happen in a predictable manner.

I think you all have helped me to ion out the bug I had initially, and I think it was simply flooded due to poor tuning .. this happened one more time, I was able to use the deflood feature of the Rtek and had it started in a crank. Oh, when the car is hot, it starts within one crank of duration ... a little hairy here, but hey, it starts ... There are other improvement on the car's behavior and handling I would want to get to. Perhaps I will start another thread addressing these issues.

I believe the harness is from a S4, that's what I was told, but as you can see from the picture, I can not locate a Idle Mixture Pot.

What other things looks different from a stock S4 Tii?

Regards

HAILERS

Metal screeching sound. From the front...................possibly the front pulley was pulled off at some time and when reinstalled the torrington bearings fell out of place? Got me. See MAZDATRIX.COM (http://www.mazdatrix.com/faq/pulley.htm) and their FAQ and their jpgs of what happens when a torrington bearing falls out of place.

Or you could remove the alt belt and start the car up and listen, just for a minute or so. Sound still there? Isn't the alternator then, not the water pump so must be internal to the engine. See the first paragraph if so.

HAILERS

Looking at your jpg, I can see part of the Solenoid Resistor package, which in turn means that EM harness had a Variable Resistor on it at one time.

IF you measure 12 inches from the solenoid resistors plug, up the harness, you find the harness branches out into three branches. The Variable Resistor plug is six inches from that branching out of the harness.

aGoGo

Thanks HAILERS and Icemark for your help. The car is improving everyday. I think it might be a good time for put an end to this thread and start fresh and specific topics.

I did not have much time to search for the idle mixture resistor, but that's in my plan for the weekend. The screeching noise should from the Alternator, it gets louder as the current load increases. I will leave it there for now, and possibly re-tension the belt.

Thanks again!!!