Basic TwEECer tuning questions.

[Fett]

I am thinking of buying a friends twEECer, but am not sure if it will do two things. I know you can buy a DataQ so you can run a wide band O2 sensor....but can the tweecer read a/f with the stock o2s? In other words, if I use a tweecer, can I see my a/f with just the tweecer, my stock PCM, and the stock O2s?

Also, if I am having a MAFS problem....basically because ProM MAFS suck and have basic perameters, can I fine tune a ProM MAFS or can I use another known-good MAFS and just install my own settings?

I am trying to figure out if even going with a tweecer is worth it or not. I know I can remove my EGR and thermactor functions from the PCM with a tweecer...I just don't know if it will help getting my a/f right and my tune right, without adding a wide band o2.

 

[stang&2Birds]

You're running 24's and an "E" cam & 1.7 rockers. Your ProM is the LEAST of your worries!

You can get an "idea" of the OVERALL A/F over MANY SECONDS. The stock O2's just switch between rich/lean. It's how much time it spends in the rich area, that gives a ROUGH idea of the A/F.

Do you have your ProM flow sheet? If not, you'll HAVE to custom tune your flow numbers by hand. Do you have the stupid engine bay cone filter? If so, you're SCREWED. You have "some" chance that it "might" work well enough so that you engine doesn't end up in pieces on the ground. Get rid of the stupid engine bay cone filter. Put the filter in the fender (or a box that connects to the fender) where it belongs and block off the fender to engine-bay openings so you don't get that 300+F heat into the fender.

Get the tweecer. Fix your injector size, and your MAF curve.

BTW: For $90, you can get a 90mm FORD OEM LMAF!! It's more accurate, ~4% from baseline vs the ~9% for ProM (Orig ProM MAFs, not the PMAS new style MAFs).

Trying to get your A/F correct without a wide-band is HARD to do. IMHO, near impossible unless you get lucky or spend hundreds of hours screwing around. Many people try the get lucky approach first. But, since you can read the main trim table, it's risky.

Regardless, it'll be better than the setup you have now. Plus, you can bump the idle speed up in the ECM. That will help initially if you have stalling problems now.

Oh, is a a TWEECER RT??????? If not, you can only data log through the DataQ. IMHO, today, I wouldn't bother with a regular Tweecer.

Last: If you have a QTR MILE ONLY CAR, and you have a **COOL** engine bay, then a cone filter is "okay" as long as you have it WELL blocked from fan wash. IMHO, I haven't seen a fan wash block in a Fox that wasn't a semi-joke.

 

[vristang]

^^^^well said


If it is an RT jump on it, assuming the price is right.

You can do some great tuning at part throttle and idle without a wb O2, but to make any changes in wot you will want to use a wb.
It would be better to use a wb for idle/part throttle as well though.

You can use an LC-1 from Innovate to datalog the wb via the egr wiring.
The LC-1 is about 200.
http://www.diyautotune.com/catalog/innovate-digital-wideband-controller-with-sensor-p-41.html


The LMAF (90mm) mentioned by Joe can be found for 80.
http://www.buyfordracing.com/shop/product_info.php?products_id=504



Let us know how it goes!

jason

 

[stang&2Birds]

BTW: Vristang has a good intro to the Tweecer on his website.
START THERE!
http://www.freewebs.com/vristang/a9tweecerguide.htm

Initially, do *not* get too bogged down in the ability to do a few hundred things. People see ALL of the stuff a Tweecer can do and they give up.

You can get a GOOD tune by doing the basics! Before the RT, that's what we had to do. I started on the EEC-tuner.

For an intro in the the EEC-IV system, TMOSS did a *great* write up. Again, do NOT freak out about having to "know everything"! Read it. Understand the basic ideas. Play with the Tweecer. Read the document again. Read Probst. Read other stuff, and so on. You are NOT going after a job being the ace tuner at Ford SVT!

A Quick Overview of the Inner Workings of the EEC (Mustang Fuel Injection Computer), by TMoss:
HTML/web version: http://www.veryuseful.com/mustang/tech/engine/EECIVInnerWorkings/
PDF version: http://www.veryuseful.com/mustang/tech/engine/EECIVInnerWorkings.pdf

Good Luck!

 

[Fett]

Ok, so an 03 Lightning MAFS will plug right into my 91 harness?

Also, I have my air filter in my fender, all sealed away from the engine temps.

It is an R/T, so I can data log.

 

[Fett]

You're running 24's and an "E" cam & 1.7 rockers. Your ProM is the LEAST of your worries!

What do you mean?

 

[projectfiveo]

I am thinking of buying a friends twEECer, but am not sure if it will do two things. I know you can buy a DataQ so you can run a wide band O2 sensor....but can the tweecer read a/f with the stock o2s? In other words, if I use a tweecer, can I see my a/f with just the tweecer, my stock PCM, and the stock O2s?
.

how can i use this if i dont have any 02's???

 

[vristang]

how can i use this if i dont have any 02's???

You do still have the stock O2's right?

The tweecer RT will datalog and display some info from the factory O2's.
It just isn't as accurate as what you want when making changes to your tune.

This is why wideband O2's are so beneficial. They are much more accurate.

The tweecer will still function with stock O2's, it just won't be as accurate.

jason

 

[vristang]

Ok, so an 03 Lightning MAFS will plug right into my 91 harness?

Also, I have my air filter in my fender, all sealed away from the engine temps.

It is an R/T, so I can data log.

There are some changes that will need to be made to run the LMAF.

The plug harness is different, but the correct one can be ordered, or found in a yard. There are adapter kits available I believe, so that you don't have to splice and solder.

Also the LMAF uses a bolted flange to connect to the air filter housing. You can see the four bolt locations in the pic, if you follow the link I provided above. Again there are adapters available in the aftermarket for this.


I have always thought the main reason for keeping the air filter out of the engine bay was to avoid the turbelence which results from fan wash.
The air kicked around by the radiator fan has been blamed for causing some idle control issues.
Personally, I still question the power benefit of 'cold' air. But that is just me.

I wish you luck with the tuning.
It is a fun experience, and you will learn a lot in the first few weeks.

jason

 

[Fett]

The fan wash issue makes sense, I always put the filter element itself in the fender was to keep it sucking cool air.....as cool as possible anyway.

I see what you are saying about the LMAFS, basically cut and splice the correct connector and use the Tweecer to load the LMAFSs table (flow chart) so the it will work with the 24lb injectors. From what I have been reading, Pro-M MAFS suck...they have a general table and don't work accuratly with 24lb injectors.....even if the Pro-M is calibrated for 24lb injectors, which mine is.

I am still stuck on why I have bigger problems with the e-cam and 1.7 rockers.

 

[vristang]

Joe (stang&2birds) sometimes doesn't check back on old threads.

I will take a stab at what I have heard the problem is.

For whatever reason the E cam seems to casue some pretty serious idle issues.

This is what I have gathered in reading idle threads and whatnot.
No personal experience, and I can't explain why the E cam would cause this.

Maybe someone else can chime in with some reason?


jason

 

[Fett]

Oh yea, at first the e-cam was causing a lot of surges. I let the engine get normal op temp, unplugged my IAC, adjusted my throttle to 900rpms, replugged in my IAC, then adjusted my TPS to .97. Now the car idles perfectly. No more surging, no more hunting for idle. Even when my e-fan comes on, it doesn't cause any idle issues....like it did before my adjustements.

Which is one of the reasons I posted in the thread about adjusting the TPS. After adjusting my idle, it would still surge slightly, especially when the fan came on. But since I adjusted my TPS, the car runs and idles perfectly.

I am just deciding, at this point, if I would really benefit from a tweecer. Removing the EGR, thermactor, and getting my a/f right.....along with entering a good MAFS table so it will hopefully keep my car from running lean/rich.

 

[vristang]

Oh yea, at first the e-cam was causing a lot of surges. I let the engine get normal op temp, unplugged my IAC, adjusted my throttle to 900rpms, replugged in my IAC, then adjusted my TPS to .97. Now the car idles perfectly. No more surging, no more hunting for idle. Even when my e-fan comes on, it doesn't cause any idle issues....like it did before my adjustements.

Which is one of the reasons I posted in the thread about adjusting the TPS. After adjusting my idle, it would still surge slightly, especially when the fan came on. But since I adjusted my TPS, the car runs and idles perfectly.

I am just deciding, at this point, if I would really benefit from a tweecer. Removing the EGR, thermactor, and getting my a/f right.....along with entering a good MAFS table so it will hopefully keep my car from running lean/rich.

It sounds to me like bumping the idle speed up higher may be what actually smoothed out the idle. But who knows

The idle getting worse due to the fan coming on could be 2 things, that I can think of now. Either fan wash, which you shouldn't have, OR, there is a setting in the EEC called Injector vs Battery Offset (aka vBat).
You will have access to the vBat settings with the tweecer.

Basically, the injector pulsewidths can vary due to supplied voltages. More voltage will result in more pw and vice versa.
Aftermarket injectors will react to voltage drops at idle differently than the stock innjectors.
The fan pulls quite a bit of power, so you will see a slight drop in voltage when the fan comes on.
Personally, I saw some good idle quality improvements when I started getting into the vBat's.


In my opinion it is worth it to get a personal tuner, if you have the patience to learn how to use it.

jason