Moates tuning a 94 GT

Buicknick72 · Feb 26, 2013

Took the Mustang out of hibernation, it's been sitting for 2 years. Time to get a tune on it.

The engine is rebuilt 306, E303 cam, ported stock heads with 1.9/1.6 valves, Trick flow intake, 70mm tb, stock MAF, R/R's. Stock 19# injectors(will upgrade when I have the time). All factory emissions equipment. Stock comp ratio. 5 speed. It runs solid, but I had to do the usual tricks to get it to idle well. Goal was solid street car engine.

I have the F3 moates chip with the stuff to program it. I have a lot of other stuff going on, so I can't put any more funds into it at the moment. I know the Quaterhorse is amazing, but can't happen at the moment.

This is my planned approach for tuning it (using CalEdit since it's free, yes I know BE is better...) I don't need to get crazy, and don't have time to fiddle much with it, just need a tune that will work better than stock and idle right.

Start with a Cobra tune-

Change engine size to 306.
Set injectors to 19#
Eliminate all Tip in retard junk.
Make timing advance kick in a bit sooner, anyone have recommendations?
Set idle to 900rpm.

What else should I change while I'm in there? (I don't want to eliminate any emissions equipment.)

Thanks

rz5.0 · Feb 26, 2013

You have nothing on there that should make it idle bad except for the TB. With your mods the stock unit would of been fine.. You can lower your fan temps a lil..

Buicknick72 · Feb 26, 2013

I did just find something that wasn't quite right, and was probably bad when I was driving the car years ago. So I may have better luck setting the idle. I never had much time to devote to the car. I was able to get it to idle smooth before, but had to open the air screw to get it to about 900rpm, but it ends up higher while coming to a stop(clutch in), and once stopped drops to the 900, just kinda annoying.

The stock TB was running out of steam, so I put the bigger one on and gained top end pull.

rz5.0 · Feb 26, 2013

Have you been on eectuning.org yet? I don't know cal edit was compatible with moates since it used for the tweecer..
I can prob email a base tune that i used to get started. But its a .beb file.

RichV · Feb 26, 2013

Buicknick72 said:
I did just find something that wasn't quite right, and was probably bad when I was driving the car years ago. So I may have better luck setting the idle. I never had much time to devote to the car. I was able to get it to idle smooth before, but had to open the air screw to get it to about 900rpm, but it ends up higher while coming to a stop(clutch in), and once stopped drops to the 900, just kinda annoying.

The stock TB was running out of steam, so I put the bigger one on and gained top end pull.

Mine does this too, the higher RPM while coming to a stop, then normal. What does this?

I don't beleive it's in the tuning, I run a Fox ECU. Did it with the T4M0 too.

rz5.0 · Feb 26, 2013

Usually vac leak but if its not.. I bet its cus of your TB.. You could prob fix it with dashpot but im not an expert..

Buicknick72 · Feb 27, 2013

The ECU has something in it that will bump up the idle speed while the car is moving. It may be for smoother shifts, or to make sure the engine doesn't stall/or pop on decelleration maybe... whatever the reason is, in normal operation you barely notice it. You'd slow to a stop with the clutch in and it would idle at 850-900 rpm (not sure exact numbers), and then drop to the 650-700rpm (whatever the idle set point is) when you come to a complete stop. The small amount is never really noticed. But it gets exaggerated when things are not right. A vacuum leak will do it. In the case of my 99 Ranger- the previous owner used a harsh chemical to clean the throttle body and it removed the inside coating, in turn causing it to pass more air at idle, so the base idle was too high, around 1000rpm, but when I slowed down it was at about 1500-2000 RPM. When I came to a complete stop it would drop to the 1000rpm. Very annoying. My solution to that was to plug the drilled hole in the butterfly, and use the stop screw on the throttle to get idle where I wanted it, and it's been happy ever since.

In the case of my Mustang, I had a dead spark plug I never knew about, so I was down a cylinder. Since I never had time to spend on the car, and searching 'E303 idle' you find a lot of people have idle issues- I just figured it was normal and I compensated for it by getting the idle at about 900rpm with the air bypass screw. The ill effect in my situation is that when you let off the gas to make a shift, the RPM's don't come down fast, and the slowing to a stop idles at about 1500rpm.

When I just re-registed the car last week, I changed the plugs/wires and found the bad plug, which would have caused my original idle issues. I re-did the idle setting procedure and now it works good, enough rough idle that you know it's got a cam, but not stalling out, somewhere around 750rpm.

rz5.0 · Feb 27, 2013

Glad you got it sorted out..

Buicknick72 · Mar 15, 2013

Failed emissions horribly. Checked the codes, one bad o2 and the EGR circuit not working. Replaced both o2 sensors, both original ford pieces with over 100k on them- yikes! Electrical plug on the EGR vac soloniod was unplugged under the fender?!? must have been like that since before I owned the car, it had some body work done. Checked my BBK air filter, super dirty. My brand new BBK FPR was leaking vacuum?!? put the original ford piece back in. Pulled my MAF sensor, the filter side of the sensors were black with dirt buildup. Cleaned that.
I'm super busy so I still need to get in all back together, hopefully this weekend. It pulled pretty hard with all these issues, so I'm excited to see what it does with everything straight.
I didn't realize how much I neglected this car when I used to drive it. Never had time to spend on it.