Is the EEC in the 93 Cobra w/24# injectors different than the 87-93 5.0 w/ 19#ers?

afarkas · 07-30-2002

In my learning journey, I'm having hard times with my new 38# injectors and calibrated Pro-M Bullet MAF.

Several things could be the problem but I'm convinced these are just too big for my current application without buying some chip or special EEC tuner. The car was faster and way more reliable with the 19#'ers so I'm putting them back in for now.

As such, I've heard of very fast Mustangs using 24# injectors and the stock EEC (no chip or tuners). How is this possible? Is the EEC-IV preconfigured to work with both 19 and 24# injectors? If I buy 24# injectors and calibrated MAF, will the EEC-IV be happy?

I really want to make sure I don't run lean (a blower w/ 19# injectors?) but don't want to go down the road of chip's, EEC tuning and bug chasing (yet).

Also, is getting a dyno with an O2 wideband only beneficial for chip burning and EEC tuning?

Vortex · 07-30-2002

Mass air flow sensor upgrade should help the 24's flow better.

86Cobra · 07-31-2002

Yes, the Cobra EEC (X3Z) is different than the GT EEC (A9L, A3M). The Cobra EEC is setup for 24s while the A9L is setup for 19s.

Please don't put the 19s back in. They will not support your level of power. I would skip the 24s and go with 30s. Get your meter recalibrated for the 30s and it'll run fine.

afarkas · 08-01-2002

Thanks for the info.

But I'm confused. If the 93 Cobra uses a different EEC specially for 24# and a 24# calibrated MAF, then how can I stay with my 19# EEC (A9L, A3M) with any other injector regardless of MAF? (24, 30, 36, 38, 42#).

Based on the problems I've had and heard, how can this work without a custom chip with an "O2 wideband dyno" or EECTuner? (p.s. I'm at high altitude).

86Cobra · 08-02-2002

The X3Z is setup for 24s, not the meter. A 93 Cobra meter will work fine with an A9L/A3M and 19s.

To use larger injectors with any EEC, you either need to get a calibrated meter (Pro-M or C&L) for your EEC and injector size or use some kind of tuner (EEC Tuner. TwEECer, custom chip, etc.)

For example, for a while I ran 30s with an X3Z. I used a Pro-M 75mm meter calibrated for an X3Z with 30s. Now I'm running an A3M with the same meter and injectors but I use my EEC-Tuner to make it work. I can go into more detail if you're interested.

afarkas · 08-02-2002

I would LOVE more detail. The Injector, EEC, MAF is throwin me big time!

So, the Cobra EEC is calibrated to the 24's but the stock MAF is the same in both GT and Cobra?

So, the Cobra EEC is 24# calibrated and the GT EEC is 19#?
I've heard that aftermarket MAF's are just tricking the computer to think that 19# is still installed and that (while this works) can cause as many problems as you are trying to fix?

Why do so many people who have big injectors with calibrated MAF still end up burning a chip or getting an EECtuner? It seems for similar reasons that I would have to, that there are always bugs to be worked out (not good for a daily driver).

Anyway, now that I've taken matters into my own hands, I found that Jason (formerly with Procharger, now with Golden West) broke a stock injector, left the O-ring in the manifold, and crammed the 38# on top of it. He also (possibly) stripped both bolts holding the passenger side fuel rail on! So maybe this is why it ran like holy crap after he touched it. I will try the 38's again, installed correctly this time.

This is why I'm going to learn to do most of this stuff myself.

Vortex · 08-02-2002

if the EEC, knows that it is 24 # injectors, than the maf, although its the same size, uses the same amount of air and calibrates it so that it only uses a minimal amount of its spray pattern. aftermarket chips can help give a little more HP, and fine tune all of the options.. not just fuel.

86Cobra · 08-02-2002

Quote:

Originally posted by afarkas
I would LOVE more detail. The Injector, EEC, MAF is throwin me big time!

So, the Cobra EEC is calibrated to the 24's but the stock MAF is the same in both GT and Cobra?

The Cobra meter is larger - it's 70mm. But it's basically "calibrated" the same as the GT meter.

Quote:

Originally posted by afarkas

So, the Cobra EEC is 24# calibrated and the GT EEC is 19#?
I've heard that aftermarket MAF's are just tricking the computer to think that 19# is still installed and that (while this works) can cause as many problems as you are trying to fix?

The EEC gets a voltage from the meter. It looks up this voltage on a table (mass air transfer function) and reads an airflow corresponding to the voltage from the meter. It then pulses the injectors to satisfy this airflow. Aftermarket meters "trick" the EEC by sending it a different voltage. At a given airflow, the aftermarket meter will send a lower voltage reading to the EEC to compensate for the larger injectors. The EEC still thinks it has 19s, sees a lower voltage reading, and pulses the injectors to meet that airflow. But since the injectors are actually larger than 19s, you get more fuel.

This works ok but it's not exact. The ideal solution is to use a chip or add-on tuner to input the new mass air transfer function for the aftermarket meter and the correct injector size into the EEC.

Quote:

Originally posted by afarkas

Anyway, now that I've taken matters into my own hands, I found that Jason (formerly with Procharger, now with Golden West) broke a stock injector, left the O-ring in the manifold, and crammed the 38# on top of it. He also (possibly) stripped both bolts holding the passenger side fuel rail on! So maybe this is why it ran like holy crap after he touched it. I will try the 38's again, installed correctly this time.

This is why I'm going to learn to do most of this stuff myself.

Yep, I hear ya. That's why I do all my own work. Plus it's fun! My buddies help me out but no shop ever gets to touch my car!

afarkas · 08-02-2002

Thanks!

Yes it is fun! Though I'm having trouble balancing my work life, home life, and MUSTANG life. I have no time to sleep (except on the job)!

So, what is the best EEC tuner and the easiest to use? Any web links you can send me to for more info?

See, I bought the 38# ( a little big for my application) becasue I plan on boring, stroking and getting some heads in the near future and didn't want to buy injectors twice. I also don't want to burn a chip every time I smile different at my power curve.

So, 19# injectors are too small (even with FMU wide open I'm told) and want enough fuel and reliability now and after the motor. Any EEC tuning recommendations to allow this combo to work now and into the future?

86Cobra · 08-04-2002

I'm happy with my EEC Tuner.

http://www.eec-tuner.com/

This is a good place to buy it:

http://www.iwantperformance.net/2index.htm

The TwEECer is also a very good product:

http://www.tweecer.com/

If I was buying again, I'd probably get a TwEECer. It's easier to install, comes with better software, and has beeter datalogging support.

Those 38s should actually work fine even w/o a tuner if your meter is calibrated correctly. Obviously you'd be better off with a tuner.

So far the only driveability tuning I've done is to bump my idle to 825 rpm and change my crank fuel pulsewidth so the EEC uses less fuel at startup. I really don't have any issues with my 30s in an NA 306.

afarkas · 08-10-2002

OK, for testing (and against recommendation) I put the 19#'ers back in with the stock MAF.

The car runs great. Since I found TONS of mistakes from the guys who installed the 38#'ers, I will install those again just to be sure.

BUT, I don't think I'm short on fuel running 19#'ers w/ FMU wide open. And even better, my EEC likes 19#'ers very much.

More importantly, Flushing my Radiator and putting in a 180 thermostat, the car runs cool even w/ A/C!!!

So, if it runs cool with the A/C and me romping on it, I don't think it's running lean.

If the 38#'ers stink even when installed correctly, I'm going to sell the meter/injector combo and buy gears or something.

When I actually get a crate motor or rebuild, I'll buy MAF/Injectors and a Tweecer. Thoughts anyone?