I have become fascinated by the "mystery" of making a custom chip for my Fiero GT (Turbo).
Does anyone know how you go about learning about this and where and how much the equipment is to get started.
I will be glad to experiment on a custom chip for your car until I get it right. Ed

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http://www.thirdgen.org/newdesign/tech/promintro.shtml

Pretty much the same procedure. I'd recommend changing the stock chip (EPROM) over to a flash chip, and using a ZIF socket. (put a regular 24-pin socket in the ECM, a 24-to-28 pin adapter, and then plug a ZIF socket in to that). You'll need a 24-to-28 adapter from someone like Craig Moates at http://www.moates.net

(can't find my ZIF socket right now, but that's an '86 Fiero ECM, socketed, with a 24-to-28 adapter on top)

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85 GT 2.8/Auto (daily driver)
2 x 86SE 2.8/Auto (parts cars)
79Z28 / 94Z28 / 98Z28 / 93 Suburban
1 wife who thinks I'm nuts...

There is a LOT of good information available on early generation PROM burning at www.ThirdGen.org. Look in the Forums, under DIY PROM. The processes are much the same for most GM OBD systems, and the equipment is the same. You can get a PP2 burner, an ALDL serial cable, and the freeware you need to analyze and program for about $200. You'll never go back to stock or off-the-shelf PROMs again.

I don't know your expertise level when it comes to building and tuning engines and thus don't take offense; but if it's not very strong, do indeed learn a whole lot before you venture into that area. You don't have to burn many parmitors wrong to distroy an engine in short order. Also, if you want to do it anywhere near right, you'll need to get yourself a wideband or least take the car to someone that has one after you put your new chip in. I know some folks will say you don't need the wideband and if you don't change anything that will affect the A/F ratio you probably don't, but then why burn a chip? I'm NOT saying this because we want to sell chips, we DON'T. We only do them for our intake customers. Burning chips for folks is real PIN. You burn a chip, it works great, and then they change something major on the engine and then they want to know why the chip suddenly is NG. If you want to do them, learn what each paramitor will do first. Good luck.

I disagree, Francis T. I say go for it! You'll never learn if you chicken out. If you search the 'net, you'll find everything you need. It is out there. It's how I got started 8 years ago (and there wasn't nearly as much info out there back then). We all know nothing at some point... As long as you take a logical approach, and 'creep up' on the tune (not doing crazy stuff - most people don't/won't!), you'll be fine. Read, read, read.

I was tuning my cars well before I "built my own engine". But I've done that too, now. The LS1 I built put 487 hp to the ground...

You've got to be careful. You can make your car undriveable, or worse yet, damage something.

Having said that... Work slowly. Baby steps.
Buy a bunch of chips. Make small changes, one at a time. Make sure you identify what changes you made. Always keep a 'baseline' chip, so that if you do something really wrong, you'll still have something that will let your car run, etc., etc., etc...
Baby steps.

Buy and read Motorbooks "How To Tune And Modify Chevrolet Fuel Injection" Cat.# 124678.
It doesn't tell you how to burn chips, but it's an excellent primer regarding how EFI works, and it does cover systems like ours. Well worth the $20 or so.

For the nuts and bolts...
You'll need a scan tool so that you can see what your engine is doing.
If you have a laptop, WinALDL is free, and downloadable on the net. Several people here build the cables required to interface your car to the laptop.
Otherwise, you'll need an OBD-1 scantool and a GM cable.

Here's some links for programming hardware and software...

http://www.tunercat.com/ Prom editing software. There are others, but I believe that this one is the most widely used.

http://www.xtronics.com/memory/index.htm Check out the Pocket Programmer 2. It comes with the software that you'll need to make your computer talk to the programmer. This is NOT to be confused with the editing software that Tunercat sells. You'll need them both, as well as the default files for your particular ECM, which Tunercat also has.
You'll also need the UV eraser, unless you decide to go with EEPROM chips. I can't help you there, as I'm still using the UV eraseable chips. The 'moates' link, above, has info if you want to go in the other direction, as well as some nice extras like ZIF sockets, as already mentioned.
The UV chips (which is what you have now) are 2732s or variations (2732A, 27C32, etc., etc.) Be sure to read about the differences, as they all use different programming voltages. You can burn out the chips if you use the wrong voltage for programming.

Check out the links that AKM posted above. Good stuff.

Did I mention to be careful? I've had my equipment for several months and I'm about to finish with some driveability issues that I had (TCC lockup points, decel fuel cutoff, cold engine stumble, etc., etc.) These were all light-load, part throttle parameters that were affected by the particular combination of pieces that went into my engine. I haven't even tried any 'go faster' tweaks, as that was never an issue.

[This message has been edited by Raydar (edited 09-29-2005).]

I agree with all post here and all of them very true. Anyone can fly a plane but you need to get educated first to avoid crashing. Burning PROMs is the same thing. Get well educated first and be safe and you won't crash. Go for it

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Palm Beach Fieros
http://pbfieros.tripod.com

I never told him not to go for it. I simply told him to learn as much as he can first. One other note; while sometimes you have to change 2 paramitors to get to where you want to be, try not to change them all once, else you may drive yourself nuts trying to figure out which one is screwing things up. The two bigies to be extra careful with are ign timing and your injector duty cycles as you don't want a lean A/F ratio. Raydar's advice about keeping a baseline or standard chip is an apsolute must.

Excellent topic firefighter, I've bookmarked this one as I am looking for someone who can burn a chip for me. Looking for a chip without the "stall saver" and a lower temperature for a cold idle kick down on my 86 V-6, four speed.

Eliminate the 'stall saver' feature of the PROM? Uh, not good. Do mean the deceleration enleanment fuel cutoff?

quote Originally posted by Cooter: Eliminate the 'stall saver' feature of the PROM? Uh, not good. Do mean the deceleration enleanment fuel cutoff?

Jetman doesn't want the ECM to float the RPM between shifts and until the VSS goes to zero. It's not in my editor. I guess I could add it...

[This message has been edited by TK (edited 09-30-2005).]

Rather than eliminate the stall prevention... You might be better to adjust the RPM steps and time delays involved so it flattens faster/smoother. The complaint I usually hear about this is it takes too long to drop at stop lights.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurasic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

quote Originally posted by TK: Jetman doesn't want the ECM to float the RPM between shifts and until the VSS goes to zero. It's not in my editor. I guess I could add it...

Ahhhhhh, makes sense now. I never thought of that as being a problem, but what the hell- fix us up Terry.

quote Originally posted by TK: Jetman doesn't want the ECM to float the RPM between shifts and until the VSS goes to zero. It's not in my editor. I guess I could add it...

It doesn't appear that Tunercat has it, unless I just don't understand the parameters that I'm reading.

Cooter, check your email.

TK

ooops, wrong thread.

[This message has been edited by TK (edited 10-18-2005).]