Here is one of my latest ideas:

Stage 1: Do a PCM swap with a 85-93 corvette (OBDI), changing sensors where necessary. I understand that tuning an OBDI is a lot easier then OBDII and I have the OBDI PCM available for $15. Basically read data out of stock PCM and write it to the OBDI, and tweak until it operates properly. Might have to replace chip with a blank (I dont have a high intensity UV scanner to erase data).

Stage 2: Change fuel curves (and make fuel curves for boost), ignition timing?, raise fuel red-line cutoff to 7000RPM (or whatever is optimal), adjust speed limiter to 155MPH, and get rid of that GM "shift light". I would use a notebook for data logging and tweaking. I will have to measure changes with a G-tech, I do not have inexpensive access to a dyno, but I do have access to a 1/2 mile private lane/road.

Stage 3: Setup 3 different profiles that would change all the above,like the bullydog diesel kit has. One setting for max millage, one setting for street (EPA legal, 95MPH limiter), one setting for track(155MPH limiter, not EPA friendly). The interface would be a GameBoy Advance. The GBA already has a flash to GBA adaptor and a 64MB flash card. I have a link cable to interface it with whatever I want. From my messing around with it I think I would have 2 input pairs and 2 output pairs. I have written some very simple programs to control a few LEDS.

The victim car is my 04 Eco.cav. It will have (by the time the PCM is ready) custom aluminum intake manifold, header (open header for track setting), WAI , LS1 TB, NX nitrous, motor mounts, close to 250lbs weight reduction (not counting the 50lbs I lost).

This project is going to take a long time, and im not sure its worth the time. I do have the privilege of being able to do this on company time with my coworkers. My department is a bunch of computer science majors, so they pretty much jumped at the opportunity to play around with this.

Is there a better PCM to use? Maybe one that the pins match a little better, or sensors are the same as the Eco?

Has anyone ever attempted this? I saw the gameboy post a few months ago, but this is different.

What kind of power gains could I expect, I am guessing not much from the fuel curves, but some from raising the redline -the eco loves high RPMs as it is now. Supporting boost would be another great thing.

The end goal would be to to boost the cavalier and have a reliable fuel setup with an adjustable fuel curve, knock sensors to cut off boost (like the Porsche 911 turbo), and the ability to keep 35 miles per gallon (if wanted). Let me know if you have any ideas, I am still trying to figure out the gameboy at this point.


My sig....

Neat project, great idea.

1) You will gain little, and possibly lose much, by selecting the wrong ecu for this project. If you're planning to run boost, use a computer friendly to boost to begin with. With a manual transmission, you do not need to worry about transmission controls.

2) You will need to find a solution to drive an instrument cluster and other components. You will want to do some research to see if there's a computer which will control boost and provide the proper signals for the other control modules in the vehicle. By "some research" I mean "a bunch of research." J cars are equipped with several modules which talk to each other, including ABS, BCM, and the airbag. You should find a solution to keeping them happy or a suitable set of substitute parts which do not need to talk to the pcm.

3) The easiest solution to engine control is probably to use the 1227749 ecm from the Syclone/ Typhoon/ turbo Sunbird. Also, the 1227727 ecm from the Turbo Grand Prix would work. The pcm from an OBDII 3800SC may also be an acceptable choice, provided that it can be made to work with only 4 cylinders. An advantage to this pcm is that it uses the MAF method of fueling, and will be much easier to tune to your engine.

4) If you (or anyone in the general public) had the ability to read out the oem calibration info, you would be in a position to modify that same info. And you would be in a position to make changes as needed to work with boost. It's an easier path imo to resign yourself to tuning the engine from scratch if you cannot get oem spark and fuel tables. It's not really as tough as it sounds, and with a little patience you can keep the damage to a bare minimum.

5) Once upon a time there were large gains to be found in factory tuning, but most of that is gone now. The factory does a helluva job on most engines. If you're tuning from scratch, then you'll be making the tune match your engine and probably won't notice any gains unless you do some before and after dyno or track runs.

FWIW, I started my 2.2 OHV turbo project by installing the ecm while the engine was NA. I tuned most of the NA portion of the calibration before the turbo was ever installed. The car is getting 30-ish mpg as long as I can keep my foot off the accelerator, and currently runs 7 psi non-intercooled on 87 octane fuel with a stock 95 spec engine. Sure beats what you can do with an FMU or extra injector! Depending on what happens as the temperature warms up, I may begin tuning the high octane spark tables next.

-->Slow

That could be an huge and amazing proyect, but you would be a hero.
And can be a many Honda users do, from swaping the OBDII ECU to an OBDI one for tuning capabilities.


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ELIOT. Now.....boosted.

^^ they are spoiled and have ready made boosted b18 chips

i wish we could get that sort of thing going. but i doubt anyone will pick it up.



Sven you totally quarterloafed your computer..

If an Ecotec engine appeared at my house, I'd make sure it was installed in my Cavalier for testing and tuning. All proceeds in the for of information and calibrations would be donated to the J-car world.

As Slowolej said the problem is that there are many things controlled by the pcm directly and indirectly--Its the same problem with standalone systems in these newer cars. Untill someone comes along with a solution to the fuel-timing issues large boost and large shots of nitrous are realy just a dream. And i realy dont see it happening if it hasnt yet. Just my 2-cents.

I live in Anderson Indiana. there is a guy here who has about a 90 or so honda civic running an OBDI GM ecm. His dad is one of the local GM computer gurus. Last time i saw it at the track he was runnin high 14s NA. But hondas then still had cable driven speedos and not sure about the air bags and how they work on hondas but oh well just a tid bit of info.

KevinP (Stabby McShankyou) wrote:
and I'm NOT a pedo. everyone knows i've got a wheelchair fetish.

I've been doing some reading about Eco engines with this conversion in mind. There's some cool stuff going on in the engine compartment of the Eco, electronics-wise. How about a camshaft position signal generated by looking at which cylinder is on TDC compression stroke (no cam sensor)! Luckily, that processing happens in the ignition module and is separate of the pcm. But in order to run the Eco with a pcm which does not directly use a CKP signal, it looks likeone would need to feed the CKP signal to an ignition module from a 2000 or 01 Saturn Eco, which would process the signal and generate the standard REF signal that most OBDI ecm's know and love.

-->Slow

slowolej--You sound like you know a little about how these things work. Any idea how to get an MSD DISII unit working with an ecotec? Realy could use the timing retard. One of these OBDI units would be a good pick, but from what i understand this OBDII wont function with any one of its systems disabled?? Like fuel or ignition?? When you start cranking the boost or using larger shots of nitrous realy need a timing retard as well as fuel. ANYBODY ANY IDEAS ON TIMING RETARD??????

isnt that similar to the older quads? they do not run a cam sensor as well. i was wondering if you can just get ignition timing off the crank? wouldnt that simplify things all around. cuz heres what i was thinkin. JBP can alter all kinds of things in the pcm. i was gonna go get a junker 97-98 ecu and have it flashed (GM) for my car, then send it to them so they can take out the cam sensor stuff and alter some other things (redline, timing, fuel) so my HO will run right till finely tuned. that way i can still help with the stuff Shifted is doin and even use it in the end. I was thinking of just running timing off the crank. without the cam sensor the swap should be cake. basically no wiring.

ok on to my real point, to add to the post

what i was thinking is doing a very similar setup and running an eco off it. grab timing from the crank and roll with it. it should make eco swaps easy as pie (minus trans swapping stuff). anyway tell me your thoughts.



Sven you totally quarterloafed your computer..

I fail to see the benefit in this idea, more work than its worth



1989 Turbo Trans Am #82, 2007 Cobalt SS G85

Rodimus, which idea are you talking about? You fail to see the benefit in finding a way to use an engine which should produce 230 hp fairly easily with only boost added? Or you fail to see why someone would want to use that engine without attaching the as-yet untunable electronics? Or you fail to see why someone would want to take the time to understand just how a particular engine management system works in order to modify or improve it? Or maybe I missed it completely.

Jrob, I think we're talking and thinking about two completely different "OBD I" control systems. My thinking is along the lines of using the P4 ecm found in 2nd gen J's to manage the Eco. Sounds like you're looking at using your '95 P6 computer for this job.

For the P4, one would simply toss the Eco ignition module altogether (along with it's cool but useless electronics) and use a 1993 vintage 2.2 ignition module attached to the Eco crank sensor. This would give the correct signals for the P4 ecm and would allow the ignition module to control ignition events during cranking just like the P4 expects.

With just a quick glance, the 95 P6 used with the 2.3 engine looks like it would work fine using the either the 95 2.3 ignition module attached to the Eco crank sensor or the early Saturn ignition module. There's no cam signal needed on our pre-OBDII engines as they use batch fired injection strategy. I'm sure you know that the main reason for the cam sensor is to provide a synch signal for sequential injection. Some cars with sequential injection will default to batch fire if the cam signal is not present during cranking, while other cars will not start at all. Luckily, I believe the J's up to at least '99 default to batch fire mode. The only catch would be whether the timing of the notches in the two cranks are different in relation to #1TDC.

After the trans issues, all that would remain would be tuning. and that's where the fun begins imo.

G Spencer, to create timing retard, you'd need to delay the signals for both coils. The Eco ignition module looks at the coil while it's firing, watching both the polarity and amount of voltage, to determine which piston is on TDC compression stroke. The problem with the MSD is that it completely changes the coil firing signal. I'm betting there's no way for the poor Eco module to figure out where #1TDC is with the MSD attached.

If the Eco engine will start and run with the cam signal disconnected, then you may be able to switch to an ignition module from a 98+ 2200 engine and use that with the MSD box. I'd try connecting power, ground, and the IGN A and B lines from the Eco pcm to the 2200 ignition module, then see if the module tries to fire the coils. If so, then you're probably over the biggest headache. If not... more research is needed.

Another option might be to find a controller which will delay a square wave, then use two of them to delay the coil fire signals to the Eco ignition module. These units used to be available to modify the signal to the old V8 distributors... something called "Nitrous Mastermind" comes to mind. With all the high-tech stuff out there, somebody should be able to find a product that can alter the duration of a couple of square wave signals.

I've found a junkyard selling a 2.2 eco engine for $550... like I need another project around here!! LOL!

-->Slow

slows you rock! ok im sorry.. i forgot to add that i was talking about a 97 2.4 ecu (which i dont need to say is ODB2) on my project.. but either way you more than answered whatever questions i had. Rodimus, which part seems to be too much work? i would think this would be way better than replacing not only the body harness but fuel tank/pump and whatever else is on Suncavi's list of to-do's for an eco swap. i would think a no wiring swap would be very beneficial for swappers. anyway as always slows you are very informative. ill keep you updated on my setup.



Sven you totally quarterloafed your computer..

SLOW, sounds like a plan-But i can't figure out how the eco knows cam position? Looking though shop man and it mentions cam pos sensor but can't find one? there is a wire in the ignition control mod Brn/wht-cam position and goes into Pcm connector C2 pin 26 but cant find sensor? circuit 633?? any ideas? Greg

Greg, you've hit the nail on the head. The Eco doesn't have a cam position sensor.

I dunno what you know about ignition systems, but the Eco has a 2 coil waste spark system. In waste spark systems, 2 spark plugs fire with each coil. Of these 2 spark plugs, one is in a cylinder full of fresh air and fuel and is firing under high pressure from compression. The other is in a cylinder full of exhaust gas, and is firing under much lower pressure due to the exhaust valve being open. On the Eco, the ignition module actually watches the DIS spark plugs fire. By looking at how the power goes through the coils, the module can figure out which of the two cylinders is on compression and is ready to fire the fresh mixture. After 4 revolutions of the crank, each piston has had a chance to come up to TDC of the compression stroke, and the ignition module is ready to generate a signal for the pcm to synch the sequential injection system.

OBDII standards determine the names of some of the signals. I think that's why GM called this signal "cam position," because you can tell where the cam is by which piston is firing. But it would be more correct to call this signal something like "cylinder compression signal."

-->Slow

thanks, yea i understand the basics of the waste spark system. i will have to see if i can come up with a 2.2 ignition mod.
I am sure that the whole thing is possible but no-one is interested in producing any product--They are not even sure which cars there stuff works on. You call MSD and you get wrong info about 50% of the time. I HATE ELECTRICAL!!!! I am a good mechanic-welder-machinist-but electric-NO THANKS.
Back to the ignition, even if the car runs without the cam sig i will bet it goes into LIMP MODE. with the 2.2 ignition! Thanks again for the info.