Ecotec Swap Questions (LE5 Engine Management) (Page 1/3)
zkhennings MAR 09, 01:50 PM
After a long hiatus I am finally going to be swapping an Ecotec motor into my Fiero. History of my car here

Since storing the Fiero, I have done much work on my 02 WRX, and put ~120,000 miles on it, it now sits at 249,000 miles, everything in it has been replaced/upgraded at this point (except the trans), but the motor (170,000 miles) is getting tired and the trans is getting noisy, I need to shim the trans and rebuild the motor and turbo, maybe run new brake lines too as I intend to delete the ABS, the ABS is awful in that car when going over bumpy or slick surfaces. Also needs a few areas of rust repaired. Seems like the perfect time to get the Fiero driving again for the summer to do some work to the WRX and have it ready for next winter.

I have debated for a while what I want as far as Ecotecs go, but I think I have settled on an LE5 mated to an F23 (M86) 5 speed transmission. I plan to leave it NA for a while, and make some headers for the motor to get a little more power. Looking for close to 200whp which seems very reasonable when researching Miatas with LE5 swaps. My car is very light, it has 0 options, no power anything, no AC, no cruise, and I have stripped any extra bits to make it as simple as possible. ~200hp would be very fun, and the balance of the car would be great for the twisty roads we have here in the North East. It was really fun with the 132whp 2.8 I built for it, but the rear end felt really heavy. It also was inconvenient to work on the 2.8 when compared to the tiny Ecotec in the Fiero's engine bay.

I looked at the L61 2.2 Ecotec for a while, but the price between LE5 and L61 is nearly the same now, and it appears to be a superior motor. I considered the LSJ as well, but I would rather experiment with some forced induction on my own on a 400$ motor. I considered the F35 trans with LSD (~$1000) but it is pretty pricey compared to the $150 F23. I can put a Quaife LSD into the F23 down the road, and if I blow the F23 I can swap the Quaife into a new F23. An added bonus of the F23 is the ability to use the stock Fiero axles.

I plan to get a 2006-2007 LE5 for the forged rods vs powder forged rods of the later models. This way down the road I can add some boost, whether as a turbo or supercharger I am not sure. I could even throw an LSJ top end on it. Many possibilities.

Mechanically I am not worried about many aspects of the project, I have picked up Tig welding since my Fiero days which will be nice for fabbing some headers and exhaust. I intend to modify the stock cradle for the initial install by removing and replacing the front crossmember, and I will use round bushings and steel tubing as sleeves to fab mounts for the motor and transmission. Swap will also require a higher flowing fuel pump, and modifications to the shifter or custom mounting of cables to the transmission. I will most likely make a custom shifter as I think that the Fiero shifter leaves a lot to be desired. I will probably order some custom shift cables.

However I am venturing into the unknown engine-management-wise. I am unsure of what path to chose. The LE5 is run by the E67 ECM that GM makes, it is a highly tunable ECM as it runs many GM motors, and seems pretty ideal for using a stock ECM. However I have not yet delved into tuning stock ECMs and I do not know what kind of difficulties lie ahead for going to an eventual boosted application. I also do not know what kind of compatibility the ECM outputs will have with the stock gauges. I assume there will be challenges there. I would like to delete the drive by wire of the LE5 for simplicity and throttle response reasons (valid?). I do not know the complexity from an engine management side of things in going this route.

Other concerns include deleting all the extra jazz the ECM wants to see asides from the motor so it runs as a standalone ECM. I would definitely attempt to get the wiring and ECM from the same car that I get the motor from to minimize incompatibilities. It will most likely come from an automatic car as I am having a hard time finding an F23 in a junkyard that is not mated to a 2.2. So there are some concerns with the wiring harness of the auto working with the connectors on the manual trans, but these are minor concerns.

Another option would be to drop some cash on a Haltech 1500. It looks like an ideal tuning platform that would allow for a lot of future modification. I could run the stock gauges from it. Logging is very simple. Etc. It is ideal for an engine swap like this, but I think the E67 can do everything I want/need it to, and it will be far cheaper. I am just unsure what the difference in difficulty will be as I have very little experience with the engine management side of things. I could always get the Haltech later on since I plan to run the car on a stock tune initially.

I want to gain experience though so I am very willing to throw myself into getting the stock ECU to work by figuring it out as I go.

I am looking for suggestions and information, feel free to critique my plans, I have read as many Ecotec builds as I can find to formulate my plans.

My overall goals are for a very small lightweight motor that is easy to work on, cheap to replace, easy to find, gets good gas mileage, and can take some forced induction in the future.

Thanks for the help, I will definitely document the swap in my build thread and thoroughly document the wiring and ECM reprogramming to make this swap more accessible to more Fiero owners.

[This message has been edited by zkhennings (edited 03-09-2020).]

wftb MAR 09, 02:32 PM
I have an LE5 intake on my 2.2. As you know this intake was made for drive by wire. In order to get the car to idle I had to add a hole in the old cable operated throttle body. Worked fine after that.

I was looking at ecotec powered sand buggys on Youtube and they have a simple solution to DBW and they just mount the DBW pedal assembly in the engine bay (with the pedal removed) and hook the stock throttle cable to it with a simple bracket. That way you do not have to mess with changing the pedal assembly out. I think this is the video- https://www.youtube.com/watch?v=SHqnwrU972k The Sand rail guys are doing a lot with ecotecs. I think this guy mention Phil's Bug Shop ? as a source for engine management stuff but it might have been another video.

As you know I went the stock ECM/BCM and wiring harness from donor car route. To tune the car for turbocharging I bought the HP Tuners MPVI Pro. That was 650.00 and for tuning out VATS and lots of other things is pretty much a necessity for the stock ECM unless you get someone to do that for you. I am still waiting for someone to get a Haltec up and running on an Ecotec. Member 4thfiero used an Alphafab setup on his but I think they have closed up shop. After some initial cold weather tuning problems it seems to be working fine.

Edited to get the right video.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

[This message has been edited by wftb (edited 03-09-2020).]

zkhennings MAR 09, 03:24 PM
If I keep the DBW I will just install the pedal in the stock location, I just worry there will be some latency between pushing the pedal and having the throttle open, which is my concern with the DBW to begin with.

So you paid $650 for HP Tuners? That is good to know because while the Haltech costs $1500 it has free software. I was under the impression that I could do what I need to with a $100 HP Tuners license. Junkyards are not that cheap by me so I expect another $150-300 for the ECM and wiring harness from the donor, making the overall cost not as far off as I thought.
wftb MAR 09, 04:46 PM
If you have a friend that has an HP tuners system, you could just get them to purchase 2 credits and do the tuning for you. That would be the 100.00 solution probably. The older DBW systems like you are looking at have almost lineal response times as far as I know from reading old tests. Newer vehicles have so many systems reading the input from the pedal that there sometimes is a feeling of disconnectness according to some testers. However we own 4 DBW vehicles all less than 3 years old and I have not noticed any sort of lag.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

BillS MAR 09, 06:04 PM
LNF would be the way to go, although there would be added packaging challenges to fit the turbo etc. into the engine bay. It is a stronger engine built for more power - how much do you want? Good to 400-450 crank before you even need to go inside the engine.
pmbrunelle MAR 09, 06:46 PM
As I understand automotive history, drive-by-wire was implemented in large part for the purpose of adding lag to the throttle response.

Hence, I find your concern about the possibility of throttle lag to be a legitimate one...

Why did automakers want to add lag? Easy... emissions. When you have a rapidly changing, unpredictable airflow controlled by a driver's foot, it's hard to deliver just the right amount of fuel into the cylinder needed to maintain a stoichiometric AFR. If the engine isn't working near a stoichiometric AFR, it's polluting.

So, the ECU takes over the throttle control, and the physical butterfly can then follow the driver's wishes at some computer-determined leisurely pace... filtered and lagged such that the fuel delivery can follow easily.

I think the need for throttle lag is especially true with port fuel injection vs. direct fuel injection, due to puddling of the fuel in the intake manifold. Because of fuel that clings to the walls of the intake (i.e. wall-wetting), and then slowly re-evaporates before being sucked into the cylinder, fuel delivery into the cylinder cannot change rapidly.

DBW is good for emissions, and driving aids such as cruise control and traction control. If you don't want these features, I don't see the interest in using DBW. If you do, there would be some value in keeping DBW.

When I think of a cheap and compact commodity engine, I think of the Honda D16Y7 from the 6th gen Civics. From what I see on the Internet, people do turbo them (not necessarily with a stock bottom-end), but I haven't seen a turbo D-series with my own eyes.

[This message has been edited by pmbrunelle (edited 03-09-2020).]

zkhennings MAR 10, 04:07 PM
I have hit up the main Haltech distributor near me to get some clarification on some questions I have. I am leaning towards the Haltech at this point in time.
pmbrunelle MAR 10, 08:18 PM
When my work colleague bought a Haltech, he was able to get customer support direct from the folks in Australia.

For some questions, you may want to bypass the middleman, who may not have the answers to everything.

Ideally, you should pick a computer and then stick with it, otherwise, you'll be redoing your wiring harness just because of bad planning.
wftb MAR 10, 09:04 PM


I bought this megasquirt system from the mall and forgot all about it until recently. It was built by member fosgatecavy98. It uses the 7x crank reluctor wheel so would not run a 2.4. I bought it in case I want to do a stand alone 2.2 in something like a locust 7 but that project didn’t pan out

link to original discussion of this system http://www.fiero.nl/forum/A...160323-1-074398.html

It has been so long since I looked at this system that I do not know what all it can control. I know early Megasquirts could not control ignition and I suspect that is the case with this system. But new Megasquirt systems can control almost everything as far as I know. But you have to write a tune from scratch.

[This message has been edited by wftb (edited 03-11-2020).]

qwikgta MAR 11, 03:46 PM
Some pics of the DBC to DBW setup