V1 Custom / Aftermarket ECU for LSJ

[mike_sno]

Hi Forum,

as I am getting more and more ready with the mechanical part of my car, I want to focus on the software side. Having already quite some stuff purchased for getting information out of the current GM world (can adapter, Display,...) and my recent tuning experiences I am at a point where I am thinking of switching to an aftermarket ECU.

Missing items for me with the stock ECU are:
- No wideband O2 sensor.
- No flexfuel sensor

I wanted to see if there is some more interest in the going down this route and possible support from the forum.

While over time I have looked at different aftermarket ECUs Speedunio, Megasquirt, Haltech, latest I found the rusEFI which seems to be the most promising one.

I contacted rusEFI and they would create a custom PCB which could allow for fairly simple drop in replacement. Minimum order qty would be 10 and price would be $500.
Plus the price of the ECU. Which still seems to be cheaper than other ECUs. Here is a good overview of the signals which are going to the ECU.

I wanted to use this thread to gather around some people who are interested in this.

 

[Gtstorey]

The dependability of aftermarket ECM's is lacking compared to OEM. And the dependability of the "off" brands is even worse. Even the Holly stuff often only last a few years.

You really don't need a wideband to make it run correctly.

 

[mike_sno]

You mean with dependability how long they will work before damaged?

What's the lifespan of a factory ECU? Mine is from 2007.

Wideband alone is not the only reason, it is on reason. Please don't take that out of context.

 

[Dale E]

So, why? Just why? If you want to go full on racing or something there seems to be no need in an aftermarket ECU/PCM/ brain!
Many long running Locost Seven cars are running Megasquirts, Haltech, etc for many years -- street and race scenarios.

My Birkin Seven was built in 1999 and has a really outdated MBE ECU. Never had a problem.
My 2006 built Stalker V6 SC with a 1999 Buick engine and stock -- gutted never tuned ECU runs fine. Some Goblin owners have driven it so if they want they may chime in.
My 2003 Cadillac Northstar V8 with stock ECU and 430,000 miles later it is one of the most reliable cars I own.
My 2003 Buick Regal V6 SC is running great with over 216,000 miles.
My 2004 Pontiac Grand Prix V6 with 200,000 miles runs great.

Will you own your Goblin that long? How much reliablility are you looking for? I've seen all the Goblin builders woes in buying HP Tuners and messing with numbers and adjusting the ECU settings and heard their I can't get it to run at idle, it bucks and stuff off idle, I get codes - what are they? Add fuel here, timing here, does the engine breath and poop better? Hmmmm. well change some more.

Make sure all your electrical connections are solid and ground, ground, ground.

I guess I'm just too old and fashioned to entertaining something that the factory spent millions on to be changed!

Apologize for the rant and if I offended anyone reading this.

But, it's your car, so do what you want -- that's the beauty of kit building.

 

[mike_sno]

I'm a little confused. This is not about going aftermarket or not. this is not about my tuning skills or how my car is currently running (if it would be and you can help me with figuring that out, please stick to my build log. I am happy for any help in that case or I can pay a tuner a few bucks and I'm sure they figure the idle issue I have out. And, I'm not claiming to be the world's greatest tuner.) My strong suite is on the software and electronic side.

Just because it's software or electronics and not something to fix with a wrench and a hammer, you don't need to shy away from. Otherwise why I'm modifying anything on my engine? Why did I even buy a goblin and not just a 911GT3. Everyone can buy something from the shelf.

Why is there a market for stand alone ecu? I guess that's a list of reasons. For me flex fuel is important. I wish the engine would run close loop in power enrichment, yes, I'd love to have more control over idle. I'd also love to get more information out of the engine on a custom dash, I don't like the attitude which is in the hp tuner world, I'd love to have the possibility to change timing without reflashing the ECU when I'm on the dyno, I'd love to avoid a second tune for gas/E85 (I saw someone on this forum talking about getting a second ecu with a different tune) , i hate the limitations of hp tuners and the possibilities to read WB over serial. Are there tuners lowering the knock detection and deactivating the MAF? I'm sure yes. It's that what I'm behind? No. If the argument is someone spend a fortune in development costs. I guess I stick with stock as much as possible. Proven reliability over thousands of units and millions of miles.

I can possible Design the pcb for the drop in adapter myself, but would love to have more than just me tackle this. This post is about to finding this out. If it turns out I'm alone, that's fine. If it turns out there are more members interested, great. This community and many open source projects have worked with have shown me what a string team can achieve.

The journey of my goblin has teach my skills I thought I'd never learn. Decking the head is one of them. Does that mean I'm ready to rebuild the complete engine? No. Would i like to have variable cams? Yes. It's probably possible from a mechanical side, I'm very certain that you can't control that with the stock ecu.

Hope that answered your questions and brings this post back on track.

 

[Ross]

rusEFI already sells an E67 ECU for $600. I'm not sure what the hellen-e67 version of this ECU is, but the plugs look like our LSJ P12 connectors.
I wonder how many sensors are different between the LE5 2.4L engine (which runs the a E67 and has a flex fuel sensor) and the LSJ 2.0L engine.
Might even be able to run a Chevy E67 on an LSJ, just need to research the sensors, reluctor wheel, etc.

rusefi_documentation/Hardware/Hellen/hellen-gm-e67-b-schematic.pdf at master · rusefi/rusefi_documentation

User documentation for rusEFI engine control unit. Contribute to rusefi/rusefi_documentation development by creating an account on GitHub.

github.com

 

[Rauq]

I'm actually picking up where you're coming from. There's not a lot of HP Tuners access in the P12 and not a lot of information out there in tuning them. Things I wish the P12 could do that it can't:

• See more than 215kPa
• Idle airflow/advance control
• Flex fuel (max 11,100Hz, last LS I tuned went to
• PE CL
• More MAF range

I don't think the E67 can do PE CL, but even if it could, I don't think it can be made to work with the LSJ reluctor wheel, which is not easily swapped. That leaves an external trigger wheel to get most of the above.

On the other hand, you can make power and run well on a P12. Last time I talked to Justin Reed, he was still on a P12, and I am running one too. Don't think PE CL is the only way to safely make boost. The only reason I haven't made an E85 tune yet is because my toy hauler's fuel tank also supplies the generator which can't run E85. The P12 does have a single field to change stoichiometric ratio which can be easily calculated with a handheld ethanol content tester. Then I will just add a bit more spark timing and do a little tuning there.

I will say, I think you're overcomplicating things chasing inconsequential millivolt and millisecond discrepancies trying to pipe wideband O2 data back into your datalogs. Run an alternate ECM because you want to, not because you have to.

 

[Gtstorey]

Warning to LNF owners for a group buy, rusEFI says Direct Injection is "in development" on their website.

I looked at some of the aftermarket fuel injection systems last year when my e69 ecm lost a driver to the o2 heater since the E69's are a little hard to find. There are several of these companies popping up and seemingly disappearing shortly afterward. Service after purchase can be very spotty and failures out of the box are common.

If someone wants to try it, just buyer beware as with anything and don't get sucked in by a pretty website. HPTuners has a standalone that was supposed to have been out this last spring and still nothing. If you watch the "Roadkill" branded shows, you see Holley failures fairly often. And this stuff isn't replaced under warranty after a very short period.

 

[Ross]

• PE CL is Power Enrichment Closed Loop?

Power Enrichment (ECU requesting a richer fuel mixture say 12.5:1, to give more power)
Closed Loop (The ECU is checking the O2 sensor and adjusting the fuel mixture if too rich or lean)
Currently our P12 ECU only does closed loop when the engine is running stoichiometric (for gasoline, that is 14.7:1 fuel mixture)

 

[Gtstorey]

Narrow bands can only check close to stoich. so PE has to be open loop on most older GM's. The LNF is the exception.

 

[Rauq]

• PE CL is Power Enrichment Closed Loop?

Correct. I'm not aware of any GM 4 cylinder port fuel injected ECMs that use the wideband in power enrichment; I think aftermarket is the only way to achieve that. Theoretically makes tuning a lot easier. I brought it up because @mike_sno has wideband on his ECM wish list, even though the P12 can read an aftermarket wideband with minimal additional wiring.

 

[mike_sno]

Correct. I'm not aware of any GM 4 cylinder port fuel injected ECMs that use the wideband in power enrichment; I think aftermarket is the only way to achieve that. Theoretically makes tuning a lot easier. I brought it up because @mike_sno has wideband on his ECM wish list, even though the P12 can read an aftermarket wideband with minimal additional wiring.

It can read it, but the information is not processed.

Warning to LNF owners for a group buy, rusEFI says Direct Injection is "in development" on their website.

Correct, this is about the LSJ.

rusEFI already sells an E67 ECU for $600. I'm not sure what the hellen-e67 version of this ECU is, but the plugs look like our LSJ P12 connectors.
I wonder how many sensors are different between the LE5 2.4L engine (which runs the a E67 and has a flex fuel sensor) and the LSJ 2.0L engine.

I'll start comparing the P12 to the E67 ASAP.

 

[Tinkles]

I have a MS3 Pro Evo sitting on a shelf for my Goblin whenever I end up working on it again. I looked into Megasquirt due to brand recognition and years of hearing about people using it successfully. Coming from a P11(i think) ECU, 03+ Cavalier/Sunfire, where HPT only allows access to 1 spark table and 2 fueling tables(or 2 spark and 1 fuel, I forget exactly), RPM limiter, speed limiter, and torque management with Alpha-N. I was blown away by all the features that the MS3 has and it sold me on it.

I am not sure how much I can contribute since I have yet to install my MS3. But I have intentions of trying to have it read the "ABS" wheel speed sensors to run traction control. I would like to use the built-in nitrous control and a bunch of the other features that it offers, but cannot remember of the top of my head.

 

[mike_sno]

Is this correct according to your knowledge?

.
i can tell you for a factthat the lsj crank trigger is 60-2, or 58x, whatever you prefer to call it.

Crankshaft Reluctor Wheel
The crankshaft reluctor wheel is part of the crankshaft. The reluctor wheel consists of 58 teeth and a reference gap. Each tooth on the reluctor wheel is spaced 6 degrees apart with a 12-degree space for the reference gap. The pulse from the reference gap is known as the sync pulse. The sync pulse is used to synchronize the coil firing sequence with the crankshaft position, while the other teeth provide cylinder location during a revolution.

Camshaft Position (CMP) Sensor
The camshaft position (CMP) sensor is triggered by a notched reluctor wheel driven by the camshaft. The CMP sensor provides four signal pulses every camshaft revolution. Each notch, or feature of the reluctor wheel is of a different size which is used to identify the compression stroke of each cylinder and to enable sequential fuel injection. The CMP sensor is connected to the PCM by the following circuits:

•A 5-volt circuit
•A low reference circuit
•A signal circuit

All of this came from here Link

 

[Rauq]

I do believe the LSJ is 58x, but the reluctor is clocked differently than an E67 58x, and I was never able to find any indication that the E67 could be made to compensate for the different position of the missing tooth.

What do you want the ECM to do with the wideband?

 

[jirwin]

Was looking up some info on the reluctor because I thought the LSJ was something other than 58x (it is 58x after all) and stumbled across this:

Want to run an E67 computer in your LSJ powered car? Its easy! - Cobalt SS Network

2.0L LSJ Performance Tech - Want to run an E67 computer in your LSJ powered car? Its easy! - Wayyyyyyyy to much time was spent researching all of this on my end. Just tonight I found out exactly how easy it is. Read on young padiwan... The stock LSJ computer is called the P12, and is almost...

www.cobaltss.net

 

[Rauq]

If you follow that all the way through, the information on how to tell the E67 to look for the LSJ's missing teeth in a different location was never provided, unfortunately.

 

[Gtstorey]

lwrs10 was also on HPT forum and don't see any info there either

If you follow that all the way through, the information on how to tell the E67 to look for the LSJ's missing teeth in a different location was never provided, unfortunately.

 

[mike_sno]

I looked into the P12 from 2007 the LSJ, the E67 of the 2006 2.4L Cobalt and the E67 from rusEFI mentioned from @Ross above.

I also looked at the links provided from @Gtstorey Gtstorey's link @jirwin Jirwin's link

I created this table to see if there is a way to make that work.

Here are a few comments and things I found out.

1. The E67 pinout seems to be different depending on which car it is installed. E.G. a car with V8 has a different pinout than a 4cylinder car. Means E67 is not equal E67.

2. Based on 1. I believe the E67 from the 2006 2.4L Cobalt seems to be the closet one and as mentioned in one of the links. Seems to have the same OS.

3. The reluctor is different between the LSJ and the LE5. Swapping seems to be not easy. Both are 60-2 or 58x, but the knock out is different. This seems to be the issue which Iwrs10 has never shared how to change that in the firmware with a hex editor. This should not be a problem for the rusEFI as it has a trigger offset. With the information from the shared links we have a good starting point.

4. The P12 and E67 and rusEFI E67 have different connectors! P12 has 2x 56 and 1x 73, the E67s have 1x 56 and 2x 73.


What now:
4. makes me believe that Iwrs10 had not only to repin, he had to completely exchange plugs. Nothing what I am planning to do. I want a plug and go version where I can always swap back to the P12. After building the harness I rather spend 100h building a PCB than repin a connector and be offline for an unknown time.

I think the way going forward would be:
A: Building an adapter harness or plug in adapter from the rusEFI E67 to the LSJ harness.
B: Building a plug in adapter for one of the other rusEFIs.

A: doesn't make a lot sens if I look at the price. $600 for the rusEFI E67 + the issue of an adapter/harness. Officially an adapter would cost $500 for 10 boards. Brings me to $1100 and if the rusEFI E67 breaks, I have to replace it with another rusEFI E67 for $600.

B: seems to be the better alternative: $370 for the Ultra Affordable EFI 121 pin with crimp kit and metal enclosure. Than I would just need to make an PCB adapter with plugs matching the P12 Plugs and some solder points for the wire which are at the end of the crimp kit. That should be a fairly simple PCB which will cost me probably less than $10 each (but have to buy 10 each minimum qty and probably 2 iterations) for the PCB and some money for the connectors.

Here is my issue: I can not find the matching plugs to the P12 ECU online. I find plenty of sides where you can get the harness side of the plugs, but I can not find the ECU side of the Plug. Anyone an idea where to find them? The plus are:

56-Way F Micro 64 Sealed (BU) --> 2x the male version if possible with solder connection are needed.

73-Way F GT 280 Micro 64 Sealed (BK) -- > 1x the male version is needed if possible with solder connection.

I also signed up for the rusEFI forum and will post there. Will share a link to the post once done. rusEFI must have the source for the Plugs as they are used in the rusEFI E67.

rusEFI has a bulk order buy 3 get 4, FYI.

 

[mike_sno]

Option C would be: Make an PCB adapter from the rusEFI UA121 to more than 1 other cobalt engine. Like 1 adapter, which could connect the rusEFI 121 to the multiple engines.

This would be still cheaper as buying HP tuners with credits. Just a thought.