legacycentral bbs

Here's the backstory of my problem:

I have a Robtune ECU that died seemingly out of the middle of nowhere. I drove it one day, parked it, then the next day I went to start the Soob, and it wouldn't start. The fuel pump doesn't prime, and there is no CEL with key on (usually the CEL lights with key on).

I swapped in my old EJ22t ECU to test if the ECU died, and it fired right up with the EJ22t ECU, so I'm assuming the Robtune is dead. I haven't been able to get a hold of Rob to discuss if there is anything he can help me with.

Here's my question:

Can I swap out the Robtune and run the EJ22t ECU without issues if I keep out of high boost until I can get the Robtune fixed/replaced? I know I'll have a CEL because of the MAP ground, but is there anything else I should worry about?

Thanks all,
-Jason

Jason,

What version of the robtune are you running? If you used the ej22t ECU as a "test" ECU I'm guessing you're probably running the 440 injectors. Are you also using a 2-4 ignition converter?

Any additional details you can provide would be helpful.

All of my mods are in my signature (I have 440 grays and the 2-4 converter).

Here is what I emailed Rob initially for my tune parameters:

Here are the tune options:

Injectors GRAY 440cc

CEL knock indicator YES

Launch Control NO

Boost cut: OFF

Max boost: I have a TurboSmart EBC

Speed Cut: OFF

Rev Limiter: 7500

Warm Idle: STOCK

Remove CELs: Code44 for BCS, and whatever else you recommend

It's possible you have a bad ej20g board. What happens if you remove the robtune eeprom, and reconnect resistor J1 that was snipped on the ecu?

mike-tracy wrote:It's possible you have a bad ej20g board. What happens if you remove the robtune eeprom, and reconnect resistor J1 that was snipped on the ecu?

I will have to try this tomorrow or Saturday. What will this prove/disprove performing this test?

-Jason

If your car works as normal, then the robtune is bad. If the fuel pump still doesn't prime, then the ej20g ecu is bad.

Hopefully it's the ecu. While the ej22t ecu can run your setup on low boost, it'll run poorly and super rich.

mike-tracy wrote:If your car works as normal, then the robtune is bad. If the fuel pump still doesn't prime, then the ej20g ecu is bad.

Hopefully it's the ecu. While the ej22t ecu can run your setup on low boost, it'll run poorly and super rich.

Great, thank you for the info. I'll try today when I get home from work or tomorrow and report back what I find. Is resistor J1 fairly easy to locate on the board?

Yeah, j1 is labeled on the main circuit board, and should have one end snipped. All you need to do is add a blob of solder to the cut ends to reconnect it

Is there supposed to be a resistor here, or can I just connect the two ends of J1?



If I need a resistor, do you know the value of it so I can try to get one?

Thanks again,
-Jason

I opened up my ecu, but it isn't color coded. I'll de-solder it and get back to you about what size it needs to be.

OK Rob got back to me and said it is just a jumper. So you can solder in a piece of wire between the two pads

How did you get a hold of Rob? I've emailed him a few times this week with no answer?

I'm basically his neighbor

mike-tracy wrote:I'm basically his neighbor

Haha, right on, thanks man. I'll jumper J1 tonight and give it a try tomorrow and report back.

One other thing: I don't have a chip extractor, is the next best thing being really careful with a flathead jewelers screwdriver, or is there a better way?

Well, I couldn't wait. I removed the Robtune EEPROM, re-jumped J1, plugged in the ECU, and it fired right up. Just to check, I removed the J1 jumper, re-socketed the Robtune EEPROM, plugged in the ECU, and no start.

Sounds like a bad Robtune chip then?

There's a couple possibilities at this point:

Bad solder joints between the chip's socket and the ecu board
Bad connection between the chip and the socket (none of the pins are bent or missing right?)
The ecu's circuitry that reads from the chip got fried
Bad robtune eeprom.

You can check the first two by inspecting the eeprom's pins, and reflowing the solder to the socket itself (with the eeprom uninstalled of course!). The third requires a known good ej20g ecu with a socket.

Last night when I pulled the chip to test, all of the pins on the EEPROM looked fine, as well as the socket.

The socket itself may be the problem though. After close inspection, it looks like one of the pins for the socket doesn't actually go through the board:



You can see a pin from the EEPROM socket sticking out of the side. It probably makes occassional contact with the board itself, but I don't know for sure

I've never opened the case of the ECU before today, so it came like this from Rob. I would assume this isn't correct. Could this be the problem? The car has ran ok for a few years (there's always been an ignition miss since putting this ECU in), but since last Sunday it has been dead.

I'll email Rob and ask what he thinks, hopefully I will get a response from him.

Thanks again for the help.

I'm not sure what that pin does, but it could have had an intermittent connection issue as you mentioned. Best course going forward is to follow Rob's guidance.

What are you using to take pics? It does better macros than my Nexus 5x

Yep, Rob got a hold of me, I sent him a few pictures of the top and bottom of the board and am awaiting his response for next steps.

I used my Galaxy S6 to take the pics.

Ive been running my stock ecu on my ej22t block with ej25d heads on 550 injectos td06 20g turbo and on a turbosmart fuel cut defender at 22 lbs and the ecu does great however gotta change plugs rather often but it will work and will pull hard

chanley2010 wrote:Ive been running my stock ecu on my ej22t block with ej25d heads on 550 injectos td06 20g turbo and on a turbosmart fuel cut defender at 22 lbs and the ecu does great however gotta change plugs rather often but it will work and will pull hard

That can and does work in your case and others. But the Robtune brings the performance to the next level. It's not even close.

mike-tracy wrote:

chanley2010 wrote:Ive been running my stock ecu on my ej22t block with ej25d heads on 550 injectos td06 20g turbo and on a turbosmart fuel cut defender at 22 lbs and the ecu does great however gotta change plugs rather often but it will work and will pull hard

That can and does work in your case and others. But the Robtune brings the performance to the next level. It's not even close.

Ha, that's a dumpster fire of a tuning solution for sure. Brings me back to the old days with these cars pre-RevTronix and pre-20G ECU when your options were stock ECU with a FCD or junk piggyback, or a mega-expensive standalone. Now we have so many better options!