Megasquirt 2 L28ET wont idle

[Don Don 23]

I installed megasquirt 2 on my l28et and i have had trouble getting the engine to stay on and idle. It will turn on and run for about 15 seconds going from lean to rich but it will eventually shut off. If i give it any throttle at all it will kill the engine faster or make it sputter. Is this just an issue with not enough fuel or something more, I also try to set the ignition timing on tunerstudio to  be the same as on the timing cover on the engine. When the advance on tunerstudio is at 12 degrees matching with the timing cover on the engine, it wont start at all but when i start adjusting the timing the complete opposite way then the engine will start. I am using a timing light with the  engine cranking and injectors unplugged to check the timing because it was jumping too much with the injectors plugged in. 

[turbogrill]

21 hours ago, Don Don 23 said:

I installed megasquirt 2 on my l28et and i have had trouble getting the engine to stay on and idle. It will turn on and run for about 15 seconds going from lean to rich but it will eventually shut off. If i give it any throttle at all it will kill the engine faster or make it sputter. Is this just an issue with not enough fuel or something more, I also try to set the ignition timing on tunerstudio to  be the same as on the timing cover on the engine. When the advance on tunerstudio is at 12 degrees matching with the timing cover on the engine, it wont start at all but when i start adjusting the timing the complete opposite way then the engine will start. I am using a timing light with the  engine cranking and injectors unplugged to check the timing because it was jumping too much with the injectors plugged in. 

 

I would recommend to post logs and maybe Chickenman could comment on those. 

Sounds like your timing is wrong as well. Could you run the stock timing? It's always good to get fuel only working first.

[Gollum]

For what it's worth I think my crank timing is 15 and I couldn't do a distributor sync at 19 degrees locked as the engine didn't want to idle down there. I bumped it to be 20 (locked) and it was much easier to get started and synced. Put the size wherever it needs to be to get it running before bothering about perfection.

 

As for fuel, it sounds lean. Give it more VE in the idle area and see what happens (go up by like 20% to be sure you're going past what's necessary, which should prove that you're lean).

 

Also, try not to trust a wideband when you can't get a stable idle. Even with sequential and a perfect idle it can still be difficult to get a reliable AFR reading.

 

Generally it's better to be too rich than lean if you're running batch fire, but most engines are also much happier to idle at 12:1 than 15.5:1. You'll also know if you have too much fuel because more throttle makes it rev readily since there's already excess fuel looking for air.

 

That said, if you're ignition is too far off, it'll never idle, which is why I mentioned just getting the timing in the ballpark regardless of what the timing light says.

[Don Don 23]

On 2/6/2019 at 11:05 PM, Gollum said:

For what it's worth I think my crank timing is 15 and I couldn't do a distributor sync at 19 degrees locked as the engine didn't want to idle down there. I bumped it to be 20 (locked) and it was much easier to get started and synced. Put the size wherever it needs to be to get it running before bothering about perfection.

 

As for fuel, it sounds lean. Give it more VE in the idle area and see what happens (go up by like 20% to be sure you're going past what's necessary, which should prove that you're lean).

 

Also, try not to trust a wideband when you can't get a stable idle. Even with sequential and a perfect idle it can still be difficult to get a reliable AFR reading.

 

Generally it's better to be too rich than lean if you're running batch fire, but most engines are also much happier to idle at 12:1 than 15.5:1. You'll also know if you have too much fuel because more throttle makes it rev readily since there's already excess fuel looking for air.

 

That said, if you're ignition is too far off, it'll never idle, which is why I mentioned just getting the timing in the ballpark regardless of what the timing light says.

Ok so I added a lot more fuel to the low end and now I can get it to idle and rev but it starts out idling like at 11 or 12 and eventually just keeps going more lean until it's like at 20, I added A LOT more fuel too. It doesn't make sense that it is reading that lean when i rev it or when it idles for a few minutes. Do you have any suggestions?

[Gollum]

Any chance you can share your tune and log file(s)?

 

If you mean it leaned out as it sat at idle and warmed up, I'd suspect you're still to lean on the VE table and WUE is to blame for the rich to lean transition.

 

If you mean it leans out as you rev it, that could be AE being not aggressive enough (mine was WAY too mild from the base tune), or if even bringing up rev slowly causes a lean condition then either your VE table needs adjustment in those areas as well, or your Req fuel might just be really out of whack.

 

Start by sharing tune data and some logs, and we can go from there.

[Don Don 23]

2 minutes ago, Gollum said:

Any chance you can share your tune and log file(s)?

 

If you mean it leaned out as it sat at idle and warmed up, I'd suspect you're still to lean on the VE table and WUE is to blame for the rich to lean transition.

 

If you mean it leans out as you rev it, that could be AE being not aggressive enough (mine was WAY too mild from the base tune), or if even bringing up rev slowly causes a lean condition then either your VE table needs adjustment in those areas as well, or your Req fuel might just be really out of whack.

 

Start by sharing tune data and some logs, and we can go from there.

How do I copy my tune data from tunerstudio to post on here?

 

[Gollum]

In your tunerstudio projects folder you should have a "currenttune.msq" file you can add to a post by the "drag files here to attach or choose files..." feature of the forum posting window.

 

[Don Don 23]

4 minutes ago, Gollum said:

In your tunerstudio projects folder you should have a "currenttune.msq" file you can add to a post by the "drag files here to attach or choose files..." feature of the forum posting window.

 

 

correct tune 2019.msq

[Gollum]

 

Several points:

 

Make a huge "idle area" for advance, that will save you piles of headache while you get up and running to get things running nice. I'd recommend using the L28ET factory setting of 20 degrees.

 

Your VE table is also VERY low in the idle region. That might be fine for some engines, and some injectors, but don't be afraid of running 50+ in that region.

 

I'd also flatten out the AFR table for the high vacuum, low PSI area until you have a known solid VE table. Never give your ECU a chance to "miss" an AFR calculation by 2 points because your VE is off and swing from 16:1 to 18:1. It's much better to push the AFR table rich everywhere, and then lean out the table once VE is known as close/reliable.

 

Making the suggested changes, might look something like this:

[Gollum]

Also, look at your AFR table, It goes from 13.5 to 16:1 AFR at 30pka from 800 to 1100 rpm. That's an intense step, and will get extrapolated everywhere above idle. That 16:1 target is insanely lean imo. You wouldn't touch it stabbing the throttle wish pushes the map up, but that's still crazy close to idle range imo. That's also ASKING for detonation if you're pulling away from a slow roll in 2nd gear (like if you came up to a light turned green before you came to a stop).

[Don Don 23]

ok so when i adjust the ignition timing on tunerstudio in the tables do i need to check anything with the timing light? I synced the trigger wizard at 12 degrees on the computer and on the engine so is that all the adjusting i need to do with the timing light? sorry for the noob question im just trying to learn the tuner studio system.

[Gollum]

Syncing the engine to MS:

Use the "fixed advance" pull down in your ignition settings, and set to 20 degrees. Check engine with timing light and get to 20 degrees or as close as you can. Lock down distributor. Now you can switch off of fixed advanced back to table, and generally never worry about syncing again. If you're already done this at 12 degrees and felt like you had good results, then leave it be.

 

Once you've done that sync, feel free to adjust the table to your hearts design, just err on the conservative and keep timing lower in the load regions to avoid detonation until you're ready to tackle that.

 

For reference, here's my tune (which is far from perfect, so don't treat it as gospel, plus it's not a factory combo)

[Don Don 23]

Alright thank you for all your help man, I will give all this a try next time I get a chance.

[Don Don 23]

34 minutes ago, Gollum said:

Syncing the engine to MS:

Use the "fixed advance" pull down in your ignition settings, and set to 20 degrees. Check engine with timing light and get to 20 degrees or as close as you can. Lock down distributor. Now you can switch off of fixed advanced back to table, and generally never worry about syncing again. If you're already done this at 12 degrees and felt like you had good results, then leave it be.

 

Once you've done that sync, feel free to adjust the table to your hearts design, just err on the conservative and keep timing lower in the load regions to avoid detonation until you're ready to tackle that.

 

For reference, here's my tune (which is far from perfect, so don't treat it as gospel, plus it's not a factory combo)

If I may ask what setup are you running on your engine?

[Gollum]

F54 block, stock turbo bottom end (dish pistons)

MN47 head (high compression penut chamber)

Non-intercooled

Factory T3

D585 LS coils

MS3X

Ford 260cc injectors

DIYautotune in-dizzy Nissan trigger disk

Factory fuel pump

Pallnet rail

Factory FPR

 

 

Any other details feel free to ask