Megasquirt tuning problems

67Fairlane

New Member
Jul 19, 2022
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Cleveland, Ohio
Hi I'm new here, I've tried my best and am lost on tuning my Megasquirt... been trying everything from different forums and YouTube videos and gaining no ground.. my VE tables, AFR tables, and I'm sure timing tables are a absolute mess.. the car is either full rich or full lean.. I have a 67 Fairlane with a 306 N/A.. had been running a A9L pcm car ran great except for a rolling idle a d would stall at the worst time.. so I went with a Megasquirt 2.0.. just looking for some assistance to get thing ironed out..
 
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I haven't messed with this thing in 2 weeks.. if I didn't have so much money wrapped up in all the components I'd put a Carb on it and call it a day..
 

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Your commanded air fuel table and ve table are amazingly jacked up, so they were never going to work. Timing table is weird too, but it’ll run with it. The megasquirt stuff is simple, but you’ve got to take things slow.

In the afr table (not ve table!) select every cell in this red box and make it 14.0

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Then take everything in the ve table circled in red and make it 54.

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You really, really need to watch a simple video on YouTube or something on megasquirt setup. Your afr table is what your air/fuel would like to be, there is zero reason to ever make changes in that table. Whatever the base tune from the company you bought the ms2pnp from should be fine. The ve table is the only thing you should ever be changing, and it should be smooth.

You have a wideband right?
 
Thanks for the help.. yes I have a Innovate wide band.. right from the start before I messed it all up trying anything to get it to do something, the AFR gauge was pinned lean.. then it was pinned rich.. I'll use your information and see where it's all..
 
Thanks for the help.. yes I have a Innovate wide band.. right from the start before I messed it all up trying anything to get it to do something, the AFR gauge was pinned lean.. then it was pinned rich.. I'll use your information and see where it's all..
Ok good, just remember to only adjust the ve table, and do the whole group of cells at first tk stabilize the idle. If air fuel ratio is good and stable and the car won’t idle, then open the blade on the throttle body a little at a time until the idle duty cycle is around 15-20% with the car idling. Then reset the throttle position sensor calibration.
 
This is a update on my settings.. this is the best I've got this thing to idle.. I don't have much free time.. hope you can see that picture.. how ever at 18% throttle there is a flat spot if you gently tip in on the throttle.. if you goose it it seems to accelerates properly.. yeah I messed with all the tables prior to our last conversation watching to many videos of do this and do that.. so I'm out in left field, but I'm catching on slowly
 

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Looking better, but still work on it. The area on your ve table just past idle needs fuel. Notice how fuel flow goes down with rpm?

Also, the ignition table should not have 36* at 90 and 100kpa. Unless you have a super lazy sbf I’d set it at 32* past 3500rpm unless running low octane fuel. If then I’d set it to 28 or 29.
 
I can only get this thing to idle where it is 1120rpm with the iac unpluged and stop screw turned in... with it plugged in in idling at 1400-1450rpm
 

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I can only get this thing to idle where it is 1120rpm with the iac unpluged and stop screw turned in... with it plugged in in idling at 1400-1450rpm
So with the throttle body all the way closed it won’t idle below 1120rpm? STOP MESSING THE THE AFR TABLE. Fueling changes are made to the ve table ONLY, don’t screw around with the afr table, ve table only. You’re going to :leghump: your self up that way. Afr table is what you’re targeting, ve table is the actual fuel value.

Turn the car on, let it get above 140* and set ignition timing to 18* in the ignition table in the cells the car idles at. Start closing the throttle body screw until the car idles where you want it with iac duty cycle at 15-20% then calibrate the tps and you’re done setting the idle speed.

Try that and report back here. Don’t drive the car until that’s dialed in. The ignition table definitely has too much timing at 70-100kpa, but we’ll start with the idle first.
 
No leg humping I hope lol... I did what you suggested.. I'm sure there's more massaging to do, it's idling at 1230-1247.. maybe I'm getting close? Where I have the VE table set it the closest I can get it to 14.7 afr.. this is all new :poo: to me.. I appreciate you giving me a hand with this..
 

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No leg humping I hope lol... I did what you suggested.. I'm sure there's more massaging to do, it's idling at 1230-1247.. maybe I'm getting close? Where I have the VE table set it the closest I can get it to 14.7 afr.. this is all new :poo: to me.. I appreciate you giving me a hand with this..
That ve table is completely out of whack. It should be smooth, not have increases of 50+ values from adjacent cells. There are lots of good videos on YouTube about setting these up. You really, really need to watch some and study up. I don’t mean to sound harsh, but you will never, never get the car to run right if you don’t do some research.

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Look at how massive the changes are in this area of the table. You have a value of 72 and then 34 right next to each other
 
I know what your saying, I have been watching videos and have noticed other people VE table have the same numbers or not such a huge change in numbers, but if I do that the idle starts to scream up to 1400- 2000 rpm, for example.. (if I set my ve number to let's just say 56 all the way across the board on 50kph line the idle will create over to 1400+ Rpm) This thing is completely a pain in the ass, I'm about to toss it and put the factory computer back in and live with the ridiculous rolling idle.. I'll keep messing with it, I'm obviously missing something in the settings.. For example I discovered that for some reason the Map was switched off, I thought I was getting somewhere when I switched it to internal Map.. I have the IAC set at 31hz .. I article written by Diyautotune they suggest to keep the IAC set to Open loop the it should only be in closed loop with your using accessories like A/C.. also they suggested that timing should be set to Fixed timing...
 
Does the iac setting need to be inverted on those? 99hz is where it should be, you do not need to change it.

I would honestly load the tune from scratch what diyautotune gives you and start from there. It only takes a couple mins to enter your engine parameters.
 
I don’t know exactly what the settings are in ts from their tune, but it’s gotta be better than what you’re working with now.

Start by just turning off the iac, or unplugging it and get a decent idle afr and ve table sorted. Then work forwards from there. You can open or close the throttle blade on the tb to set idle up for now.
 
I figured out how to go back to out of the box settings the pictures i attached are the facorty settings... it starts without touching the gas pedal at least now.. but my reading on my AFR gauge shows I'm at 10.6 afr, I messed with VE table and the best I can get it at is 11.8 and it'll touch 12.0 afr once in awhile.. man if I would known I was gonna have this much fun with this thing, I woulda just put a carb on it and :poo: canned the entire thing..
 

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Dude you just need to bring down the ve values some. Notice you have a 45 right next to an 80? I keep telling you to smooth it out, but you won’t do it. Bring the damn 80 cell down
 
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