Jump to content
HybridZ

Help me! Megasquirt 2.2 Board Fuel Only


78zstyle

Recommended Posts

I have so much trouble with this darn thing. AFRs keep fluctuating from 12-16 or what have you. In the mornings when I first start it, it runs pig rich with no warmup acceleration but runs much better when warm. My idle AFRs just keep going up and down, taking my RPM with it. Cruising is ok. I've attached my tune and a log of it idling showing whats going on. Any help would be appreciated. I have all EGO corrections turned off. Is it possible that the Original BG code just doesn't work right?

Datalog42512.txt

Link to comment
Share on other sites

What is your battery voltage doing at idle? Is it fluctuating as well? You may have to adjust injector compensation tables. I've recently adjusted mine (different system, not MS), and it has helped greatly with a surging idle I'd occasionally get.

Edited by Six_Shooter
Link to comment
Share on other sites

What is your battery voltage doing at idle? Is it fluctuating as well? You may have to adjust injector compensation tables. I've recently adjusted mine (different system, not MS), and it has helped greatly with a surging idle I'd occasionally get.

 

My battery voltage dies as the idle goes down (while its going rich at the same time). I've tried adjusting the compensation down and it gets way worse.

Link to comment
Share on other sites

My battery voltage dies as the idle goes down (while its going rich at the same time). I've tried adjusting the compensation down and it gets way worse.

 

Think about that for a minute.....

 

 

 

 

 

 

Ok....

 

 

 

 

 

 

Try adjusting it the other way, (increasing the numbers) at lower voltage. ;)

Link to comment
Share on other sites

I don't know any details of your car. Is this a stock cam and do you use a stock style cold idle valve that closes as coolant heats up? Are you using high or low impedance injectors and if they are low do you have dropping resistors or do you use PWM? Just trying to see if anything seems obvious to me that would make your idle hunt. Large injectors that are hard to control will cause it. A large cam may cause it, but I haven't personally witnessed how large cams act with megasquirt.

Link to comment
Share on other sites

I don't know any details of your car. Is this a stock cam and do you use a stock style cold idle valve that closes as coolant heats up? Are you using high or low impedance injectors and if they are low do you have dropping resistors or do you use PWM? Just trying to see if anything seems obvious to me that would make your idle hunt. Large injectors that are hard to control will cause it. A large cam may cause it, but I haven't personally witnessed how large cams act with megasquirt.

 

Im using the 240sx tps. Stock cam. Low impedance injectors with resistors no pwm.

Link to comment
Share on other sites

78zstyle, I downloaded your datalog and converted to .xls to open with MegaLogView. I'm guessing something must be lost in transation.

 

Your max RPMs are 71? Is that correct? And MAP only varies between 21 and 65? PW is pretty consistenly 1.3ms with occasional spikes to 6.3?

 

I'm assuming your file didn't translate correctly, or I did something wrong, because that data log is junk. No car will run like that.

 

Do these numbers correspond with what you are seeing?

Link to comment
Share on other sites

78zstyle, I downloaded your datalog and converted to .xls to open with MegaLogView. I'm guessing something must be lost in transation.

 

Your max RPMs are 71? Is that correct? And MAP only varies between 21 and 65? PW is pretty consistenly 1.3ms with occasional spikes to 6.3?

 

I'm assuming your file didn't translate correctly, or I did something wrong, because that data log is junk. No car will run like that.

 

Do these numbers correspond with what you are seeing?

 

Oh wow, you are right, I didn't look closely enough to see how low those RPMs were. In megatune while its running it shows the correct RPM, what gives?

Link to comment
Share on other sites

  • 1 month later...

I thought I'd give this a bump. I recently transplanted my engine into a new chassis and got a chance to double check all wiring. Everything is wired correctly, all grounds good.. etc. It's still doing this.. I really am considering just ripping megasquirt out and going with another ECU (Z31)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...