xmacmiatax

Hi guys. Having a a problem with my 1.6 at idle. I have turbo 1.6 with a ms2 unit with flow force 550s.problem is afrs at idle are staying around 11 I’ve adjusted my table as much as I possibly can. The area that it’s idling at are all at a value of 1. And it will not lean out. I’m sure That maybe something stupid is set up wrong. I used the base map from diy to start from.other than that it idles great. Haven’t had a chance to drive it yet because I’ve been chasing this problem. Bottom end is also built.

HowPrayGame

Post tune and log

xmacmiatax

ive attached tune and log please go easy on me hahah. also log has a little bit of rpm jump from trying to play with the ase settings

SpartanSV

Your ECU thinks your battery voltage is 8.5. Fix that and you fix your fueling issue.

xmacmiatax

I saw that thought that it was funky. Where would I fix that at. Battery’s brand new. Assuming a setting In tunerstudio.

SpartanSV

If I had some direction for you I would have given it in my post.

You responding within 2 minutes of my post tells me you didn't even attempt to search for the information yourself.

It's your car man. Do some leg work.

xmacmiatax

I was looking when I sent that message back to you just didn’t know if you had an idea already. I do appreciate the help though. I’ll figure it out.

venetox

If your ECU is seeing 8.5 volts when the car is running the following may be true.

Your alternator is borked and your battery is at 8.5 volts, ecu will try to correct by increasing dead times, but if your curve is not correct it will way overshoot or undershoot.

Your alternator is fine and battery is fine, but you have high resistance connections causing voltage drop to the ECU. This causes the ECU to see low voltage, attempts to correct for it by increasing dead time, but if the voltage is not actually low and the injectors are getting correct voltage it will WAY overshoot and cause extreme rich conditions.
If this is the case you need to confirm you are grounding your megasquirt to the chassis, (also ensuring your sensors all go to a single separate ground wire on the ECU) and that your power to ECU is crimped correctly and etc.

You can test some things by doing the following, unplug Megasquirt, and use a Multimeter in Resistance mode to check for the resistance between the ECU Loom pins and a clean piece of metal on the chassis, if you it is not 0 or very close to zero you have an issue with your grounds.
If your grounds are fine, you need to look at the resistance between your Power cable for ECU and your positive cable of battery with Ignition ON.
This should also be 0 or close to.

You may also have leaking injectors or incorrect fuel pressure.

That's just my initial thoughts.

xmacmiatax

Battery checked out alternator checked out. I went into the battery calibration and bumped the high number up and now my gauge in tuner studio matches what my injectors are seeing for Power which Was 11.7v from what I’ve gathered from other post injectors seem to be lower than 14v when cars running and high 11s are normal.
My fuel table changed drastically after I switched the calibration number and I had to add fuel instead of taking it out my table is more balanced now around idle.

venetox

Sounds like the car is running better now but.

11V at injectors sounds low to me, if your battery voltage is around 14 and your injectors are at 11 (when car is off but key on) then they are having some substantial voltage drop.

The Megasquirt should be seeing exactly the same or very close to the voltage you get from using a multimeter on the battery posts.
If it isn't, you have voltage drop due to wire resistance which is an issue.


Are you measuring Injector voltage when car is off or on?

You will want to measure from the Injector 12V Feed to the negative of battery, if it is close to the battery voltage when the car is off but ignition on then the injector wiring on positive side is fine.
If that is fine then you want to make sure your ECU grounds are good, and the resistance from Injector Negative to ECU Trigger is zero or near zero.

If it is not you have an issue in the Injector Wiring loom, if it is then your injector wiring is probably fine and it may be your ECU grounds that are an issue.

xmacmiatax

Hmmm I’ll have to look a little more in depth. If I unplug the injector harnesss and messure voltage at the plug when car is on but off could that rule out that harness and it would most likely be a ground issue then right ?

venetox

Yeah that's the idea, it lets you test the harness so you can know it is not the injector harness, then you can move on to next thing which would likely be grounds.