MSnS 1, Idle problems overlooked, tps threshold

[BigRand]

Okay, so my friend Ben, who helps me a lot with the megasquirt stuff comes back from my rival University (WA State), and figures out my idle issues in about 20min.

So this post is for future people looking for things to check while diagnosing an idle problem.

After playing with the Spark and fuel map trying to get my car to idle correctly, I got it to a point where it would idle around 700-900rpms, only problem is that it would have a droopy type of idle where it sounds like its missing.

Ben noticed that when we weren't touching anything on megasquirt, the injector pulsewidth was fluctating from 1.6-1.7 (where it idles good), to 2.3-2.5 for a split sec (where it droops or misses).

We checked the TPS signal, and noticed that it was kind of fluctuating as well around 0.0-0.2, but the affect this had was causing the megasquirt to go into an accelertion enrichment map for a split second and then back to normal. So we bumped the TPS threshhold to 0.9, and now the missing and droopy idle is gone. And maintaining a steady idle is now determined by the ramp effect in my spark table.

(pictures soon to come)

[Ajax]

So did my msq help at all with your cold start etc. bc mine is running really good! So you say you got your idle figured out-What did you use for an idle valve? Thats the only thing I really need to figure out yet, but I will check my tps bc my idle fluctuates aswell but I believe it bc of my stock IAC is still connected and messing everything up.

[VelocitàPaola]

Originally Posted by Ajax

bc of my stock IAC is still connected and messing everything up.

I've finally got a fix for that!

[Ajax]

Now you dont want me to go down on my knees and beg for it do you??? Bc I would!! I've unplugged it before but then I idle around 1600rpm which is not to bad but would be better if I can get it to idle at stock rpm.

[VelocitàPaola]

It's still being tested, but you can be a tester if you'd like.

[BigRand]

Originally Posted by VelocitàPaola

It's still being tested, but you can be a tester if you'd like.

Me too, me too.

And Ajax,your maps helped in refference but as far as actually fixing the idle problem, This TPS threshold thing is the big kicker.

[VelocitàPaola]

Sure. I'll probably make a thread about it shortly.

[Ajax]

I will try to change the threshold bc I just checked mine and it's set at 2.539? NO idea why!

[BigRand]

well ajax its different for everyone, just take a look at that menu while the car is on, and see how much your TPS signal goes up on its own at idle, and see if setting your Threshold above that makes a difference. FYI: you may have to re calibrate your acceleration enrichment map