dizzyj

I received my mtune on Sat. Spend Sunday installing. Fairly straight forward install. I had one issue where my car would not start after the install. After talking with Joshua and pending some time here, I realized that the little box I disconnected under the passenger kickboard was the alarm brain, and that the car will not fire without that plugged in (or jumpered).

Once I plugged that in, the car fired right up. Once warm my wb02 reads ~15 afr. at idle (18hg of vac) (running premium 93octaine)

Only issue I have currently is that when I blip the throttle up to ~3k, the rpm's come down to about 2k and hover, then slowly come back down to 900 idle. I have not reset my idle yet (tonights task).

This is a pure track car, so I cannot really drive it around yet. Hopefully will get it to the track this weekend to test and tune.

dillon410021

I want one

User 52121

Resetting the idle to ~850 will fix that.

I installed mine 2 weekends ago and am pretty impressed with the improvement, even over the A-Tune. Part throttle and low boost stuff, the car *really* shines, but even at WOT the car seems to run a LOT better. Holds boost a little longer and just seems more willing to rev. Overall a much flatter power curve. And it takes a lot less throttle to rev-match - it's just a lot more responsive. (Heel/toe previously took a pretty healthy stab of the throttle pedal... now just a quick tap is enough.)

dizzyj

cool. I was not sure what resetting the idle would do. Knowing that it fixed others with the same issue is good enough for me.

I barley got to drive this car without mtune. I've spent the last 6 months rebuilding it and making it track worthy again. It was a lot bigger task that I had intended when I bought the car. Mtune was just the best way for me to get the car tuned correctly by someone who knew what they were doing. Otherwise I had an old maf setup and it was up to me to figure out what af ratios I wanted and how to set them

zerMATT951

The 2,000 rpm hold is by design per Joshua. I don't recall the technical reason for it, but you aren't going to make it go away by resetting the idle.

Zeff

Can you describe that hold a little bit... I don't recall my car ever doing that.

dizzyj

really? ok. I guess it should not matter to me, being a track car and all, but it seems like it would be a bit annoying on a street car.

I played with the idle screw a bit tonight, and it did not change the idle much (did not bypass the icv yet). I could not actually get the car to idle down to 850. it would only go down to ~1000, and bounce between 1000 and 1100 or so. My af's seem a little on the lean side mid-high 15 at idle. I have an adjustable fpr, and have it set to 3 bar (using a fuel pressure gauge).

I'm assuming each one of these cars might be slightly different and might need some of their own tweeks?

zerMATT951

I can't really, all I can tell you is that it's there by design for some reason. It may not be present in all revisions (there have been a few since release), but it's in the latest. Maybe Joshua will jump in and explain its exact purpose.

zerMATT951

Follow the procedure on Clark's garage... you may not have the desired results if you haven't bypassed the ISV properly, and it's also possible that your throttle body is leaking if it's never been rebuild/resealed.

dizzyj

when I rev the engine to say 3k. instead of having the rpm's fall off naturally till they get to idle, the revs stick at ~2k for a second or two, then slowly come back down to idle.

I have a brand new icv in my car, and it did not do this before mtune.

zerMATT951

It's nothing to worry about. Set your idle properly and you'll be good to go.

Mine has a couple other odd issues related to a somewhat flaky TPS. it's adjusted and tests properly, but I think it's got some dead spots and/or doesn't always close the idle circuit when hot. I'm going to pull it this weekend and see about cleaning it out, or I've got a spare I may test and swap in.

dizzyj

I get pretty damn good vac readings. 18in mg once warm. ill do the proper reset tomorrow and see how it goes.

Rogue_Ant

Yep, the slowing engine decel at ~2000rpm is right when the DME turns back on the injectors. The new software it should have a slight hold there and then decel slowly back to idle (850rpm in the latest software).

Some engines (such as mine), have a lightened flywheel/clutch/PP and have more of an issue with drop-throttle stalling. So I added in some 'help', to prevent that.

Earlier software, we bumped the idle speed up, so that it had more hp/tq to catch and prevent drop-throttle stalling. But many users wanted a more normal idle speed. Fine, so in this case we need to be a bit more aggressive in slowing the engine decel rate before it gets to idle.

It really shouldn't be very noticeable when driving. And, in-fact, nearly every new car does something similar. If it is a big deal, I can reduce the affect, and perhaps I will regardless for the update.

dillon410021

wow, you really thought of everything. I hope to get one later this year

User 52121

Well... FWIW... my car hung too (and I've got fairly recent software...) and resetting the idle made it significantly less noticeable. Hence my suggestion.