Rogue_Ant

Ok, this is pretty much all describing the same/similar thing. I do know the problem, and it stems from me doing the majority of testing at high altitude
Basically, since we use the MAP sensor as an axis for timing, we have programmed in some MAP sensor error checking. The DME constantly checks that the MAP sensor is "believable". It does this by a MAP vs airflow function. If it believes there is too much airflow and not enough pressure, then it will trigger an artificial limiter (like the rev-limit), and limp-home.
If there is an error, then the most likely trigger point is at the transition from vacuum to boost, because this is the point when the MAP sensor reading starts becoming increasingly important.

I had thought that there was enough "allowable error" programmed, as it works great up here (~5000+ feet). But, evidently, those at lower altitude, and especially with the bit thicker air from the cooler weather, are just touching this limiter/limp-home.

Gents, the fix is easy - I simply need to enlarge the allowable airflow range on your Tune.

Rogue_Ant

Looks like I have a bit too much response set into the idle. I am finishing up a complete idle-code re-write, that is significantly better than anything beforehand. And soon as I am finished, I will send you an update.


On E85, 50° is cold enough to make the car quite sluggish until the engine warms up some. I am working on a couple of ways to help this, via the Tune, but if E85 has a downside, cold-start performance is it.

zerMATT951

Joshua, I'm going to return the chip you sent along with that old MAF tree pipe on Monday. I'll just wait to do the chip swap until you get the new code in place.

I won't be driving the car for the next week or two anyway. My TO bearing was making a hell of a noise today, so I'm happy to have made it home. I won't be taking it anywhere until it's got a new bearing and clutch .

Zeff

Yo, I've had my Mtune on the car for about two weeks now. I didn't really get a chance to really evaluate it until this weekend driving down to Atlanta for the Mille event. I am very happy with the performance of the mtune, but I too have had some quirks. After the car is warm it will sometimes hunt for idle at stop lights (drifting up and down from about 800rpm up to 1400) This would happen more often after driving for a while then shutting the car off (gas, food etc) Twice during the trip the car would just increase the idle, revving up to about 3000 as if I was stabbing the gas at a stoplight. All of these seemed to correct itself if I tapped the gas. I originally thought that I had a bad tps also since I had some quirks last fall where my idle would be low, but resetting it from the Lindsey directions fixed it.

Josh - did you ever see my email?

Zeff

Yo, I've had my Mtune on the car for about two weeks now. I didn't really get a chance to really evaluate it until this weekend driving down to Atlanta for the Mille event. I am very happy with the performance of the mtune, but I too have had some quirks. After the car is warm it will sometimes hunt for idle at stop lights (drifting up and down from about 800rpm up to 1400) This would happen more often after driving for a while then shutting the car off (gas, food etc) Twice during the trip the car would just increase the idle, revving up to about 3000 as if I was stabbing the gas at a stoplight. All of these seemed to correct itself if I tapped the gas. I originally thought that I had a bad tps also since I had some quirks last fall where my idle would be low, but resetting it from the Lindsey directions fixed it.

Josh - did you ever see my email?

URG8RB8

Zeff

Mine does that too, hopefully corrected with new idle code. I am on vacation in Florida. Hopefully new chip will be waiting for me upon return home next week.

Dave W.

When my idle switch was going bad it would act normal when cold but worked bad when the engine got hot. No amount of adjustment would fix it.

To you guys who have cold start issues with E85, does the car fire up on the first try? Or do you have to crank it a few times before it fires?

Bri Bro

It would start, then stall. Second time it would run rough and then smooth out. This was with 40 degree weather. I switched back to gas for the winter and it goes into storage soon.

URG8RB8

It will not start on the first crank even in 70 degree weather, not on the second most of the time, almost always on third try. Fires up immediately with gas. The thing that worries me a little is the amount of vibration and struggling after it does fire up on e-85. Good thing I recently installed LR ultra mounts.

Bri Bro

That is a good point, I do get a lot of vibration until it runs a bit. E85 does give more power, I could tell the difference when I went back to gas.

zerMATT951

Mine only runs rough on the first start when it stumbles bad for a few seconds, then stalls. The next time I crank it, it fires immediately then runs relatively smooth while it warms up. Lowest temps so far have been high 30's to low 40's but the car is in the garage which probably isn't going much below 55-60 overnight.

Dave W.

OK it's not just me then!
Rogue, is there an ECT enrichment table that can be tweaked for the E85 users?

Rogue_Ant

Gents,
I've been doing a lot of work on the idle stuff - especially for the E85 maps. I am nearly done with the new code, and will update everyone as soon as I am finished!

URG8RB8

The power difference is amazing! Thus the reason I am sticking with the E-85. I am faithful that Josh will take care of us very soon. He is a great guy. I took my friend at work for a ride and he has a new M5 with the V10 and when I lit up the 295's at 40 in second he got scared and said R U kidding me this is a 2.5 liter four?

Rogue_Ant

Yep - a couple of guys are testing it now.
I am doing one more tweak (unrelated) this week, and then will do a mass-update next week.
Expect an email from me near the end of the week.