Sanity check, please...

[ddnspider]

I believe you will be leaner because you don't have the same gasonline content as the non-ethanol gas, meaning you will have positive fuel trims.

[joecar]

Stoich AFR's:

E00 = 14.6
E10 = 14.2
. . .
E85 = 9.7

(E00 is shorthand for straight gasoline)


So you can see that as the alcohol content increases the AFR ratio decreases, so you need to add fuel, this is done by editing B3601 (if your ECM does not handle flex fuel).


If you let the trims handle it, then you will see incorrect fueling when going to PE (positive trims are added, negative trims are not).

If you're running OL then you're not trimming so you will have to edit B3601.

[BLK02WS6]

Sorry I haven't been around - busy life with 2 little ones and work...

The above discussions are why I tune using lambda instead of AFR - takes into account blended fuels when correcting tables. When I finish, if trims are posative when I re-enable them, I adjust B3601 (usually to 14.2 because E10 is pretty much everywhere here).

[EagleMark]

Years ago I would notice BLM (LTFT in OBDI) were consistently adding fuel and I found the Desired AFR or Stoich setting was a perfect fix for this. At the time I thought it was a cheat when actually that is the first thing you should start with!

Joe talked me into Lambda and at first I had a hard time wrapping me head around it? Then a little more knowledge proved that AFR is so wrong... Lambda is so accurate and simple!

There's very few people who consistently go out of there way to run Non Ethanol that starting a tune at 14.13 is the way to go.

[Rich Z]

Hit a slight snag the other day.

I had the car out on Wednesday doing some more logging and when I had it in some low level boost trying to get some map cells populated, I noticed a, well, engine "burp" is about the best way to describe it. Never had that before, so it did kind of unnerve me a bit. I thought, "NOW what?" But the car got me back home OK. I actually did another tune and took the car out again, but didn't go into boost, and the car drove OK, but seemed rather rough at idle. And the timing looks a bit squirrelly too. Backing up a little bit, when I loaded that tune (#0027) I was pulling off of the garage apron and noticed that the oil pressure gauge was reading ZERO. Yeah, THAT caught my attention! But then I noticed that all of the gauges were dead. So I pulled back onto the apron and found out that I couldn't get the EFILive box to talk to my PCM. Sheesh.... So I just shut everything down, disconnected the V2 cable and rebooted the PC, and luckily I could then talk to the PCM again. But odd thing is that the gauges wouldn't come back until I reloaded that same tune again. :shrug01:

But the car seemed to run OK after I took it out again, but I didn't run it up into boost at all, which is probably a good thing.

Later on in the evening, I was looking over the log for that run where I had the hiccup, and I noticed something odd right where the hiccup should have been in the log.



Looked like timing advance just gave up and dropped to zero. This appeared to correspond ALMOST with a bump in the engine rpm trace, but not exactly. It seems to lead it a bit. The drop in advance seemed to line up with a slight rise in RPM, and then it dropped down. Then I noticed that the boost reading from the MAP sensor dropped like a rock right after that dip in spark advance. The more I thought about it the more it seemed likely that I had a boost pressure leak suddenly show up. But it is kind of a puzzle why the timing advance drop seemed to precede the boost drop out.

So today (Thursday) I popped the hood and started poking around. First thing I noticed was that it appeared that the airbridge had been rubbing on the underside of the hood again. Then I noticed something was different about the airbridge plumbing.

Here's a pic of the airbridge plumbing right after I got it put together.


And here we have what I noticed today.


That gap showing the aluminum tube between the two clamps was completely gone. And the bottom of the airbridge had come loose completely of the MAF sensor housing.



Sigh......

So I've got the airbridge and MAF sensor pulled out of there now. One thing I did find out is that the reducing coupler between the throttle body and the aluminum tube going to the air bridge is really not rated for boost. Summit's website didn't indicate that and I only found out by going to other sites trying to figure out what the thickness and number of plies are in that coupler. Apparently there are NO plies and it is just simply a single ply of rather flexible silicon. I thought it seemed rather soft when I installed it, and my guess is that it is way TOO soft and it was possibly ballooning out under pressure, pulling on the airbridge. But how that aluminum tube got sucked further into that coupler kind of has me baffled.

And this might even explain why I wasn't able to get over 8 lbs of boost out of those 10 lb wastegate springs.

In any event, I've got a new coupler on order that is supposed to be designed for boost conditions, so I guess the car is dead in the water for a bit waiting for that part to show up. In the meantime I'm going to cut away that part of the MAF housing that is supposed to fit into a notch on a coupler or airbridge so that the airbridge fits more snuggly on that end. I was actually looking for an aluminum MAF body, but couldn't find anything that looked like it would be an easy replacement. I'm not sure if that plastic MAF housing is getting too pliable when it gets hot, and therefore allowing the lower part of the airbridge to slip off of it. Anyway, all of the aftermarket stuff I looked at was either too long, or too wide, or both, which would mean too much fabrication to get it all back in place. So I'll just have to see if what I monkey around with when the new coupler comes in holds up well enough or not.

[joecar]

Rich, thanks for posting that... it shows the importance of thinking and visual inspection as the first steps of troubleshooting.

[ddnspider]

Isn't modifying cars a blast First thing I thought of when I read the first paragraph was that you had a coupler blow LOL. I've had a car shut off during a pull when a coupler blew off lol. At least it wasn't the motor, right?

[EagleMark]

First thing I thought of when I read the first paragraph was that you had a coupler blow LOL. I've had a car shut off during a pull when a coupler blew off lol.

One time blow off valve?

[Rich Z]

Isn't modifying cars a blast First thing I thought of when I read the first paragraph was that you had a coupler blow LOL. I've had a car shut off during a pull when a coupler blew off lol. At least it wasn't the motor, right?

Yeah, that did cross my mind when that hiccup happened. But when the car continued to drive OK after a few minutes, I figured the engine was OK.

I really think most of my problem is that darned plastic airbridge. It just gets pliable when hot. Which allows things to move around that you really don't want to move around. I'd like to get one of those gopro camcorders and see if I could video it while driving under boost. It probably blows up like a balloon. The place I bought it from said it will hold 20+ lbs of boost, but I doubt it will do that if it's hot. I've heated it up and then tightened down the clamps, but I'm afraid to REALLY crank down on them. Particularly on the end that wraps around my MAF sensor housing. The housing is only plastic itself. I actually have one of those aluminum BBK airbridges that I used to have on the car, but for some reason after the engine upgrade, it just no longer fits properly. Or at least I haven't found the magic combination of swear words yet. Maybe I'll take another look at it while I have the plastic airbridge off. I would REALLY like to have metal plumbing from intercooler to throttle body. The problem is getting the plumbing over the radiator upper support. I could get four inch tubing and figure out the bends I need, but that just won't fit between the hood and the radiator support. I really don't want to drop down to three inch plumbing.

Maybe I need to put some modelling clay on top of that radiator support and close the hood on it to try to figure out exactly how much clearance I have.

Yeah, once you go past just a single mod on your car, the interactions between multiple mods can throw some daunting challenges at you to try to get it all PHYSICALLY working together properly. Each mod is designed apparently with the premise that it will be the ONLY mod on the car, with no allowances made for any other mod that might be in place.

[ddnspider]

One time blow off valve?

hahahah niiiice.


PS.....I just did some tuning and I recreated your "burp" LOL Coupler popped off but enough air was still going through the MAF to keep it running. On the plus side I saw a nice drop in MAF Hz since I ran more 4" tubing in front of the MAF....maybe there is hope for me yet. Now if I could just keep the couplers together