grohgreg

I disagree. The car doesn't "want" anything. It merely performs according to what and how it's fed. The Pro+Boost box is really only a selectable menu of different feeding patterns. I will however agree that ambient temperature affects fuel density. My suggestion is to watch the weather forecast for the next triple digit threat. Switch to Map 0 the night before, and see if the problem doesn't turn out to be the boost sensor or some related component.

Have you inspected your air filter element by the way?

//greg//

canon_mutant

Was 97 today and no problems. It was like 103 a few days ago when I had the issue.

But, yes, as I stated above, I do intend to turn off the BSP the next time it happens to see if it's the Cayenne or the BSP?

Hard to believe that I would be performing so incredibly well on both acceleration and mpgs if there is some problem with the Cayenne "generally". Just something about the 103 degree day . . . there was a severe bog getting on the interstate and then it downshifted 2 gears and took off like a bat outta hell, and noticeable bog taking off each time I had to stop in traffic.

Oh, and air filter is like new . . . only 5K on the clock.

grohgreg

I'm still thinking that triple digit ambient temperatures are outside boost sensor parameters. The colder the air, the more dense. Obviously, there is more air entering the engine at lower temperatures than there is at higher temperatures. And when there's more air going into the engine, the ECU provides more fuel. That's the basis for my suspicion that the ECU settings for North America don't take triple digit ambient temperatures into consideration. Hence, less air means less fuel means turbo/fuel starvation.

I'll speculate that hot climate Cayenne Diesels have different ECU mapping relative to temperature versus fuel/air supply. I doubt that any dealer will tamper with the ECU, so it's a matter of (a) living with it, or (b) having the ECU professionally remapped. That said, you could speak with Jason at BlueSpark to see if any of the 9 maps may be compatible with this triple digit issue. Once the Bluetooth version is on the street, it will be a much simpler proposition to change mapping on the fly.

//greg//

canon_mutant

Makes sense . . .

I need to develop a plan of attack here. Even though it's running OK, the wife and I went to my brother's 60th BD party last evening and only got 31 and change mpg. All between 60 and 70mph and not much wind to speak of so something is just wrong. Should have been over 36.

Could be I had something thermal in the BSP itself that the 103 temp took out but it's all speculation until I start debugging.

Will update when I learn more . . .

grohgreg

Open the hood and verify that the blue LED is still flashing.

//greg//

endless_corners

People getting 36... Do they have more miles on the engine? Diesels need a few thousand miles at least to season.

grohgreg

That's with the tuning box. I'm at ~6400 miles, and have seen 36.2 twice recently

//greg//

endless_corners

right.. i know you got that which is muy bueno.. but the other dude only getting 30 what are his miles.. is his engine brand new?

gnat

Me? 30 is my overall for a whole tank (and really it was 28 or 29 when I calculated the value manually) but the best I've seen is 36.3 over an 80 mile trip. My engine is shy of 6k so far. You are right that diesels take awhile to fully break in, but I think it will be awhile yet before any of us here in the states have gotten 20k behind us. I'm excited to see what happens at that time though.

Van1

Wonder why Porsche would leave so much power and fuel economy on the table?

endless_corners

Gnat I was talking about canon mutant complaining he isn't getting 36. I was wondering if his engine was brand new. because it sounds like mid 30's should be repeatable when trying to hyper mill on the interstate.

canon_mutant

Sigh . . .

I was getting 35-36mpg easy at these speeds, got up to 103 the other day, the car ran like crap, and now my mpgs are down.

Where did I lose you?

endless_corners

Sorry missed that post on the first page. #badform #mybad

canon_mutant

Problem was probably me . . .

You know that nice cloth cover that comes on the BSP? I left it on. Duh . . .

Got all the cables nicely routed and the unit nicely tie wrapped in the notch of that plastic just to the right of the engine cover but didn't take the cloth cover off first. Was likely getting too hot though I won't know for sure until we get 3 digit heat again . . .

canon_mutant

So, has anyone else had any 100+ degree performance issues yet?

I have now learned that mine are NOT the BSP or my moment of temporary insanity leaving the cloth bag on the unit while installed.

Since the dealer made me remove it before they'd work on the vehicle before we left on our trip, I left the BSP off for this trip to CO to get "without" data points that I can compare to "with" data points later on when we go back.

Yesterday and today it was 101 and 103 respectively here and I had the extreme doggy-ness problem again and the BSP is still not on the vehicle.

I also have a number of extremely high cooling fan revs, one after just starting the vehicle. Wasn't a cold start but it had been cooling down for a couple hours at least . . . though nonetheless cooling down in 100+ heat.

And, no it's not overheating at least if the oil and coolant gauges are accurate.

Just weird that it could be "so specific" with temperature. Ran fine coming home from CO even though we ran into 98 degree heat through the last 1/3 of the trip as we got closer to home. Made us want to turn around and go back pretty badly since the cabin was 45-60 degrees up at 9000 ft for the entire week. Unusually cool for even that altitude the week of July 4th.

Get above 100 degrees though and the thing takes turbo lag to a whole new level, mpgs go down, along with the occasional over-rev of the cooling fans. Going in for an oil change so I'm going to log it as a problem when I go. We'll see if anything can be done . . .??

Since my dealer won't work on it otherwise, I just have to leave the BSP off for a while longer is all . . .