Questions for Turbo Masters part 2

[wolfrpi]

Hey guys I'm having a really weird problem with my 951 - it dies above 15 lbs of boost. The cut-off is so violent that sometime my tires actually chirp.

It all started after my battery went dead one night (left the lights on). After jumping it the car worked fine. Then the battery died again (left cell phone plugged in over night - which I used to be able to do). To start it this time I jumped it in reverse (costing backwards). The car ran like S*** until I turned it off and started it again (after battery had charged).

Now, the only problem is that it violently cuts out above 15 lbs of boost. It has the authority chips and it has never done this before. In fact, prior to the battery incident I was running 19 lbs daily.

I played with fuel pressure settings and MAF but neither adjustment stopped the problem.

Thanks for the help in advance.

Erick

[951EATS5.0]

do you have an aftermarket gauge? the Autothority chips are only supposed to boost to like 14 or 15, unless you may be one of the special people that know about the "pill"....

Here in michigan, our stuff corrodes,I had the exact same prob and traced it to battery wiring. turns out that when the battery wiring resistance goes up (due to corrosion) it affects the computer voltage. my car ran totally fine untill I got on it hard, and the total death! I replace all the major positve and negative wiring that I could find, changed all my fuses and then it was like new. no probs. since

[951EATS5.0]

by the way, don't buy one of those stupid "Porsche" bateries I can only get them to last a year, now I have an interstate, much better

[Blackfoot]

i'm no turbo master, more like an apprentice who has lots to learn. but it sounds like an electrical problem. did the car have this shutdown problem before the first batt charge? if not, maybe the dme was affected by the first recharge.

the other possibility i can think of is that the battery thing was coincidence, and maybe you have a hose leak somewhere that only manifests itself under high pressure.

[1.2gees]

I also think it's a loose hose or similar.

PS: I've had a genuine Porsche battery for over 2.5 years, with no records of replacement. It seems a bit weak if I let the car sit for over 2 weeks or so, but has been strong otherwise.
Ahmet

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It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

[wolfrpi]

I think its electrical only because it feels exactly like when you overboost and the injectors are "cut off". Like I said, the rear tires actually "chirp" - it's that much of a cut.

The battery is a special 13.5 lb dry cell unit. I don't believe it's the problem because it has performed flawlessly before.

I'm going to call autothority and see if this is a "limp home mode" of their chip.

Thanks,

Erick

[1.2gees]

I should specify, I think it's an electrical shutting of timing, or injectors, BECAUSE OF a loose hose, or an out of range readout from a sensor. Let us know what happens, and good luck.
Ahmet

------------------
It's all the driver...
My page over1g@hotmail.com
Porsche owners Gallery.../My 944

[Kaos]

Don't know if this applies here, but maybe you should check your TPS sensor. I don't have a turbo, but I did notice this problem:

If I power wash my engine bay, water gets in the TPS connector and shorts out the WOT switch. The car works fine until I go to WOT, at which point the switch is shorted to the closed throttle position, and the injectors shut off. Very unnerving. After tipping out from WOT back to part throttle, the car works fine.

I just dry the connector with electrical terminal cleaner, and everything is back to normal.

Again, this has no relation to battery voltage, but is an easy check with a multimeter set on continuity check.


Kaos 1985/2 N/A