Car stutters like two horny rabbits!!

[bosljeff]

NORMAL CONDITIONS:

At idle, boost is at 12 vacuum. At boost, I have boost set to 15 psi. All this has worked fine, until...

PROBLEM:

At any speed once boost is near 10 psi +/- car starts to stutter (seems to be fuel cut), muffler begins to pop, and car just generally jerks around until I let off throttle down to 5 psi or less.

But!!! Occasionally I can still hit 15 psi without stutter, but not very often, and when I do, the next time I try I can't get past 10 or so.

Car still idles at 12 vacuum, but occassionally dips even lower 17-20 vacuum, and no spiking that I can tell.

QUESTION:

It has been exceptionally cold here the last couple of days (0 to 10 below), is the boost just getting so much damn cold air I'm hitting fuel cut?

Ideas, thoughts, questions....

Thanks for your help and time.

Boz

 

[ASZRAEL1266]

it sounds like boost cut. With it being that cold the air is alot denser. Do you have a data loger? or super afc? with the new super afc you could get a rough idea of your knock but with a data loger you will know for sure.

 

[bosljeff]

Originally posted by ASZRAEL1266
it sounds like boost cut. With it being that cold the air is alot denser. Do you have a data loger? or super afc? with the new super afc you could get a rough idea of your knock but with a data loger you will know for sure.

Good to hear that the insanely cold air might be a factor. I don't have a data logger or afc, but I think I might try to turn down my boost and it has been warmer today so I'll do some "testing".

Thanks.

 

[bosljeff]

All is good. The day it was giving my problems it was as low as below freezing and today it is 30, and the car is "back to normal".

Sorry I panicked a little, but it is kinda cool to see what an impact cool, dense air can have on a turbo system. Better start upgrading my fuel system huh?

Thanks.

Boz