If the vacuum hose on the split second box would become slightly crimped (for a moment when saying going over a bump), what would you expect the result to be?

I don't want to post my symptoms yet because I hopefully want to confirm this was my problem by comparing it to what others think would happen. I suspect this was my problem since once I rerouted the vacuum tube, my problem has so far went away. Thanks for any help.

-Mark

 

were u on it in boost or just cruising?

 

Cruising

 

did you stall?

 

that was my guess^^ but if it were only for a second maybe it just sputtered or somethin momentarily??

 

on a cruise it is closed loop so it shouldn't do anything essentially. Running my SS box the tuning numbers in closed loops are pretty close to 10 (which is no adjustment) therefore it is pretty much stock fuel management.

I have mine pull a little fuel so at most it would go slightly rich but nothing that i would probably notice.

 

Basically it felt like a momentary fuel cut or hesitation, then fine. Now that I zip tied the tube so it can't crimp, I can't reproduce it - and I really put it through some serious tests.

 

well, what are your tuning numbers in the r4 when you aren't in boost? 10 means no adjustment in MAF, below 10 is pulling fuel and above 10 is adding fuel.

If you cut the pressure/vac off to the box it will go to zero so it will change from whatever number you are at to whatever number that is in that same rpm for 0psi.

Looking at my fuel map makes me think that crimping it wouldn't do anything. This week i'm going to test it though, i'll have someone ride in the passenger seat and crimp the hose when i'm driving.

 

If the line is crimped,the SS box wont know what vacuum or boost level you are at and will not be able to use the right portion of the map for fueling and timing.

 

My wife drove the Z into work today (30 miles or so) and the problem is completely gone. Before securing the vacuum line, the problem was easy to reproduce out on the road.

Just a little background - a few weeks ago I had the split second box pulled out of its resting place next to the battery so i could run the 4g power wire for the stereo I was installing. When I put the box back, I must have not pulled enough slack in the vacuum tube so it wouldn't get restricted.