NoPistons -Mazda Rx7 & Rx8 Rotary Forum

NoPistons -Mazda Rx7 & Rx8 Rotary Forum (https://www.nopistons.com/)
-   2nd Generation Specific (https://www.nopistons.com/2nd-generation-specific-17/)
-   -   stall when weight shifts forward D: (https://www.nopistons.com/2nd-generation-specific-17/stall-when-weight-shifts-forward-d-74485/)

NAFC 07-18-2010 07:07 PM

i used to think i had a vac leak somewhere around my brake booster, but i mean it works fine and the hoses and clamps are new anyway. i also did a little test where i just sat there and pumped the brakes in an attempt to recreate the stall at a stand-still.



I've come to learn that it stalls ONLY when the weight shifts forward. i tried wigglin' the AFM, i tried shakin some harness spots, i even parked facing DOWNHILL and nada. maybe it was a wire behind the pedal? nope.



i did some forum surfin across many different cars from domestics to civics, all with ridiculous solutions; "maybe its your cams".... yeah.



any ideas??

Baldy 07-19-2010 07:16 AM

Do you mean when you're braking? Or just letting of the gas?

RONIN FC 07-19-2010 03:03 PM

Does your car backfire? Theres a thing that keeps your throttle from slamming shut and causing stalling and backfires. Maybe its broke or out of adjustment.

I think its called a dashpot?https://www.nopistons.com/forums/pub...1047683561.gif

NAFC 07-20-2010 06:24 AM

ah I probably should've mentioned a few things :/



I've removed all the egr stuff, any possible vac line, the first butterfly valve in the tb, the bac, dashpot, the actuators on the lower intake, and I raised the idle to compensate for the rpm dip when using power steering.



everything's been workin fine for aboot the last year, I should also mention im using a diff brake booster, one that came with the new shell I swapped a good majority of my old stuff into.



n yes, I mean when braking https://www.nopistons.com/forums/pub...#>/biggrin.gif

Baldy 07-20-2010 07:04 AM

Ahh, so braking causes it to stall. I'm guessing this is a vac/BAC valve issue. When you brake you're suddenly using a bunch of vacuum, and without the BAC, the idle just drops instantly.



Or I could be full of crap, but there's my guess.

1988RedT2 07-20-2010 08:21 AM

Do a little experiment. Pull and plug the vac line to the brake booster, then in a safe place at a reasonable speed, nail the brakes and see if it happens?

NAFC 07-20-2010 07:38 PM

lol I had another buddy tell me to do the same test with the brake booster plug'd but it sounds soo sketchy hahaha I've tried brakin when my cars off and its the most difficult thing I've ever experienced hahaha



I don't think it's bac related cos I removed it ages ago, I didn't have a/c or p/s at the time, and I hated how often the bastard blew on me and gave me hours of frustration. since then I did get p/s and I simply raised my idle to make up for the 100/200 rpm dip. never have I ever had a problem since :] I also hated changin the pointless coolant hose going across it too.



the vacuum only goes one way and that's out from the booster, right? im pretty sure it feeds the engine air rather than suckin air cos my idle actually goes up when I press the brakes. if the bac opened, it would simply cause the idle to go even higher if that was the case :P



im gonna try that dangerously sketchy test and see what happens lol it only happens after I've been usin the brakes for a while, it doesn't stall right away or even sputter. nothin happens if I sit there and pump it either besides the idle spike from the surge of air comin in.



just for the sake of playing clue, I got a wideband o2 and a numerical gauge to help me find out if I have a gas or air problem :O


All times are GMT -5. The time now is 01:41 PM.


© 2024 MH Sub I, LLC dba Internet Brands