secondaries not opening..

[180sx-x]

for some reason my secondaries arent opening..is there any reason why? i did a search but to no straight answers...

[A20A1]

I hope you're refering to carb and not the EFI secondaries.


Well how are you testing the secondaries? Secondaries usually wont open when testing it by hand while the car is at rest.
Also there is a blocker on the throttle linkage that prevents the secondaries from opening untill the primaries have opened to a certain point first.

If you want to test the diaphragm hook a vaccum pump to the secondary diaphragm and see if the thorttle plate moves. At least this way you rule out the diaphragm as being faulty / leaky .

Then you need to move on to the thermowax valve to make sure it's closing at the appropriate temperature... if it doesn't close, the venturi vacuum that would have gone to the secondary diaphragm is bleed off thru the thermowax valve and that can cause the secondary not to open.

If you want you can remove the plastic vacuum "T" connection and the vacuum line that connects from the "T" to the thermowax valve.
Then run a new vacuum line from the secodnary diaphragm directly to the carb venturi vacuum port.
Plug the vacuum port on the Thermowax valve where you removed the vacuum line from the "T" just in case.

[cvergi01]

Yeah....what he said :)

[Michael Cote]

I did what A20A1 did and that fixed it on mine. To test it before hand I held the throttle open by hand (with engine off of course) and sucked through the line to secondaries. It opened so what he suggest was my next move. Works great.
Good Luck, Mike