BADRX4

help help help!



I am extremely frustrated - I have a new s5 13bt rx7 block reasonably large bridgeport running N/A with a brand new 48mm IDA in my Rx4 Sedan.



The idle speed drops to just off a stall when you are driving and you brake and clutch it for a stop sign. It sounds like it is going to 1-rotor when this is happening - it appears to be the back rotor which is starving of fuel under brakes. Once you have stopped it takes about 10-15 seconds for the revs to climb again to its 1900rpm normal idle speed.



We have fiddled with the float level to no avail (including to the point it was over fuelling and dripping out the bottom of the ida!). Fuel press is 3.5psi with engine off / not running.



This is really frustrating and I am at loss to know why its doing this, any assistance from you weber gurus would be appreciated - if I can sort this problem I will be happy. The engine itself makes great performance and pull strongly through the rev range / this idle / braking prob is the only thing I need to sort.



FYI my IDA runs the following specs:



42mm Chokes

aux vent 4.5

main jet 210

air corr jet 120

emulsion tube F7

idle jet 70 F10

pump jet 70

pump bleed 0

Needle Value 320









Thanks for your help

Lynn E. Hanover

The first thing to do is to remove the plastic filter under the brass nut above the needle seat. Usually they plug up instantly on startup. Mount an inline filter close by the carb and change it often. Watch you mixture at full power, and see if the fuel level is close to none in the bowl.



Lynn E. Hanover

Maxt

Do you know if its going rich or lean during braking, used a wideband?.. How is the manifold angle in the car, the carbs level?

RONIN FC

This car have a power brake booster?



It could be interrupting vac signal to that runner/carb.

mullins

This sounds like float level is set too high. I have had this effect before myself and cured it by lowering the level.