engine sputters when I hit the breaks and eventually stalls

[bagnasco]

Hey guys. I would really appreciate the help if you can give it.

A little bit about my car first.

My car is a 1990 Nissan 240sx with an SR20DET "Black Top" engine, cold air intake, T25 turbo, and a bunch of other stuff done to it.

My problem is.......everytime i am driving around town, I will push the clutch in and hit the brakes to come to a stop at a red light. Well, when I do this my tachometer drops from a normal 750 rpm to 1000 rpm to 500 rpm and sometimes down to 0 rpm where it stalls....obviously.

I got home, opened my hood up and checked the brake fluid......It is a rustic brown color but it is still full. I havent flushed the brake system yet until I get an answer that maybe it needs new brake fluid.

After checking the brake fluid and seeing that it is still full, I turned the car back on, let it idle at 900 rpm (normal) and then hit the brake. I noticed everytime I hit the brake the rpm gauge would go down to about 700-800 rpm. This makes me think maybe its the alternator when the brake lights come on or maybe I need a new brake cylinder......but then I got to thinking that when I brake with the car still in gear (not in neutral) the tachometer does not go down to 500-0 rpm. This only happens when I disengage my clutch or shift the car into neutral.

Any help would be appreciated.



Modified by bagnasco at 4:49 PM 10/29/2008
Modified by bagnasco at 6:00 PM 10/29/2008

[ShaunakaRichard]

Personally I've never heard of what your describing. But I can give ya little info. For one thing your brake lights coming on will draw next to nothing. Not enough to have your alternator all the sudden max out. Not going to happen. And being low on fluid and etc has nothing to do with the way your motor is running. Those are "body" aspects of the car. Not the motor. Only way that the brake is connected to the motor is through the vacuum line going to the brake booster. All the advice I can give is turn up the idle. But to reiterate, your brakes have next to nothing to do with how your motor is running. Its bogging from something else.

[snake240]

if pressing brake causes this proble id look into the vacuum. thats how your brake booster works. it gets the vacuum it needs from the engine.

[psmith]

Do a search for IACV cleaning. Idle air control valve. That should solve your problem. Good luck!

[bagnasco]

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