Car Stalls When Braking

[KPot2004]

1994 SL2, runs great but when I step on the brakes the rpm's go way, way low and sometimes it stalls and the engine shuts off. Any help would be greatly appreciated.

[sierrap615]

auto or manual? idle RPM? stalls at any speed or only when stoping. any other issues?

[KPot2004]

auto, idles at exactly 1000 rpm's, stalls only at stops, when the gas is not being applied

[atmalan]

I'm not sure, but maybe the float is gettin' stuck. That's why it doesn't die when you first start it and stuff, but only after you've been driving and applying the gas, then when you get ready to stop, the float could stick. Like I said, just a guess.

[SMC75]

I've been having the exact same problem for months...Been to the mechanic numerous times, they can't find a thing wrong with it. I just got the ECT replaced too per advice from this board. It's really frustrating. Do you notice it usually does it aorund the same places (usually)?

[KPot2004]

well besides the stalling every once in a while it drives great and runs great. I to replaced the ects, people have been telling me thats pretty much the sensor to fix everything

[sierrap615]

Originally Posted by atmalan

but maybe the float is gettin' stuck.

are you talking about a carb float? everything after 1990 is FI.

i would start by removing the intake from the thottle body, and cleaning it with carb and choke cleaner. focus on the hole at the bottom, the IAC(idle air control) is in that little hole.

[atmalan]

OH, was it 90??? I thought it was more like 95. My bad man, just mis informed knowledge on my part.

[sierrap615]

89, 90, 91 somewhere in there, some cars(including 91-94 saturn SOHC) use TBI (throttle body injection) which look very much like a electric carb. i have known people who mistake one for the other while looking right at it.

[karty72]

Try the EGR valve....I picked one up at a local salvage yard for 6 bucks. You'll also need a new gasket, which Autozone should be able to help you out with. I had the same problem with my '95 SL2, and the EGR valve cleared it up. But my Check Engine light would come on to warn me that 'something' was wrong.

[KPot2004]

my light is not on either

[Jess&Greg]

I had a car one time that did the same thing, and it turned out to be the torque converter. Just an idea. Good luck!

[shorod]

Originally Posted by Jess&Greg

I had a car one time that did the same thing, and it turned out to be the torque converter. Just an idea. Good luck!

It's not actually the torque converter that causes the problem, but the torque converter clutch (TCC). I'm not really familiar with Saturns (searching the forum for answers to a friend's Saturn woes) but often times the auto tranny will shift in to overdrive after maintaining a constant speed for more than 5 seconds or so. When doing this, the torque converter clutch locks the torque converter to optimize fuel economy. If the TCC fails (as they often did in GM products) the torque converter stays locked, even when approaching a stop. Since the driveline is now locked to the input shaft of the tranny, the engine bogs down and the car stalls.

To test this, check your service manual to find the location of the TCC connector and unplug it. If the car no longer stalls when approaching stops, the TCC is the problem. You can leave the TCC disconnected, but you will likely notice decreased fuel economy at highway cruising.

-Rod

[Nictoe]

One may as well have their belts snap, in cases like that. You're flying down the highway, and just like that NO power, NO brakes, NO Steering. Hairy as hell. More than likely, its an EGR valve problem...and it SUCKS BIG TIME.

[mysatilac]

Let me guess the problem only happens when the car is warmed up (after driving for 2-3 minutes)?

I agree with the first couple of people, it is probably your idle rpm.(or this may be a temporary fix till you find your problem)

Your throttle body has an adjustment screw (torx head) that the throttle cable rotor sits on (it is covered with a rubber cap)...
adjusting it gives your throttle body a new position when no gas is applied.

Also clean your throttle body, I turned the screw to fix the problem but then when I cleaned my throttle body it fixed the problem twice and I got really high idle rpm... ~2000

It would stay started when you first start the car, because your computer boosts the initial idle speed to warm up the engine, build oil pressure etc.


My initial idle speed is around ~1300 RPM
down to 7-800 rpm (perfect) when warm
If you have a constant idle of 1000 then you should probably go get tuned up.

This should fix the problem... but make sure you have enough brake fluid and all that (could be stressing your engine more than normal)
Good Luck!