Engine will die when I come to an abrupt stop

infiniti
q45

#1

The engine will die when I stop too quickly, its worse when the car is cold. Most of the time it will drop the RPM down below 500 and it struggles to bring them back up, sometimes it will right itself and some time it will die completely. As of now I just shift it into neutral when I come to a stop. Driving in traffic is really fun?. So I drive my automatic like as manual. Any ideas? Thanks for your time!


#2

When you post please give us
Make,model,yr,repair history and any related info


#3

How many miles on your Q45? What’s the maintenance history?

Perhaps there’s a problem with the Idle Air Control (IAC) system.


#4

Sit at idle and mash the brake simulating the kind of braking pressure you’re talking about when stopping quickly. If the car stumbles or stalls consider having your brake booster evaluated for a leak. If not, then like mcparadise the first thing I’d look at is the idle air control valve.


#5

1992 Q45 110,000 miles. got it from my grandma 3 yrs ago. i know the engine was replaced i think @ about 45,000. i had the transmission replaced @ 90,000. the front rack and pinion replaced @ about 85,000. that is the major stuff, i also had a stereo system put in.

what would i do to check the IAC syatem? Thanks!


#6

i will try this, but my remedy as of now is to shift into neutral to bring the RPM’s back up. now that i think of it, when i know i will have to stop suddenly i will shift into neutral and then mash the breaks so i kinda do this all day. am i mistaken the word idle to mean neutral? if so, what is idle?


#7

Neutral doesn’t equal idle but if you shift to neutral the car should go to idle or near it. All I was trying to suggest was that you find out whether or not it is related to the brakes themselves. Power brakes use assistance from the vacuum created by the engine. If the brake booster leaks this would count as a sudden, massive vacuum leak and could stall the engine.

If the same stops in neutral don’t present any problem for the engine then I would not suspect a brake booster.

A sticky idle air control valve could have something to do with it. These are easy to take off and clean.

Another possibility that comes to mind is a torque converter clutch that isn’t unlocking. Does this tend to happen mostly after you’ve been up to cruising speeds/top gear?

Maintenance history doesn’t mean past major repair work. It means things like how old are the spark plugs & wires, fuel filter, air filter…?


#8

wow, you guys are really cool to take the time to give me suggestions, i obviously know nothing about cars so thank you!

i will try these ideas and let ya know what happens. thank you so much for your time!


#9

This is obscure, but it happened to me once.

Water in gas tank. It was below the pickup in the tank, except when I hit the brakes and the water would slosh forward and rise up to the fuel pump inlet. The car would also sputter and stall right after filling it with fuel (stirring up the tank). That was my clue.