1987 sentra

[gak63]

my son has a 1987 nissan sentra, 2 barrel carb, 1.6 ltr 4 cyl engine, 72,220 miles,we just put it back on the road, but when you step hard on the brake the engine stalls? is this a power booster problem? a vacuum problem or is the idle set too low, (engine surges a few times when it starts to warm up)

[way2old]

Hello and welcome to the forum. The 3 things you mentioned can all cause the problem of stalling. If stepping hard on the pedal causes it, and not normal brake application, I would suspect the booster as being the problem. Low engine idle will produce low engine vacuum, there by compounding the problem too. Use a vacuum gauge to adjust carb to get as much vacuum as possible out of engine and see if it helps. If it still stalls after adjustments, the booster is probably your problem. Let us know how much vacuum the engine is producing.

[DanD]

If the idle doesn’t change or become very rough when you’re holding the brake peddle on, while you are sitting still then its not likely a brake booster problem.
It could be that the idle is to low and the “normal” load from acceleration to braking is dragging the engine down to a stall.
What is the idle set at; is it near the spec?
As for there being a vacuum leak sure it could be and when you apply the brakes the vacuum that’s used to run the brake booster forces the stall.
But a vacuum leak depending on how big will normally cause a higher then normal idle that cannot be turned down by the idle screw.
Dan.

[re-tired]

Hey guys , I remember these cars having a prob with the anti- dieseling soleniod . It would quit working and you would have to lower idle too low too prevent run on. With it operating right , you can have the idle high enough to handle the extra load and still not run on at shutdown.