Engine dies after hard braking

[dfrome66]

Hi - another problem with the same 91 navajo. When I brake hard and come to a stop, the engine dies. I've heard this may be related to a vacuum leak for the brake booster. Any suggestions on how to check this? Or is it something else entirely???

Thanks!
Delain

 

[dinks07]

Sounds like a vacum leak a big leak is easy to hear look at the hose off the booster and see what shape its in

 

[Roadrunner777]

I'd take off the hose at the brake booster and plug it. Now do a test brake (knowing of course that your braking distance and experience will be greatly different, safety first!)

If the engine is fine, then you need a brake booster. If the engine almost dies again, then my thoughts go to something weird in the gas tank maybe...

 

[FIND]

Spray brake cleaner on your vacuum lines at idle. If you hear the engine bog any, you have just found a vacuum leak.

 

[Stic-o]

I have the same problem with JP, it only happens in 4 low stopping down a steep descent.

 

[zukman]

had same issue in a 98 Expedition vaccum leak at the egr, little elbow rubber boot goes away very common problem but hard to figure out

 

[dfrome66]

Thanks for the suggestions. Pretty much confirmed my suspicions. I'll check it out this weekend.

 

[dfrome66]

So I checked for a vac leak at all the lines and booster. No vac leaks. However the problem still happens. Does anyone know if there is an idle upkick type of sensor that would increase the idle under a load? Or what about baffles in the fule tank. I had the fuel pump replaced a while back. Any suggestions would help...

 

[Roadrunner777]

Got a fuel pressure gauge? I'd hook it up, close the hood, do the hard stop thing so the engine stops and immediately get out and check the gauge. That should rule in/out fuel.