Car Stalling When Foot On Brake

[mikka91]

hey guys have a problem where the revs would drop when id use the brakes, just before id used the brakes then it would stall and lost all power (ALL electrics) to the car wif the battery still connected, tried a few batteries but no change.

has anyone encounted this problem

HELP

thanks

[tiberis]

rev drop with brakes would be linked to the fact that our brakes are 'power assist brakes'. ie they use the vacuum from the engine to help you push down the pedal.

there should be a hose from your brake booster to the intake plenum which provides the vacuum. if this hose is cracked/ damaged/ your brake booster is broken then when you press the pedal, it's letting air into your engine that the ecu doesn't know about, which leans out the mixture and the engine dies.

is the electric issue a direct result of the brakes/ engine issue? your wording there seems a bit unclear to me. after braking the engine dies and electrics die? or before stalling but after braking?

[mikka91]

well first of all if id hit the brakes the revs would just drop. later on in the day id do it again and it stalled the engine and i notice the clock was off, so i thort my battery terminals were loose, (they have not been on properly all day) but connected them up properly and still nothing. so i think iv blown some fuse/relay for my positive terminal or main power??

[rich81]

well first of all if id hit the brakes the revs would just drop. later on in the day id do it again and it stalled the engine and i notice the clock was off, so i thort my battery terminals were loose, (they have not been on properly all day) but connected them up properly and still nothing. so i think iv blown some fuse/relay for my positive terminal or main power??

Like tiberis said, rev drop can be caused by leaking vacuum hose between booster and plenum... used to happen to me in my -33 when I had a busted hose. I'd be almost 100% certain that's what's causing that. As for the power thing..... wouldn't have a clue, I can't thing of anything brake-related that'd do that, apart from maybe a short in the brake light wiring? But I wouldn't have thought that'd knock out all electricals in the car.

I'd just start picking through your fuses looking for a blown one to begin with.... never know, it could be a wild coincidence, blowing a main fuse and engine stalling due to vacuum leak at the same time.

I'm no expert, that's just what it looks like from where I sit :-)

[mad082]

the loss of power thing may possibly be caused by an alternator issue, but then you would know because the battery would be flat all the time, so it isn't likely.

[tiberis]

+1 for checking fuses.

It says you have an S13, so fuses are behind the kick panel in the driver's foot well and there are some main ones in the engine bay near the battery.

check over both sets for any that are dead/ look funny. most of the major electrics ones are in the engine bay set. (there should be a translation diagram floating around the silviawa.com forums, otherwise i have one and can post it up here for you).

faulty brake wiring *should* just blow a fuse, but if some one has gone to the effort of making them dodgy then who knows.

i would check the connectors to your battery as well, you have mentioned they are/ were loose. make sure there is no corrosion (powdery white stuff) around the terminals and make sure that when the terminal is on it's the right way up (yes, the terminals have a taper and are thicker at the bottom than the top) and that there is no carbon build up from any arcing that may have occurred when loose. also make sure the negative/ ground cable is fixed securely at terminal and engine.

[iseekool]

It's your brake booster hose or your brake booster is busted internally causing vacum leak.

I'm talking from experience having had a similar issue in my 83' Bluebird and the fundamentals R34 vacum isn't too much different too - So I imagine the the S13 will be quite similar.

- Change the hose first (cheapest and obvious) see if it fixes the problem - while you are at it change all the vacum lines - one thing I notice is that all the vacum systems are interconnected in some way - so a busted vacum hose in another spot could cause issues elsewhere in the car.

- Change your brake booster with a re-cond. or brand new one.

*IF* th issue is electrical.

- Check for lose connections.

- Ensure all grounding wire are connected.

- Check all fuses.

- Check for frayed wires - there could be an elecrical component that could be arcing when you apply the brake - brake light system is arcing somewhere in the body.

- If you have checked the basics above or unsure - best take it to an auto electrician.

[mikka91]

seem to have solved it

charge the battery over night, took a part of my 180 positive batter terminal the red plug, and seem to have fix it, but the one off the 32 looks visualy ok, so will have to clean the connection and retry it, as for the brake issue, it had alot of air in the lines, so i bled the brakes and all seems ok, no dramatic rev drop, and perfect starting up.

just a matter of stupid little stuff,

thanks to all for the input